QV Service Manual
Contents
1. 19v t t t t l cse c59 c78 1 sla D a A AL AL AL A U12 16 AZ AZ AZ a2 He 3 a3 3 3 3 m a4 M 4 l 18 TMS ast ms As ms ast ms as lo TMS as 4464 4464 AP 4464 4464 A7 A7 A7 A7 az 10 5 RAS RAS RAS RAS Ras cas cas CAS Cas cas 16 px vs VR wH ve 0123 0123 0123 0123 mime m se w NCNCNCNC 5 v 6 spe upo 17161914 E His 3210 7654 1109 8 15141213 19181617 23222021 n4 as 3 Rae 86 774 DIG AUDIO DATA 1 0 RA2. T comes 57 5 F T EE E 2 K 8 ToU pin 38 mos MM OO TM n Sek l Fy FE ix Ld I 1000 E i I 7 we 21 LEFT INPUT KO laj ind HN 47u sek J13 LJ 4 v gt 55 kas ze 4708 u a 7 srt Je UE 1 bssox T ke el AUDIO s u B EB e css E da SIGNAL mi PIEZO ce u DISPLAY ae 2101 INPUT LEVEL gt gt J pes E 3 ger 3 eal leg Suso ux EI m N 7 12 n 2 MIDI IN JTO F eme ver ert e rae lt PM SAMA Raj lt a an 750k Bypass an 775 s UZI PIN 14 47K A asv 856 AIK ou EPOR van T E E gu MIDI DUT 33K wee 47K R73 PROGRAM ADVANCE 20K a 801 PIS Hn 3 01 PIN 15 47K ven un 0 7 cea Dia LI 7612 6 a a atu gt 1 1 v v a RAW 10 VDC me s 5 VDC 7805 m BYPASS CAPS TYP ar ci8 ced v v 95 we cs m a s IZVDC 4704 7912 L cs MDE
3. MOD 1 TARGET 2 0 198 MOD 1 AMPLITUDE 3 0 126 MOD 2 SOURCE 4 0 2 MOD 2 TARGET 5 0 198 MOD 2 AMPLITUDE 6 0 126 MOD 3 SOURCE 7 0 MOD 3 TARGET 8 0 198 MOD 3 AMPLITUDE 9 0 126 MOD 4 SOURCE 10 0 MOD 4 TARGET 11 0 198 MOD 4 AMPLITUDE 12 0 126 MOD 5 SOURCE 13 0 MOD 5 TARGET 14 0 198 MOD 5 AMPLITUDE 15 0 126 MOD 6 SOURCE 16 0 MOD 6 TARGET 17 0 198 MOD 6 AMPLITUDE 18 0 126 MOD 7 SOURCE 19 0 MOD 7 TARGET 20 0 198 MOD 7 AMPLITUDE 21 0 126 MOD 8 SOURCE 22 0 MOD 8 TARGET 23 0 198 MOD 8 AMPLITUDE CONFIGURATION 7 Not used Modulation target values are dependent on the current configuration and mode of a program The most significant nibble determines the function being modulated as follows OXH REVERB MOD IXH DELAY MOD 2XH PITCH MOD 3XH EO MOD 4XH MIX MOD 5XH MULTI TAP MOD Configuration 3 only 6XH possible modulation targets within each of the above is follows Alesis QuadraVerb Service Manual 27 REVERB CONFIGURATION 0 1 4 5 6 nothing in 2 3 amp 7 Target PLATE ROOM CHAMBER HALL REVERSE 00H IN MIX IN MIX IN MIX IN MIX IN MIX OIH PREDLY PREDLY PREDLY PREDLY PREDLY 02H PRE MIX PRE MIX PRE MIX PRE MIX PRE MIX 03H DECAY DECAY DECAY ODECAY REV TIME 04H DIFFUSION DIFFUSION DIFFUSION DIFFUSION DIFFUSION OSH DENSITY DENSITY DENSITY LOW DEC DENSITY 06H LOW DEC LOW DEC LOW DEC HIGH DEC LOW DEC 07H
4. Alesis QuadraVerb Service Manual 23 0 99 DEPTH 0 99 FBACK 0 1 TRIGGER 0 99 DEPTH page 0 1 300 RING MOD SPECTRUM 1 0 198 RING MOD OUT MIX 2 0 198 RING MOD DEL REV MIX CONFIGURATION 6 page 0 0 1 RESONATOR GATE MODE 1 0 99 RESONATOR DECAY 2 0 60 RESONATOR 1 3 0 60 RESONATOR 2 4 0 60 3 5 0 60 RESONATOR 4 6 0 60 RESONATOR 5 FUNCTION 4 CONFIGURATION 0 amp 4 page 0 20 999 LOW FREQUENCY 1 0 560 LOW BOOST CUT 2 200 9999 MID FREQUENCY 3 20 255 MID BANDWIDTH 4 0 560 MID BOOST CUT 5 2000 18000 HIGH FREQUENCY 6 0 560 HIGH BOOST CUT CONFIGURATION 1 page 0 0 26 HIGH ROTOR LEVEL CONFIGURATION 2 page 0 0 28 16Hz 1 0 28 32Hz 2 0 28 62Hz 3 0 28 126Hz 4 0 28 250Hz 5 0 28 500Hz 6 0 28 IKHz 7 0 28 2KHz 8 0 28 4KHz 9 0 28 8KHz 10 0 28 16KHz CONFIGURATION 3 page Alesis QuadraVerb Service Manual 24 20 999 LOW FREQUENCY 0 560 LOW BOOST CUT 20 500 LOW MID FREQUENCY 20 255 LOW MID BANDWIDTH 0 560 LOW MID BOOST CUT 200 9999 MID FREQUENCY 20 255 MID BANDWIDTH 0 560 MID BOOST CUT 2000 18000 HIGH MID FREQUENCY 20 255 HIGH MID BANDWIDTH 0 560 HIGH MID BOOST CUT 2000 18000 HIGH FREQUENCY 0 560 HIGH BOOST CUT tA LNR gt CONFIGURATION 5 6 amp 7 Not used CONFIGURATION FUNCTI
5. CAB 12PINSIL3 0 1CTR 419032 2 4 1 1 MAINKEY CAB 6 PINSIL6 4966 CAB 12PINSIL7 0 1CTR 4190732 1 CAP 07 MFCERDISC 7 J 020104 21 7 54 57 64 66 73 578 CAP 1000 8006 f4 7C17181920 CAP 470 MFELEC25V 5547 4 C21 22 2324 CAP 47 MFELECSOV 1 575 17 5 CER 150 PECERDISG 5211 4 1026 27 4751 CER 180 PFCERDSC 7 6 020181 8 7 28 30 55363742444 CER 20 PFCERDSC 200 3 CER 30 PFCERDISG 1020331 1 MAIN CER 43 PFCERDSC ww 10245 8 C 79 86 MAY SUB W 47 PF FIL 11000 PFFLM 12002 1 058 FIL oorMFFILM 12005 C414650 7 6 200004 6 C45 52 53 55 56 65 7 0 0 FIL 12200 PFEILM 120 0222 2 C3940 iL 1 0022111 2025 1 0 FIL 8800 PFFILM 12532 2 89 HDR 14 PIN DIL HDR 010186 414004 1 5 MAN HDR 6 PINSILHDR 010186 44506 HDR 12PINSILHDR 01016 45012 5 jJ1 3 4 TWOONKEY PCB jLOCK HDR JI2PINSILHDRRA01 45043 1 JPorPB POT HDR 6 PINSILHDRRAO 44506 1 12 HDV 6 32x1 4 PP BLKUNC 5000 9 JGAS 7 6 32x1 4 PF BLK UNC 50004 4 PP HDV BEZEL SCREW 000012 4
6. 1 750 DELAY 0 7 TAP NUMBER 4 0 99 FEEDB 0 99 LFEEDB 0 99 FEEDB 1 1493 TAP DELAY 5 1 750 R DELAY 0 99 TAP VOLUME 6 0 99 R FEEDB 0 198 TAP PAN 7 0 99 TAP FB 8 0 99 MASTER FB CONFIGURATION 4 Not used CONFIGURATION 6 page Alesis Quadra Verb Service Manual 0 type 0 MONO l 0 198 IN MIX 1 5 2 PING PONG 0 198 IN MIX 0 198 IN MIX 2 1720 DELAY 1 320 L DELAY 1 320 DELAY 3 0 99 FEEDB 0 99 L FEEDB 0 99 FEEDB 4 1 320 R DELA Y 5 0 99 R FEEDB CONFIGURATION 7 page 0 0 2 SAMPLE PLAYBACK 1 0 150 SAMPLE START 2 0 155 SAMPLE LENGTH 3 0 1 AUDIO TRIG 4 0 2 MIDI TRIG 5 0 127 MIDI LOW LIMIT 6 0 127 MIDI BASE NOTE 7 0 127 MIDI HI LIMIT PITCH FUNCTION 3 CONFIGURATION 0 amp 3 page 0 type 0 M CHORUS 1 S CHORUS 2 MFLANGE 3 S FLANGE 4 DETUNE _ 5 PHASER 1 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 WAVE 0 1 WAVE 0 99 SPEED 0 99 SPEED 0 198 0 99 SPEED 0 99 SPEED 0 99 0 99 0 99 SPEED 0 99 0 99 0 99 0 99 0 1 TRIGGER CONFIGURATION 1 0 0 99 SEPARATION 1 0 1 2 0 1 SPEED CONFIGURATION 2 amp 7 Not used CONFIGURATION 4 page 0 type 0 CHORUS OFF 1 CHORUS 1 0 1 WAVE 2 0 99 SPEED 3 0 99 DEPTH CONFIGURATION 5
7. Display Unit locks up power up and down Troubleshoot if necessary Bad 80C31 Replace and re test Bad 24MHz Crystal Z1 Some crystals are shock sensitive Tapping on the crystal can sometimes reveal this or hot ram caps and replace if Bad LCD cable Replace and re test No Memory Bad battery Replace and re test Check R61 per section 2 1 Be aware that most battery failures are caused by a component failure on the board Bad reset circuit Check reset U21 pin 9 both during power up and down Troubleshoot if necessary Distorted audio Bad power supply rail Check PS rails and troubleshoot if necessary Faulty DASP 24 ASIC Replace and retest Faulty trace particularly between the Troubleshoot and replace if necessary DASP 24 ASIC and the DAC or analog switch U9 y ULQ 22222 21 Faulty op amp Troubleshoot and replace if necessary Faulty analog switch U9 Troubleshoot and replace if necessary Faulty power supply bypass capacitor Troubleshoot and replace if necessary particularly the cap at the analog switch U9 TTT m r TTT A few final notes The DAC output is an extremely important test point Familiarity with the appearance of this signal on a scope will greatly facilitate troubleshooting audio problems Exercise caution when examining the output of comparator U8 Accidentally shorting pins 7 and 8 together Alesis QuadraVerb Service Manual will inst
8. Frequency Hz 10Hz 100Hz 100 SU 234567891 2 34 567891 2 34 567891 2 34 56 7891 QV Filter Bode Plot Diagram 9 Alesis QuadraVerb Service Manual 8 0 Helpful Hints amp Common Solutions Troubleshooting a complex device such as the QuadraVerb can range from the simplicity of looking seeing and reseating a loose cable to examining complex timing relationships of data and control and replacing the slightly bad latch The following chart is presented in an effort to relieve the beleaguered technician from having to discover some of the common fixes we have seen Please note that we only cover the most likely causes not all of them Customer Complaint Possible Failure Possible Action No Power No Lights No Life Bad Ram Cap We have found that the Examine the PCB for any burnt blue monoblock ram caps are unreliable and have since switched to ceramic disk only necessary Blown DASP 24 ASIC If this IC is extremely hot to the touch then it is faulty Bad 5V rectifier diode D12 The cathode should read roughly 10V with some ripple It has been noticed that 1N4001 seem to have problems and since then have started using 1N4003 diodes exclusively Unit lights up but there is no LCD Bad Reset circuit Check reset U21 pin 9 both during
9. 13 12 high until Q3 turns on pulling the input low When this occurs the output of 2nd inverter U25 pins 10 11 will also go low slowly due to the time constant of R95 and C32 The power off reset is similar When the 10V raw supply sinks below 7V Q3 is turned off allowing the input of the inverter U25 pins 13 12 to pull high via pull up R59 and thus the same for the output of the 2nd inverter U25 pins 10 11 Also note the tap between the two inverters running to the input of AND gate U26 pins 1 2 and 3 This prevents access to SRAM functions while in the reset condition thus preventing data corruption Alesis QuadraVerb Service Manual 4 3 Memory Mapped I O The QuadraVerb and many other Alesis products utilizes a memory mapped I O system in order to deal with the wide variety of functions that the 8031 needs to access During the write cycle of the 8031 data on the 8031 data buss is made available to a series of latches When the WRN pin 16 signal of the 8031 is enabled and A15 address s most significant bit is active the 3 to 8 line demux U23 is used to decode the 3 least significant address lines and send a strobe to the clock input of one of these latches Consequently data can be stored into a latch simply by writing a value into a memory location Note that in this scenario data is write only All input functions to the 8031 are handled through the 8031 s built in I O ports 4 4 Analog Input and t
10. 35 U8 2 4 13 35 U9 2 3 4 12 35 V VCA 2 7 16 Vcc 2 W writable control store 5 write 4 5 6 WRN 5 Z Z1 4 6 12 35 Zener 7 35 Service Manual History 6 28 94 1 00 First release Alesis QuadraVerb Service Manual 39 Alesis QuadraVerb Service Manual NOTES 40
11. 5 ncn eet ott t cod ttbi tenti tendi a a 14 10 0 Software History nintendo e te e ned 16 11 0 Quadraverb Plus MIDI Implementation System 18 12 0 Quadraverb Service Parts Listu uuu u essere aa ek nnne enne 34 yo c 37 Service Manual HIStory sc e ett et ee redo e 39 Alesis QuadraVerb Service Manual 6 1 0 QuadraVerb General Description The QuadraVerb and other digital reverbs achieve their results by slicing analog signals into segments and then converting them to a numeric value corresponding to the amplitude of the signal at that particular instant These values are then mathematically manipulated and stored at various locations in a memory loop for eventual playback By varying the placement and amplitude of incoming samples discrete time delays are achieved When mixed together and converted back into analog these delays simulate the reflections associated with natural reverbs and delays as well as non natural effects such as d reverse reverbs and L 1 lt gated reverbs The n I added capabilities of Outs Dry Low pass Output Sample an 80631 micro p CAS Filters Hold controller allow T m user manipulation and Ji i storage of algorithm z parameters as well as effects such as a DAC chorus and flange 1 Hold that require real time l T gt manipulation of algorithms Please ANTI A
12. 8 AMPLITUDE 2A DELAY MSB LEFT DELAY MSB TAP 2 PAN 68 MULTITAP MASTER FEEDBACK 2B DELAY LSB LEFT DELAY LSB TAP 2 FEEDBACK 2C FEEDBACK LEFT FEEDBACK TAP 3 DELAY MSB 69 MULTITAP NUMBER 2D RIGHT DELAY MSB TAP 3 DELAY LSB 6A IST DIGIT NAME 2E RIGHT DELAY LSB 3 VOLUME 6B 2ND DIGIT NAME 2F RIGHT FEEDBACK TAP 3 PAN 6C 3RD DIGIT NAME 6D 4TH DIGIT NAME 30 SAMPLE LOW MIDI NOTE TAP 3 FEEDBACK STH DIGEE NAME 31 SAMPLE HIGH MIDI NOTE TAP 4 DELAY MSB 6F 6TH DIGIT NAME 32 REVERB MODE TAP 4 DELAY LSB 70 7TH DIGIT NAME 33 TAP4 VOLUME 71 8TH DIGIT NAME 34 REVERB INPUT 1 TAP 4 PAN 72 9TH DIGIT NAME 35 REVERB INPUT 2 TAP 4 FEEDBACK 73 10TH DIGIT NAME 36 REVERB INPUT MIX TAP 5 DELAY MSB 74 DIGIT NAME 37 REVERB PREDELAY TAP 5 DELAY LSB 75 12TH DIGIT NAME 38 REVERB PREDELAY MIX 5 VOLUME 76 13TH DIGIT NAME 39 REVERB DECAY 5 PAN TI 14TH DIGIT NAME 3A REVERB DIFFUSION TAP 5 FEEDBACK 78 RING MOD OUTPUT MIX 3B REVERB LOW DECAY TAP 6 DELAY MSB 79 RING MOD DEL REV MIX 3C REVERB HIGH DECAY TAP 6 DELAY LSB 3D REVERB DENSITY TAP 6 VOLUME 7A PAN SPEED 3E REVERB GATE TAP 6 PAN 7B PAN DEPTH 7C TF blank Alesis QuadraVerb Service Manual 33 GROUP DESCRIPTION ALPARTNO GTYPER 5110 PCB MANUFACTURER NOTES ASSY MAIN ASSY 82044 1 MAINBOARD 27 ASSY KEYPAD ASSY 82204 1 KEYPAD BUTTON BOARD CAB 14 001 115010186 4 18 1214 1 5 oe
13. HIGH DEC HIGH DEC HIGH DEC HIGH DEC DELAY CONFIGURATION 0 1 nothing in 4 amp 7 Target MONO STEREO PING PONG 10H IN MIX IN MIX IN MIX DELAY L DELAY DELAY 12H 26 L FEEDB FEEDB 13H R DELAY 14H R FEEDB CONFIGURATION 3 Target STEREO PING PONG MULTI TAP 10H INMIX IN MIX IN MIX IN MIX 11H DELAY L DELAY DELAY TAP 1 DELAY 12H FEEDB L FEEDB FEEDB TAP 2 DELAY 13H R DELAY TAP 3 DELAY 14H R FEEDB TAP 4 DELAY 15H TAP 5 DELAY 16H TAP 6 DELAY 17H TAP 7 DELAY 18H TAP 8 DELAY 50H TAP 1 VOLUME 51H TAP 2 VOLUME 52H TAP 3 VOLUME 53H TAP 4 VOLUME 54H TAP 5 VOLUME 55H TAP 6 VOLUME 56H TAP 7 VOLUME 57H TAP 8 VOLUME 58H TAP 1 PANNING 59H TAP 2 PANNING 5AH TAP 3 PANNING 5BH TAP 4 PANNING 5CH TAP 5 PANNING 5DH TAP 6 PANNING Alesis QuadraVerb Service Manual 28 5EH TAP 7 PANNING 5FH TAP 8 PANNING 60H TAP 1 FEEDBACK 61H TAP 2 FEEDBACK 62H TAP 3 FEEDBACK 63H TAP 4 FEEDBACK 64H TAP 5 FEEDBACK 65H TAP 6 FEEDBACK 66H TAP 7 FEEDBACK 67H TAP 8 FEEDBACK 68H MASTER FEEDBACK CONFIGURATION 2 5 6 Target MONO STEREO PING PONG 10H DELAY L DELAY DELAY FEEDB L FEEDB FEEDB 12H RDELAY 13H R FEEDB PITCH CONFIGURATION 0 amp 3 nothing in 2 amp 7 Target M CHORUS S CHORUS M FLANGE S FLANGE DETUNE PHASER 20H SPEED SPEED SPEED 21H DEPTH DEPTH DEPTH 22H FBACK FBACK FBACK CONFIGURATION 1 Target 20H SEPARATION 21H MOTOR 22H SPEED CONFIGURATION 4 Target 20H SPEED
14. When this message is received a MIDI data dump will be initiated and the display will read MIDI DATA DUMP IN PROGRESS Upon completion of the dump the display will return to its previously displayed page INDIVIDUAL PARAMETER LOCATION FUNCTION AND PAGE VALUES The following lists give the parameter locations and ranges for each of the effects in each of the configurations The parameter associated with a particular function and page may be dependent on both the current configuration and the current mode of the effect e g chorus phase etc In conditions where a page relates to different parameters depending on the mode of the effect the parameters are listed in tables under each mode All parameters are offset binary values This means that a signed parameter with a range of 99 to 99 in the display is actually stored as 0 for 99 99 for 0 and 198 for 99 REVERB FUNCTION 1 CONFIGURATION 0 5 amp 6 page 0 type 0 PLATE 1 1 ROOM 1 2 CHAMBER 1 3 HALL 1 4 REVERSE 1 1 0 3 ANPUT 1 0 3 INPUT 1 0 3 INPUT1 0 3 INPUT1 0 3 INPUT 1 2 0 1 2 0 1 0 2 0 1 INPUT2 0 1 2 0 1 INPUT 2 3 0 198 IN MIX 0 198 0 198 MIX 0 198 IN MIX 0 198 IN MIX 4 1 140 PREDLY 1 140 PREDLY 1 140 PREDLY 1 140 PREDLY 1 140 PREDLY 5 1 198 PRE MIX 1 198 PRE MIX 1 198 PRE MIX 1 198 PRE MIX 1 198 PRE MIX 6 0 99 DECAY 0 99 DECAY 0 99 DECAY 0 99 DECAY 0 99
15. be necessary to bypass the wet to decrease the noise floor To do this remove U6 Add jumpers across C11 C12 from U6 pin 1 to pin 3 and from pin 5 to pin 7 see diagram 7 Alesis QuadraVerb Service Manual 7 8 DAC Adjustment Installation It may also be necessary to install a DAC adjust trimpot to decrease DAC noise The components required are a 250K trimpot R43 2 200K resistors R20 and R44 and a 1M resistor R45 See diagram 8 for locations 7 9 Increasing Output Gain It may be necessary to change the gain of the output stage to accommodate the users of some amplifier effects loops To do this change R11 and R12 to a value between 4 7K and 10K the larger the value the higher the gain The application of these items are left to the discretion of the technician 7 10 QV I P Filter Kit Installation The following update enhances the input filter of the Quadraverb by increasing the number of filter poles from 4 to 6 This gives a corresponding increase in the filter rolloff rate and eliminates problems encountered when using the QV with high bandwidth samplers such as the Ensoniq ESQ 1 the Roland D 50 or the EMU Proteus Here is a list of components that will be changed or added Component New Value Added Diagram R16 9 1 7 680R 2 4K sI sI sI sI N 033uF 1500pF 033uF CA 3300pF CB 01UF R20 200K R44 200K R43 250Ktrm Reguires special installation see below Reco
16. gt lt page gt lt value1 gt lt value2 gt lt value3 gt F7 lt function gt 1 reverb 2 delay 3 pitch 4 eq 7 config 8 mix 9 mod 10 name lt page gt 0 where is the maximum page for the selected function lt valuel 3 gt new parameter value in the following format Data B7 B6 B5 B2 BI MSB 7 5 A4 2 Al AO LSB Sent 0 7 5 A4 A2A1 lt 1 gt 0 A0B7B6B5B4B3B2 lt value2 gt 0 BIB00 0 0 0 0 lt value3 gt All parameters to be edited must be sent in this format 12 MIDI bytes regardless of the number of bits required to transmit the value of the parameter When the QuadraVerb receives this message 1t will edit the specified parameter to the new value and display it If the function and page selected does not exist in the current configuration the command will be ignored If the value received is out of range for the parameter selected the range will be limited to a legal value The function and page numbers for each parameter are shown in the next section Alesis QuadraVerb Service Manual 18 02 MIDI Data Dump F0 00 00 0E 02 02 lt program gt lt data gt F7 lt program gt 0 99 selects individual programs 100 selects the edit buffer gt 100 selects all 100 programs lt data gt is in a packed format in order to optimize data transfer Eight MIDI bytes are used to transmit each block of 7 OuadraVerb data bytes If the 7 data bytes are looke
17. incorporate a split data buss In other words most external data lines are separated from the main buss via a de coupling network R35 R84 90 C28 30 C35 37 C42 C44 This is to provide better RF suppression however it can also cause some unique situations Normal signals on this secondary buss will appear extremely distorted for digital signals and sometimes lead a technician to believe that there may be a bad latch even though all components on the buss are functioning properly Conversely a bad latch can load the buss in such a way that bad timing occurs corrupting data even though the signals appear normal 4 1 80C31 Micro Controller Circuit The 80C31 MPU controls all user interface functions of the QuadraVerb These functions range from handling the front panel buttons to continuously updating algorithm information to the DASP 24 ASIC Note that the 8031 data buss serves a dual purpose This buss multiplexes between low order addresses 1st 8 bits and data Latch U20 is used to hold the low order address half during 8031 read and write cycles The EPROM U19 is used to hold both program information and algorithm data The SRAM U18 holds system variables as well as user preset data The 12MHz 8031 clock is derived from the 24 2 clock 71 via a divide by 2 counter 1 2 024 MIDI I O is handled through the 8031 s built in RXD Read Serial Data and TXD Transmit Serial Data ports Front panel keypad decoding is
18. 0 60 LOW DEC 8 0 60 HIGH DEC 0 60 HIGH DEC 0 60 HIGH DEC 0 1 0 60 HIGH DEC 9 0 1 GATE 0 1 0 1 ON 0 99 GATE 10 0 99 GATE HLD 0 99 GATE 0 99 GATE 0 99 GATE REL 11 0 99 REL 0 99 REL 0 99 REL 0 99 GATE LEV 12 0 99 GATE LEV 0 99 GATE LEV 0 99 GATE LEV DELAY FUNCTION 2 CONFIGURATION 0 page 0 type 0 MONO 1 STEREO 2 PING PONG 1 0 1 INPUT 1 0 1 INPUT 1 0 1 INPUT 1 2 0 198 IN MIX 0 198 IN MIX 0 198 IN MIX 3 1 800 DELAY 1 400 LDELAY 1 400 DELAY 4 0 99 FEEDB 0 99 LFEEDB 0 99 FEEDB 5 1 400 R DELA Y 6 0 99 R FEEDB CONFIGURATION 1 5 page Alesis QuadraVerb Service Manual 21 0 type 0 MONO 1 STEREO 2 PING PONG 1 0 198 IN MIX 0 198 IN MIX 0 198 IN MIX 2 1 800 DELAY 1 400 LDELAY 1 400 DELAY 3 0 99 FEEDB 0 99 LFEEDB 0 99 FEEDB 4 1 400 R DELAY 5 0 99 R FEEDB CONFIGURATION 2 page 0 type 0 MONO 1 STEREO 2 PING PONG 1 0 1 INPUT 0 1 INPUT 0 1 INPUT 2 1 1500 DELAY 1 750 L DELAY 1 750 DELAY 3 0 99 FEEDB 0 99 LFEEDB 0 99 FEEDB 4 1 750 R DELAY 5 0 99 R FEEDB CONFIGURATION 3 page 0 type 0 MONO 1 STEREO 2 PING PONG 3 MULTI TAP 1 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 INPUT 2 0 198 IN MIX 0 198 IN MIX 0 198 IN MIX 0 198 IN MIX 3 1 1500 DELAY 1 750 LDELAY
19. 01 NPNTRANS 29 41 6 06 MAN HARRISIMOTNAT 0592015 ME 40071 3 7 LED 1 KEY 12 ME PIEZO 01 1 KEWPOB KEY ME gt 701 0006 4 MAN ME 720001 1 j MTL 1 51 PANEL 903108 2 7 MIL COVER PANEL 90505 MIL JFRONTPANEL 19039 10186 Mo j j MIL REARPANEL PCB PCB GVMAIN REVF 94031019 1 ORNE PCB PCB QVKEYPAD 9440 1 PCB 9401021 PCB PCB QVPOT 2 1 STANDARD KNOB 9111001 2 6 SWITCHBOOT 71 PLS LCD BEZEL REVB 9111015 1 1 14 PLS POWERBUTTON PLS LED BUTTON 9111017 j PLS PLAINBUTTON 4 PLS SWITCHXTENDER 19111019 14 j POT MOKADUAL 009017 1 JPOTPCB DP POT POT 10689010 009100 1 JPOTPCB P 07 RES 18 5 0 000100 9 H1245 344586016 j RES 10K VW 5 10 00 0107 6 52 53 1 246 RES 100K 18 5 00514 2 95 RES JM 1 611 57 20005 3 567 MN BES 1 1K 1 81 5 0002 4 Alesis QuadraVerb Service Manual 35 RES 12K 1 8W 5 0 00 0123 R1 MAN RES 1 5K 18W 5 50052 RES 180K 18 5 00014 RES VW 5 0000200 5 IRI
20. 013353772738490 MA 20 aw 5 0 00 0208 9 H78243234457795 RES 20 1 8W 5 000021 10 R5056636467689194 RES 22 1 8W 5 00025 1 85 MAN RES SK 1 61 5 052 1 MN RES 3 3K 18 5 00552 2 upor RES 330K 18W 5 50354 7 RES 390K t eW 5 0000394 1 0 MAN RES 470 VW 5 00541 8 71 9114 15 17 18 546596 47K 8 5 0000472 j R2146495971747697 RES VW 5 00013 2 RAAB _ MAN WMoeoO E RES 510K 1 83W 5 00554 2 j RES 560 1 8W 5 20006 2 90 56K 1 8W 5 0052 1 BK RES 62K 18W 5 50062 Ii MAN RES 150 18W 5 0071 li 2 RES 18W 5 0000753 i 3 MAN RES 750K VaW 5 00574 1 Ran RES 82K 18W 5 002 6 8 5 0000913 o Jim JMN RUB RUBBERKEYPAD 93005 li JFEPASSY SOC gQ8PINDPOS 4400488 5 1756 SOC 28PINDIP0 6 406008 SB msm SOC 40 PINDIPO G 46000 lIi 14 MAN SOC ar PINASICSOC 4204 1 Wu PLCC SWT DPDTSWITCH 62001 j Alesis QuadraVerb Service Manual 36 10V 2 4 12V 1 5V 1 4 12 12V 1 1 12MHz 4 2 24MHz clock 4 6 4 4053 2 3 35 5 58256 2 7 7805 1 2 34 7812 1 34 7912
21. 1 34 8 8031 4 5 6 12 35 80C31 1 4 12 35 A A15 5 algorithm 1 4 5 16 analog switch 2 12 35 analog to digital 3 anti aliasing 2 3 Arithmetic Logic Unit 5 ASIC 4 5 12 13 35 36 audio pop 6 B backup 2 4 battery 2 4 7 12 35 bypass capacitors 1 C C1 2 34 C11 7 C13 6 C14 1 C15 1 C16 2 C17 C20 1 C2 2 C21 1 34 C22 1 C23 1 C24 1 C25 4 C28 30 4 34 C3 1 Index C31 1 C32 4 34 C35 37 4 C38 2 3 34 C39 2 34 C40 2 C42 4 8 C44 4 8 C56 5 C7 1 CA 8 9 CAS 6 CHORUS 1 17 20 23 29 clip LED 6 CLK 6 comparator 2 4 13 D D12 1 12 D13 1 D14 1 D15 4 7 35 D3 2 D4 2 D6 7 D7 4 DAC 2 4 6 8 9 12 13 16 35 DASP 24 2 4 5 6 12 data 2 4 5 6 7 12 DataDisk 6 13 DELAY 16 18 21 22 23 25 26 27 28 29 31 32 33 demux 5 34 DETUNE 23 29 33 divide by 2 4 DRAM 6 35 E EPROM 4 6 35 EQ 16 17 18 24 25 26 27 30 31 33 F FEEDBACK 29 33 FLANGE 1 23 29 33 I 4 5 Filter Kit 8 J J2 7 34 J6 1 35 L LC block filter 3 LCD 7 12 34 35 LED 2 5 6 7 34 35 Alesis Quadra Verb Service Manual 37 LESLIE 25 26 31 33 Lithium 2 35 LSTMSB 6 M MEM PWR 2 microprocessor 2 MIDI 4 6 7 12 16 17 18 19 20 23 33 35 MIX 16 18 20 21 22 23 24 25 27 28 30 31 33 Modulation 27 28 Most Significant Bit 3 4 5 M
22. 2 etc and finally through impedance fixing resistors 9 and R14 to the output jacks Note that some incompatibilities have been encountered when using the QuadraVerb with some particular amplifier effects loops If the customer is experiencing level drops when using the unit in such a setup it is possible to adjust the output stage gain to accommodate the amplifier see section 7 11 Alesis QuadraVerb Service Manual 3 1 Anti Aliasinq Filters Different QuadraVerb PCB revisions utilize 3 different types anti aliasing filters 10 eliminate Nyquist errors The 1st is a four pole active filter and will be seen on the oldest PCB revisions A through E If problems occur when using these older board revisions with digital synth s and some hot guitar pickups it will be necessary to upgrade this filter to a type 2 The type 2 filter is a six pole version of the active filler includes pre emphasis curve lt will only be seen on older board rev s that have been upgraded The 3rd type of filter is the LC block filter This single component filter is seen on revision F and later boards It eliminates the need for active circuitry as well as facilitating easier servicing 3 2 Successive Approximation Successive approximation is a heuristic approach to the process of analog to digital conversion The idea is to divide the process into short manageable sections Each significant binary weight starting wi
23. 21H DEPTH CONFIGURATION 5 Target 20H SPECTRUM SHIFT 21H RING OUTPUT MIX 22H DEL REV IN MIX CONFIGURATION 6 Target Alesis QuadraVerb Service Manual SPEED DETUNE SPEED DEPTH DEPTH FBACK 20H RESONATOR DECAY EQ CONFIGURATION 0 4 4 nothing in 5 6 amp 7 Target 30H LOW FREOUENCY 31H LOW BOOST CUT 32H MID FREQUENCY 33H MID BANDWIDTH 34H MID BOOST CUT 35H HIGH FREQUENCY 36H HIGH BOOST CUT CONFIGURATION 1 Target 30H HIGH ROTOR LEVEL CONFIGURATION 2 Target 30H 16Hz 31H 32Hz 32H 62Hz 33H 126Hz 34H 250Hz 35H 500Hz 36H 1KHz 37H 2KHz 38H 4KHz 39H 8KHz 7 CONFIGURATION 3 Target 30H LOW FREQUENCY 31H LOW BOOST CUT 32H LOW MID FREQUENCY 33H LOW MID BANDWIDTH 34H LOW MID BOOST CUT 35H MID FREQUENCY 36H MID BANDWIDTH 37H MID BOOST CUT 38H HIGH MID FREQUENCY 39H HIGH MID BANDWIDTH 3AH HIGH MID BOOST CUT 3BH HIGH FREQUENCY 3CH HIGH BOOST CUT Alesis QuadraVerb Service Manual 30 MIN CONFIGURATION 0 Target PRE EQ POST EQ 40H DIRECT MAST FX 41H MAST FX EQ 42H PITCH PITCH 43H DELAY DELAY 44H REVERB REVERB CONFIGURATION 1 Target 40H MAST FX 41H LESLIE 42H DELAY 43H REVERB CONFIGURATION 2 Target 40H MAST FX 41H EQ 42H DELAY CONFIGURATION 3 Target 40H DIRECT 41H MAST FX 42H PITCH 43H DELAY CONFIGURATION 4 Target 40H DIRECT 41H MAST FX 42H REVERB CONFIGURATION 5 Target 40H DIRECT 41H MAST FX 42H RING MOD 43H DEL
24. AY 44H REVERB Alesis Quadra Verb Service Manual 31 CONFIGURATION 6 Target 40H 41H 42H 43H 44H DIRECT MAST FX RESONATOR DELAY REVERB NAME FUNCTION 10 CONFIGURATION 0 4 page Oo o JI tA WN gt Q D O Alesis QuadraVerb Service Manual 32 127 1st DIGIT NAME 32 127 2nd DIGIT NAME 32 127 3rd DIGIT NAME 32 127 4th DIGIT NAME 32 127 5th DIGIT 32 127 6th DIGIT NAME 32 127 7th DIGIT NAME 32 127 8th DIGIT NAME 32 127 9th DIGIT NAME 32 127 10th DIGIT NAME 32 127 11th DIGIT NAME 32 127 12th DIGIT NAME 32 127 13th DIGIT NAME 32 127 14th DIGIT NAME PARAMETER ADDRESSES WITHIN PROGRAMS The following addresses are relative to the first address of a program These addresses assume that the data has been unpacked into byte values Blank locations should be left 0 00 LOW EQ FREQ MSB 3F REVERB GATE HOLD TAP 6 FEEDBACK D TA Eo ravo A 1 40 REVERB GATE RELEASE TAP 7 DELAY MSB 03 LOW AMP LSB 62Hz 41 REVERB GATED LEVEL TAP 7 DELAY LSB 04 MID EQ FREQ MSB 126Hz 42 RING MOD SHIFT MSB TAP 7 VOLUME 05 MID EQ FREQ LSB 250Hz 43 RING MOD SHIFT LSB TAP 7 PAN 06 MID EQ BANDWIDTH 500Hz 44 CONFIGURATION 07 MID EQ AMP MSB IKHz 45 PRE 00 POST 01 POST PANNING 10 POST 08 MID EQ AMP LSB 2KHz TREMOLO 11 09 HIGH EQ FREQ MSB 4KHz 46 DIRECT LEVEL EQ LEVEL OA HIGH EQ FREQ LSB 8KHz 47 MASTER EFFECTS LEVEL HIGH
25. Alesis QuadraVerb Service Manual Revision 1 00 6 28 94 Alesis QuadraVerb Service Manual 1 PREFACE This document is intended to assist the service technician in the operation maintenance and repair of the QuadraVerb digital effects processor Together with the QuadraVerb Reference Manual this document provides a complete description of the functionality and serviceability of the QuadraVerb Any comments or suggestions you may have pertaining to the document are welcome and encouraged READ THIS In addition to any purchase price that Alesis may charge as consideration for Alesis selling or otherwise transferring this service manual Manual to you if you are not a service and repair facility Service Center authorized by Alesis in writing to be an authorized Service Center Alesis sells or transfers the Manual to you on the following terms and conditions Only Service Centers authorized by Alesis in writing are authorized to perform service and repairs covered by an Alesis warranty if any and transfer of the Manual to you does not authorize you to be an authorized Service Center Therefore if you perform or if the Manual is used to perform any service or repairs on any Alesis product or part thereof any and all warranties of Alesis as to that product and any service contract with Alesis for that product shall be voided and shall no longer apply for such product even if your services or repairs were done in accordan
26. EQ AMP MSB 16KHz 48 PITCH LEVEL LESLIE LEVEL RING MOD LEV HIGH EQ AMP LSB 49 DELAY LEVEL OD LESLIE HIGH ROTOR LEVEL TAP 1 DELAY MSB AA REVERB LEVEL OE LOW MID EQ FREQ MSB 4B RESONATOR PITCH 1 TAP 8 DELAY MSB OF LOW MID EQ FREQ LSB 10 LOW MID EQ BANDWIDTH 4C RESONATOR PITCH 2 TAP 8 DELAY LSB 11 LOW MID EQ AMP MSB 4D RESONATOR PITCH 3 TAP 8 VOLUME 12 LOW MID EQ AMP LSB 13 HIGH MID EQ FREQ MSB 4E RESONATOR PITCH 4 TAP 8 PAN 14 HIGH MID EQ FREQ LSB 4F RESONATOR PITCH 5 TAP 8 FEEDBACK 15 HIGH MID EQ BANDWIDTH 50 MOD 1 SOURCE 16 HIGH MID EQ AMP MSB 51 MOD 1 TARGET 17 HIGH MID EQ AMP LSB 52 MOD 1 AMPLITUDE 18 SAMPLE START TAP 1 DELAY LSB 53 MOD 2 SOURCE 19 SAMPLE LENGTH TAP 1 VOLUME 54 MOD 2 TARGET IA PITCH MODE 55 MOD 2 AMPLITUDE IB PITCH INPUT 56 MOD 3 SOURCE LFO WAVEFORM 57 MOD 3 TARGET ID LFO SPEED 58 MOD 3 AMPLITUDE IE LFO DEPTH RESONATOR DECAY 59 MOD 4 SOURCE 1F SAMPLE PLAYBACK MODE TAP 1 PAN 5A MOD 4 TARGET 20 PITCH FEEDBACK 5B MOD 4 AMPLITUDE 21 DETUNE AMOUNT SAMPLE PITCH 5C MOD 5 SOURCE 22 LESLIE SEPARATION 1 FEEDBACK 5D MOD 5 TARGET 23 LESLIE MOTOR SAMPLE REC AUDIO TRIG SE MOD 5 AMPLITUDE TAP 2 DELAY MSB us 24 LESLIE SPEED SAMPLE MIDI TRIG 61 MOD 6 AMPLITUDE TAP 2 DELAY LSB 62 MOD 7 SOURCE 25 TRIGGER FLANGE RES MIDI GATE 63 MOD 7 TARGET 26 SAMPLE MIDI BASE NOTE TAP 2 VOLUME 64 MOD 7 AMPLITUDE 27 DELAY MODE 65 MOD 8 SOURCE 28 DELAY INPUT 66 MOD 8 TARGET 29 DELAY INPUT MIX 67 MOD
27. HORIZED ALESIS SERVICE CENTER SHALL BE SOLELY THE RESPONSIBILITY OF THAT ENTITY AND ALESIS SHALL HAVE NO LIABILITY TO THAT ENTITY OR TO ANY OTHER PARTY FOR ANY REPAIRS BY THAT ENTITY Alesis QuadraVerb Service Manual 3 SAFETY SUGGESTIONS Carefully read the applicable items of the operating instructions and these safety suggestions before using this product Use extra care to follow the warnings written on the product itself and in the operating instructions Keep the operating instructions and safety suggestions for reference in the future 1 Power Source The product should only be connected to a power supply which is described either in the operating instructions or in markings on the product 2 Power Cord Protection AC power supply cords should be placed such that no one is likely to step on the cords and such that nothing will be placed on or against them 3 Grounding the Plug This product has a 3 wire grounding type of plug a plug with a grounding pin for safety purposes This plug can only be used in a grounding power outlet If the plug does not insert into the outlet you are using the outlet probably is not a grounding type of power outlet Contact your electrician to replace the obsolete outlet with a grounding type of outlet instead of defeating the safety feature of the grounding type of plug 4 Periods of Non use If the product is not used for any significant period of time the product s AC power supply cord s
28. JNCWBEZE J 6INTSTARWASHER 51902 HEATSINKS HDW o95NYLONSPACER 5 01 0007 6 IHDW ZieSTARWASHER 15 01 0008 6 T 1 HOW 0 050 NYLON WASHER 15 01 0050 1 8RDSTANDOFFONSINK HOW 6 32x1 2 STANDOFF 502 0003 5 FPIHEATSINK 7 HDW esa2KEPNUT 5 02 6320 lo 7 How ANGLEBRACKETFP 5701 How HEATSINK 9 03 02 TT 1 0 0 HDW___ SOLDER LUG PCB MNT 19 03 1036 6 7 How CABLEBRACKET 19 13 1012 1 12441 IHDW JRUBBERSTRIP5IN 1 92506 2 LCDTOP amp BOITOM 220 220 220 16 PIN DIP 0 3 20 PIN DIP 0 3 20 PIN DIP 0 3 Alesis QuadraVerb Service Manual 34 74HC00 QUAD 2 IN NAND 2 14 7400 MAIN NAT TI 14 PIN DIP 03 14 PIN DIP 0 3 14 PIN DIP 0 3 18 PIN DIP 0 3 28 PIN DIP 0 6 28 PIN DIP 0 6 40 PIN DIP 0 6 14 PIN DIP 0 3 CEMaae1 221381 Mo IW MAIN CURTISS CS PINDIP 03 ANALOG COMP 2201 1 18 MAN TB PIN DIP O S 14 PIN DIP 0 3 16 PIN DIP 0 3 6N138 OPTOISO 24058 1 590 HPC PINDIP 0 8 28 PIN DIP 0 6 PLCC 84 4 00 0001 2 4PINDNJACK Pd 40004 1 MAIN MONO 45001 6 781114 LCD LCDMODULE 1 4148 SIGNAL DIODE 20448 8 D29 00 41 0 3 SPC ME 7 iNVOSPOWERDIODE 21403 5 4 17 D027 05 SPC 00 41 0 3 SPC ME 2N44
29. L AAA ol 24 s J4 PIN 5 8 6 Pse s RIS T eT ZEN bs 7 E J4 PIN 6 525 8 L AAA c44 1 1 6 J4 PIN 7 B 27 RIN WRN z e e lis p 15 26 56 5 LB 1 k B as 25 1 EN ho a E lan 24 5 50 nc if eke EE wen 618 NC E 77 ve an melk esv R54 96 i 8 eae 1 De 470 2 E 4 A go uds E ivv 9 4 3 RAW 10 C47 8 es 150 35 e 025 T B 24 MHZ Zi Di 8 D2 9 E m 3 O Ves D4 u 1 25 je R56 2208 D6 13 D7 14 C34 a 2057 20pF Da MEN per mH 1 nv lt VOLTAGE WHILE OFF lt 10K SPARES 6 m uez gt i 1 AIS 0 026 21 csi v v ues Alesis Quadra Verb Service Manual 15 10 0 Software History DATE VERSION COMMENTS 1 15 89 1 23 89 2 22 89 3 8 89 11 30 89 3 8 90 8 10 90 1 00 1 01 1 02 1 03 1 05 1 07 2 00 1 1 2 3 4 5 6 2 3 1 2 3 1 2 First production release Added test routines for production testing including RAM ROM LEDs MIDI and CLIP tests Fixed bug that caused a gated effect to be heard on graphic EQ and delay mode programs 1f the previously selected program was a gated program Fixed bug
30. LIASING note that there several different main PCB revisions so MEMORY DRAM BRIDE ZAK 24 differences will be EPROM SRAM DATA ASIC noticed from unit to unit Memory 2 0 Power Supply Mapped The power VO supply begins with the 9 Volt A C adapter Dry Input from J6 is R F Audio PIEZO fitered by C31 before Threshold MIDI on off switch S1 From there it is split for the 12V 12V and 5V rails The 12 rail consists of voltage Diagram 1 doubler C22 C24 and D13 D14 a 7812 regulator U31 and filter caps C3 C14 The 12V rail is a mirror of the 12V rail consisting of voltage doubler C21 C23 and D10 D11 a 7912 reoulator and filter capacitors C7 and C15 The 5V rail consists of a rectifier diode D12 filter capacitors C17 C20 a 7805 regulator and a multitude of 0 1uF bypass capacitors Note that the raw 10V line used by the microprocessor reset and the SRAM power supply when retrofitted and is located at the input to the 7805 regulator 2 1 Battery Backup Alesis QuadraVerb Service Manual QuadraVerb Simplified Block Diagram Battery backup is actually more complicated than it might first appear as it depends on a good system reset see section 4 2 for details in order to function properly The actual backup circuit consists of a battery 3V 3 6V Lithium a 10K resistor R61 for checking standby current see below a steering di
31. ON 7 page 0 0 4 CONFIGURATION EQ gt PCH gt DL gt REVERB LESLIE gt DL gt REVERB GRAPHIC EQ gt DELAY SBAND EQ gt PCH gt DLY 3 BAND EQ gt REVERB RING gt DL gt REVERB RESONATOR gt DL gt REVERB SAMPLING JI OQ KF C MIN FUNCTION 8 CONFIGURATION 0 page 0 type 0 PRE EQ 1 POST EQ 1 0 99 DIRECT 0 99 MAST FX 2 0 99 MAST 0 99 EQ 3 0 99 0 99 4 0 99 DELAY 0 99 DELA Y 5 0 99 REVERB 0 99 REVERB CONFIGURATION 1 page Alesis Quadra Verb Service Manual 25 0 0 99 MAST FX 1 0 99 LESLIE 2 0 99 DELAY 3 0 99 REVERB CONFIGURATION 2 page 0 0 99 MAST FX l 0 99 EQ 2 0 99 DELAY CONFIGURATION 3 page 0 type 0 PRE EQ 1 POST EQ 1 0 99 DIRECT 0 99 MAST FX 0 99 MAST FX 0 99 EQ 3 0 99 PITCH 0 99 PITCH 4 0 99 DELAY 0 99 DELAY CONFIGURATION 4 page 0 type 0 PRE EQ 1 POST EQ 1 0 99 DIRECT 0 99 MAST 2 0 99 MAST FX 0 99 EQ 5 0 99 REVERB 0 99 REVERB CONFIGURATION 5 page 0 0 99 MAST FX 1 0 99 DIRECT 2 0 99 RING MOD 3 0 99 DELA Y 4 0 99 REVERB CONFIGURATION 6 page 0 0 99 MAST FX 1 0 99 DIRECT 2 0 99 RESONATOR 3 0 99 DELAY 4 0 99 REVERB CONFIGURATION 7 page 0 0 99 DIRECT 1 0 99 SAMPLE Alesis QuadraVerb Service Manual 26 MOD FUNCTION 9 CONFIGURATION 0 6 page 0 0 126 MOD 1 SOURCE 1 0
32. PU 4 35 N Nyquist 3 O OPCODES 18 opto isolator 7 overflow 2 6 OVFLO 6 P PANNING 17 28 29 33 PHASER 23 29 PITCH 18 23 25 26 27 29 31 33 power supply 1 2 6 12 13 Q Q2 5 Q3 4 Q4 12 Q5 12 QuadraVerb 1 2 3 4 5 6 8 12 17 18 Quadraverb i ii 3 4 5 6 8 12 17 18 19 20 34 R R11 8 R12 8 R14 2 R16 4 8 9 R17 2 R18 2 R20 8 9 R26 8 9 36 R27 9 36 R3 2 36 R35 4 R36 6 36 R42 9 36 R42a 8 9 R43 8 9 R44 8 9 R45 8 9 R47 6 36 R48 6 R51 5 R58 4 R59 4 5 R6 2 R60 4 R61 2 12 R66 7 R84 90 4 R9 2 36 R95 4 RA 8 9 34 RAM 6 12 16 RAS 6 RB 8 9 read 4 12 regulator 1 2 4 reset 2 4 5 6 7 12 RESONATOR 24 25 26 30 32 33 REVERB 16 18 20 25 26 27 28 31 32 33 RF 4 RING MOD 24 26 32 33 RISC 5 ROM 6 16 RST 6 RXD 4 1 1 36 SAMPLE 2 3 4 6 17 23 27 33 sample and hold 2 3 6 SAMPLING 17 SAR 4 5 scope sync 4 self diagnostics 6 SRAM 2 4 5 6 7 35 standby current 2 STB 6 Successive approximation 3 4 5 System Exclusive 18 System exclusive 18 T trimpot 6 8 9 TXD 4 U U1 2 35 U18 4 35 U19 4 35 U2 2 Alesis QuadraVerb Service Manual 38 U20 4 35 U22 5 U23 5 34 U24 2 4 35 U25 4 5 35 U26 5 35 U3 2 9 U30 7 12 35 U31 1 34 U4 2 U5 2 13 35 U6 2 7 13 U7 2
33. REV TIME 7 0 8 DIFFUSION 0 8 DIFFUSION 0 8 DIFFUSION 0 8 DIFFUSION 0 8 DIFFUSION 8 0 8 DENSITY 0 8 DENSITY 0 8 DENSITY 0 60 LOW DEC 0 8 DENSITY Alesis QuadraVerb Service Manual 20 9 0 60 LOW DEC 0 60 LOW DEC 0 60 LOW DEC 0 60 HIGH DEC 0 60 LOW DEC 10 0 60 HIGH DEC 0 60 HIGH DEC 0 60 HIGH DEC 0 1 GATE ON 0 60 HIGH DEC 11 0 1 GATE ON 0 1 GATE 0 1 GATE ON 0 99 GATE HLD 12 0 99 GATE HLD 0 99 GATE HLD 0 99 GATE HLD 0 99 GATE REL 13 0 99 GATE REL 0 99 GATE REL 0 99 GATE REL 0 99 GATE LEV 14 0 99 GATE LEV 0 99 GATE LEV 0 99 GATE LEV CONFIGURATION 1 page 0 type 0 PLATE 1 1 ROOM 1 2 CHAMBER 1 3 HALL 1 4 REVERSE 1 1 0 2 INPUT 1 0 2 INPUT 1 0 2 INPUT 1 0 2 INPUT 1 0 2 INPUT 1 2 14 same as configuration 0 CONFIGURATION 2 3 amp 7 Not used CONFIGURATION 4 page 0 type 0 PLATE 2 1 ROOM 2 2 CHAMBER 2 3 HALL 2 4 REVERSE 2 1 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 INPUT 0 1 INPUT 2 1 140 PREDLY 1 140 PREDLY 1 140 PREDLY 1 140 PREDLY 1 140 PREDLY 3 1 198 PRE MIX 1 198 PRE MIX 1 198 PRE MIX 1 198 PRE MIX 1 198 PRE MIX 4 0 99 DECAY 0 99 DECAY 0 99 DECA Y 0 99 DECA Y 0 99 REV TIME 5 0 8 DIFFUSION 0 8 DIFFUSION 0 8 DIFFUSION 0 8 DIFFUSION 0 8 DIFFUSION 6 0 8 DENSITY 0 8 DENSITY 0 8 DENSITY 0 60 LOW DEC 0 8 DENSITY 7 0 60 LOW DEC 0 60 LOW DEC 0 60 LOW DEC 0 60 HIGH DEC
34. S 750 2 A0 A7 8 8 ig p VR Dd 6 83 40 PCM 54 44 00207 o AL 45 DO 30 MAI 81 AG 876 Ba sa D 46 D1 31 mao a2 mu 54 18 2 U10 a RW DASP e4 Sae seme 0 am LT ss 48 D3 32 78 smout 1 56 4 1 100875 5 4 49 04 35 MAS U1 77 A je 3 50 D5 36 mad 76 A7 5 16 60 51 D6 37 3 CD4053 6 2 21006 FEF 51 se 07 39 712 Paes 8 58 4 STATUS a NC 8 5 ho 220 VVvp 4 BINPUT LEVEL 28 shay La 4 PIN 9 EN 74 15 m anan 12v SV 4 1 42 RST DATA INPUTS ADDRESS INPUTS en iv v Bio s3 5 52 2143 8 pai 47k MD 0 7 MA 0 7 MA 8 uza ONI us IM ToU3pin8 o 2 5 3 Fin 7 4 c65 5 PIN 1C T BE a RENA T ES 270pF f J4 PIN 12 895 N 20 1 Cep 8 X 43pF 4 ueo 28 11 19 vi9 1 us 11 19 28 s 12 PLO LI 55V 5 o SV DATA DATA KAMA u TUUS 2 ao u PLI 285 3 38 14 14 20 10 PL2 m 2 9 4 37 20 07 sv J3 fee siis 12 36 E A R96 5 01 8 eese 26 IE A AMA cas uer e J4 i sak Mg 5734 27 512 SRAM Ls gt PLe 05 i3 PM vuo C36 aJno B 34 PIN 1 5 PL 26 2 1 J4 PIN 2 3086 9 7 Ras lina 7 FIRST 7 EVA C37 s ts J4 PIN 3 89 H R89 1 3 J4 PIN 4 esa 1 CEN AH AL DEN WN AH A
35. age The stereo signal is then sent to the outputs via the dry VCA U5 It is also summed to mono Via R17 R18 before being passed along to the anti aliasing filter discussed later and the LED control circuit The LED circuit consists of a rectifier U4 D2 a fairly standard comparator ladder U7 amp associated resistors and a one shot multivibrator U24 D3 etc to provide a time constant so that ASIC math overflow conditions stay highly visible The summed stereo signal after passing through the anti aliasing filter continues into the input sample and hold circuit The input sample and hold circuit consists of 1 3 of the 4053 analog switch U9 the input sample cap C38 a buffer amplifier U3 and a comparator U8 The signal beyond this point is purely digital until the DAC output cycle of the DASP 24 At the appropriate time the DAC will output the processed left and right signals This action is coordinated with the two output sample and hold circuits 2 3 U9 2 op amps of U3 C39 C40 so that each receives the correct separate signal for stereo output After passing through low pass filters 2 op amps of U4 Misc Resistors amp Capacitors the signals are summed with the output of the dry VCAs note that on older board revisions the signal will pass through the wet VCA U6 first The signals then pass through another filter section U2 etc to the output potentiometer From here they pass through unity gain amps U
36. antly result in a dead ASIC Other than there and in the power supply you really can t do any harm with a scope probe so explore The Curtiss VCAs U5 and possibly U6 are current driven devices so don t expect to see any signals from these chips on a scope Be on the watch for user error i e if a user complains that it won t load from a DataDisk check to be sure that SYSEX ENABLE is turned on Remember to install ALL of the latest revisions before returning the unit This can help prevent many unhappy returns All Trademarks are property of their respective companies Alesis QuadraVerb Service Manual 9 0 Schematics J8 J7 p cer 150 cs 5 1 E mis e p us RIGHT OUTPUT np J12 t E 28 CEM 3981 m NN 7 ER s 52 f in us Rie 13 j RS 1 206 us LEFT OUTPUT a Ku le E 8 i Jil 3 u es 330 3 C48 d 2200 2K Ro a vea cv ioj R48 R47 10
37. ce with the Manual All service or repairs done by you or with reference to the Manual shall be solely your responsibility and Alesis shall have no liability for any such repairs or service work All such service or repairs are performed at the sole risk of the person performing the service or repairs You agree that all such work will be performed in a competent professional and safe manner at all times and to indemnify and fully hold Alesis and its successors and assigns harmless in the event of any failure to so perform Your purchase of the Manual shall be for your own ultimate use and shall not be for purposes of resale or other transfer As the owner of the copyright to the Manual Alesis does not give you the right to copy the Manual and you agree not to copy the Manual without the written authorization of Alesis Alesis has no obligation to provide to you any correction of or supplement to the Manual or any new or superseding version thereof Alesis shall have the right to refuse to sell or otherwise transfer repair parts or materials to you in its sole discretion You shall not use sell or otherwise transfer spare or replacement parts supplied by Alesis to you i to repair or be used in products manufactured for or by third parties or ii to any third parties for any purpose You shall not make any warranties or guarantees with respect to the products of Alesis or the use thereof on behalf of Alesis or in your own name The fo
38. d at as one 56 bit word the format for transmission 1 eight 7 bit words beginning with the most significant bit of the first byte as follows SEVEN OUADRAVERB BYTES 7 5 A4 A2 7 B6 B5 B4 B3 2 E Ge CS EA C362 D7 D6 D5 D4 D3 D2 E E6 F5 E4 E3 F2 F7 F6 F5 FA F3 F2 G7 66 G5 G4 G3 G2 DOF WBN F Q t U Co EL Co C Co TRANSMITTED AS 7 5 4 2 0 7 6 B5 4 B3 B2 BO C7 C6 C5 C4 C3 C2 C1 CO D7 D D5 D2 D1 DO E7 ED E4 E2 El EO F7 F6 F5 4 F2 FO G7 66 G5 G4 G3 G2 G1 GO Dr CX C C CX o OP WN n There are 147 bytes sent for a single data dump which corresponds to 128 bytes of program data There are 14 629 bytes sent for a 100 program dump which corresponds to 12 800 bytes of program data The location of each parameter within a program is shown in the next section When the QuadraVerb receives a data dump message the display reads LOADING MIDI DATA Should the Quadraverb s MIDI input buffer overflow the display will read Alesis QuadraVerb Service Manual 19 MIDI INPUT BUFFER OVERFLOW This message will remain on the display until any button is pressed 03 MIDI Dump Reguest FO 00 00 OE 02 03 program F7 program 0 99 selects individual programs 100 selects the edit buffer gt 100 selects all 100 programs
39. e may not always be possible i e dead power supply bad reset signal corrupt data etc Saving user data may also be accomplished after unit functionality is restored i e power supply or reset line is repaired and prior to further servicing and testing The unit should always be reinitialized power unit up while holding BYPASS and PROG buttons down after changing the EPROM SRAM or any part of the battery backup To perform the QuadraVerb s self diagnostics connect a MIDI cable between MIDI in and MIDI out Power up the unit while holding the BYPASS and CONFIG buttons down The unit will then test ROM RAM Button LEDs MIDI and the clip LED In the event of a ROM RAM or MIDI failure the unit will stop and the display will show ERROR IN COMPONENT 6 0 Adjustments There are no adjustments necessary unless a DAC adjust trimpot has been installed at the time of service The easiest way to adjust the DAC is to use a fast lezlie program with no signal input With the lezlie output turned fully up adjust the trimpot for a minimum noise floor See section 7 0 for installation instructions 7 0 Updates and Revisions Note that these items may not apply to all board revisions Where updates are board revision specific the bold type characters at the beginning of the note indicates applicable board revision designations 7 1 D15 A E Zener diode D15 at bottom right hand corner of board in reset circuit should be a me
40. excessive moisture e The AC power supply plug or cord is damaged The product shows inappropriate change in performance or does not operate normally or e The enclosure of the product has been damaged Alesis QuadraVerb Service Manual 4 General Troubleshooting While this manual assumes that the reader has a fundamental understanding of electronics and basic troubleshooting techniques a review of some of the techniques used by our staff may help Visual Inspection A short visual inspection of the unit under test will often yield results without the need of complex signal analysis burnt or loose components are a dead giveaway Self Test Alesis products that utilize microprocessor control contain built in test software which exercises many of the units primary circuit functions Self test should always be done following any repair to ensure basic functionality Environmental Testing Applying heat and cold heat gun freeze spray will often reveal thermally intermittent components Clock crystals LC s and capacitors are particularly prone to this type of failure Burn in Testing Leaving a unit running overnight often reveals intermittent failures such as capacitors that begin to leak excess current after a significant amount of time Cable Checks Wiggling cables can reveal intermittent failures such as loose cables or poorly soldered headers Remember to check power supply cables a
41. handled through a combination of memory mapped I O see section 4 3 and the 8031 s built in I O ports 4 2 Reset The 8031 reset circuit is perhaps the single most important circuit in the QuadraVerb When this circuit is functioning incorrectly problems ranging from loss of battery backup to a complete lock up of the machine can occur A thorough knowledge of the operation of this circuit will greatly facilitate troubleshooting this unit This circuit uses the differential between raw 10V and regulated 5V to generate the required signals for system reset This is necessary due to fact that the system MUST be in a reset state while powering down otherwise random noise on the 8031 data and address busses could corrupt SRAM data and destroy any hope that the battery backup will work C25 acts as a long time constant to ensure that reset line is enabled long enough for proper system reset D7 acts as a quick discharge path for C25 ensuring that resets will occur even if the unit is turned off and then rapidly back on R16 R60 R58 and D15 work together as a voltage divider to the base of Q3 and is designed so that transistor Q3 will turn on when the raw 10V supply is roughly 7V This is to ensure that reset does not occur until after the 5V regulator is fully functioning i e 5V rail is solid If reset occurs too early noise on the 5V rail can cause data corruption Pull up resistor R59 holds the input of the inverter U25 pins
42. he 8031 While output from the 8031 can be handled simply using memory mapped I O and binary weighted networks analog input to the 8031 is a bit trickier The method used in the QuadraVerb is to examine the time it takes a constantly charging capacitor to reach the level of the input signal The majority of op amp U22 is used to accomplish this We will examine the audio threshold input The principle will also apply to the piezo Z2 value input circuit The process begins with the 8031 temporarily turning on Q2 via mapped I O latch U29 After turning Q2 back off the 8031 begins counting While the 8031 is counting C56 charges through R51 This signal is compared to the incoming rectified analog signal from the LED control circuit by U22 pins 5 6 and 7 When the charge on C56 reaches the level of the input signal U22 pin 7 will change states informing the 8031 via input port P3 2 The 8031 ceases counting and can use the count value as a level value for processing 4 5 DASP 24 ASIC The DASP Digital Audio Signal Processor 24 ASIC Application Specific Integrated Circuit is a complex VLSI IC designed specifically to handle the specialized needs of digital effects processing Obviously a full discussion of this device is beyond the scope of this manual however a brief introduction to the device is definitely in order The DASP 24 contains a SAR Successive Approximation Register a writable control store internal memory for a
43. hould be unplugged from the AC outlet 5 Foreign Objects and Liquids Take care not to allow liguids to spill or objects to fall into any openings of the product 6 Water or Moisture The product should not be used near any water or in moisture 7 Heat Do not place the product near heat sources such as stoves heat registers radiators or other heat producing eguipment 8 Ventilation When installing the product make sure that the product has adeguate ventilation Improperly ventilating the product may cause overheating which may damage the product 9 Mounting The product should only be used with a rack which the manufacturer recommends The combination of the product and rack should be moved carefully Quick movements excessive force or uneven surfaces may overturn the combination which may damage the product and rack combination 10 Cleaning The product should only be cleaned as the manufacturer recommends 11 Service The user should only attempt the limited service or upkeep specifically described in the operating instructions for the user For any other service reguired the product should be taken to an authorized service center as described in the operating instructions 12 Damage to the Product Oualified service personnel should service the unit in certain situations including without limitation when Liquid has spilled or objects have fallen into the product Fn The product is exposed to water or
44. lgorithm storage and a RISC Reduced Instruction Set Computer for use as an Arithmetic Logic Unit Memory management hardware and a variety of control hardware round out the package Some important control signals are outlined below Alesis QuadraVerb Service Manual Signal Pin Function RAS 3 DRAM Row Address Strobe CAS 4 DRAM Column Address Strobe MDE 5 DRAM output enable STB 40 Instructs DASP 24 to accept 8031 DATA CLK 42 24MHz clock from Z1 RST 53 RESET INH 54 Controls sample and hold circuit timing SNHOUT 0 55 SNHOUT 1 56 LSTMSB 57 This signal indicates the last state of the MSB the sign bit in two s complement math This signal in conjunction with R36 R47 R48 and C13 is used to bias the incoming analog signal slightly positive or negative depending on the result of the last DAC cycle i e if the last DAC cycle started off with a negative value LSTMSB will be 1 causing the input to the sample and hold circuit to pull slightly positive On the next cycle the reverse will occur This reduces any audio pop during the attack portion of the input signal and allows for a faster response to small signals ADC 74 A D comparison input OVFLO 75 This signal indicates a math overflow condition and consequently turns on the clip LED circuit WR 84 DRAM write enable 5 0 Test Procedures If possible user data should be saved a DataDisk is recommended prior to any servicing This of cours
45. ll too much high end or muddy too little high end Highs should sound clean up to about 18KHz before rolling off a signal sweep generator is available the frequency response can be specifically compared to the provided Bode plot diagram 9 Use the right input channel Adjust the input level to the QV to about 1Vp p sweeping from 20 2 to 25 2 Observe the filters output at U3 pin 7 Any large deviations from the plot indicate a problem and should be troubleshot R26 R25 R16 33K 27K R16 033uF C43 033uF To U10 20 R42A 7500 To U8 2 I P Filter Schematic De Emphasis Diagram 6 Alesis QuadraVerb Service Manual RIO Remove Li OSolder Mask o R2 46214 47 aD 2 o R28 I CAS Se a CA CAD R27 o R29 o 2 e 6 C50 sko NS Jumpers e e gt O e US Ne Remove IC See Section 7 9 I P Filter Kit Installation Wet VCA Removal Guide Diagram 7 Alesis QuadraVerb Service Manual e e eo eo eo eo o o eo De Emphisis Resistor DAC Adjustment Location Guide Diagram 8
46. m has been modified to decrease the noise present when one of the bands between 250Hz and 16KHz was set to a few dB of cut The duty cycle of the EQ cursor flashing has been changed to improve its visibility Quadraverb Plus first release Too many features to describe Alesis Quadra Verb Service Manual 16 9 5 90 2 01 1 Slight changes to factory programs 11 14 90 2 02 1 If a sampling program was selected when previously a panning program was selected audio triggering and MIDI transposing of the sample would not work properly This is now fixed 2 When in Sample configuration the EO and BYPASS buttons could not be used to enter a new program number while holding the PROG button This is now fixed 3 When selecting a program that was set to the Sample configuration while audio was present would occasionally result noise at the audio output until a sample was recorded This is now fixed 3 10 92 2 03 1 If a MIDI controller was routed to modulate the speed of the chorus an awful sound would occur when the controller was moved This is now fixed Alesis QuadraVerb Service Manual 17 11 0 Quadraverb Plus MIDI Implementation System Exclusive SYSTEM EXCLUSIVE FORMAT The QuadraVerb MIDI System Exclusive message format is as follows FO System exclusive status 00000E Alesis manufacturer id 02 Quadraverb id cc Opcode dd Data F7 End Of Exclusive OPCODES 01 MIDI Editting FO 00 00 OE 02 01 lt function
47. mmended but not necessary Alesis QuadraVerb Service Manual For the purposes of a common orientation we will assume that you are looking at the component side of the board with the front panel facing you Refer to Diagram 7 for individual component orientation Solder one leg of R16 to the left feed through of the original R16 let the other leg stand straight up Solder one leg of RB to the right feed through of the original R16 Scrape the solder mask off of the ground plane under the original R16 then solder one leg of CB to the exposed ground plane again leaving the other leg sticking up Twist the three free standing leads together to form a teepee and solder them together Repeat this procedure with R26 RA and CA R26 on the left RA on the right The ground plane between R26 and R27 is the easiest place to attach CA Solder R42a in parallel with R42 if this is forgotten the de emphasis will not be correct and the unit will sound shrill It is recommended but not absolutely necessary to install R20 200K R44 200K R45 1M and the 250K trimpot R43 When it comes time to adjust the DAC use a fast LEZLIE program and adjust the trimpot for minimum output noise with no input signal and maximum output level Replace the rest of the components per the above value change list To test hook the unit up to a signal source and amplifier Adjust the DAC trimpot Audibly the unit should not sound shri
48. ode D4 a filter capacitor C16 and a transistor resistor diode combination that acts as a steering diode This combination may be missing on older board revisions and must be installed see section 7 0 to prevent data corruption due to a significant difference between and the amplitude of the data buss SRAM standby current should always be checked While the unit is off check the voltage across R61 If the voltage is higher than 80mV specification although a 1 to 20mV range is more normal then a problem exists Usually it indicates a bad or simply wrong SRAM or a short somewhere along the MEM PWR line Note that for a short time Sony 58256 PM high power SRAMS were being installed at the factory and should be replaced with low power versions 58256 LP when found see section 7 0 in order to eliminate excess battery drain We are currently using Hitachi 62256ALPs as replacements CAUTION bDanger of explosion if battery 1 incorrectly replaced Replace only with the same type or eguivalent type recommended by the eguipment manufacturer Battery Manufacturer Tadiran Type TL 5101 Rating 3 6V 3 0 Analog Signal Paths The inputs stereo have their impedances fixed at 1M by R3 and R6 While operating the unit monauraly left input only the input impedance fixed at 500K R3 and R6 in parallel From there the inputs are buffered by U1 A C coupled C1 C2 and passed through a variable input level X10 gain st
49. regoing describes the entire understanding related to sale or transfer of the Manual to you and no other terms shall apply unless in a writing signed by an authorized representative of Alesis Alesis QuadraVerb Service Manual 2 WARNINGS TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE DO NOT EXPOSE THIS PRODUCT TO WATER OR MOISTURE CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN The arrowhead symbol on a lightning flash inside a triangle is intended to alert the user to the presence of un insulated dangerous voltage within the enclosed product which may be of sufficient magnitude to constitute a risk of electric shock to persons The exclamation point inside a triangle is intended to alert the user to the presence of important operating maintenance and servicing instructions in the literature which accompanies the product CAUTION Danger of explosion if battery is incorrectly replaced Replace only with the same type or equivalent type recommended by the equipment manufacturer Battery Manufacturer Tadiran Type TL 5101 Rating 3 6V REPAIR BY ANY PERSON OR ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER WILL VOID THE ALESIS WARRANTY PROVISION OF THIS MANUAL DOES NOT AUTHORIZE THE RECIPIENT TO COMPETE WITH ANY ALESIS DISTRIBUTOR OR AUTHORIZED REPAIR SERVICE CENTER IN THE PROVISION OF REPAIR SERVICES OR TO BE OR MAKE REPAIRS AS AN AUTHORIZED SERVICE CENTER ALL REPAIRS DONE BY ANY ENTITY OTHER THAN AN AUT
50. s well Flexing the PC Board Poor solder joints and broken traces can often be found by pressing the PC Board in various places 7 Tapping Componants Somtimes tapping on a component particularly crystals will cause it to fail 8 Power Down up Turning the unit off and back on rapidly several times may reveal odd reset and or 10 11 12 power supply failures Reset Threshold A Variac variable transformer can be used to check reset threshold levels This can be particularly useful in helping customers with low line problems Compressors Using a compressor limiter is often helpful when attempting to solve low level noise problems as well as assisting with DAC adjustments Sweep Tests Sweep generators are very useful in checking the frequency response envelopes of anti aliasing filters Piggybacking Piggybacking is particularly useful when troubleshooting large sections of logic This is especially true when working with older units Alesis QuadraVerb Service Manual 5 Table of Contents PREEAGE meteo ete eet teat a pitur sa ii READ THIS Lx at c aa aaa a rr ptu e tei o d ii WARNINGS ie o e divae tdi nuit iii SAFETY SUGGESTIONS rei e tete er e ti dii eite eal ian iv General Troubleshooting Rome reed feo ee itr N V 1 0 QuadraVerb General Description U nnne 1 2 0 Power SUpply nuin te edt a beta 1 24 Bat
51. tal zener and NOT a glass zener The glass types have been found to be somewhat unreliable Alesis QuadraVerb Service Manual 7 2 Header Capacitor A E There should be a 1uF cap added between pins 1 and 3 of LED cable header J2 This prevents possible oscillation at power up 7 3 R66 R66 next to opto isolator U30 should be 10K If it is 47K add a 12K or 13K resistor in parallel to make it 10K This decreases the opto isolators input threshold for improved MIDI input performance 7 4 SRAM Supply ii SRAM Supply adjustment See diagrams 4 and 5 This v supplies a solid 5V to the SRAM preventing input data from being higher in amplitude than the supply voltage which can 1N4148 2N3904 cause data corruption 1N914 regulated To SRAM 5V Power New SRAM Supply Circuit 4 7K eee e e U26 2 32 4 Diagram 4 g 7 5 Battery Ground d 1333 Check battery GND connection and resolder T indicate if necessary Cold solder joints can exist there gt o o added componanis resulting in memory loss and crashing Rev D PCB SRAM Kit Check all connector cables are firmly seated Diagram 5 In some cases they can come 1 2 way off 7 5 LCD Contrast Check LCD contrast if contrast is too dark then short D6 7 6 LCD Cable Header Hot glue the LCD cable header to LCD to prevent it from falling off in transit 7 7 Wet VCA Removal A E Software version 1 07 or above lt may
52. tery ato oe ero iia e eed 2 3 0 Ahalog SighaliPath8 s s A e bed 2 34 Antr Aliasing Filters u l oo ro erem e 3 3 2 Successive Approximation U 3 4 0 Digital Signal Paths inte tee E Get et oe nete bt e inn 4 4 1 80C31 Micro Controller Circuit n 4 Avo ReSetsinc ici Ait iene ees ie roe 4 43 Memory Mapped N O vec u aah tiene one dah nied Aa ati eda ates 5 4 4 Analog Input and the 8031 5 AB DASP 24 ASIC isnot o e torte tiet eat din ate 5 5 0 Test Procedures onset ee ere eat 6 6 0 AdjUstimierits ire ee e i re eat 6 7 0 Updates and Revisions E kE o NG e A 6 TADIS a aa etie aee aa a aa 7 7 2 Header Capacitor sa rd a aA 7 FB le steh y rete n a t A 7 TA SEAM SUDDIV ioter iat tian at 7 7 5 Battery Ground sott D etai ot eene tot 7 7 0 Gabl6S x erint d etae ne A 7 To OD Conltast smo lu Det a a a a i aa a aa 7 76 LGD Cable Header iti ED eti oe a aa aa 7 7 7 Wet VOA Removal eiie t e aA 7 7 8 DAC Adjustment Installation 8 7 9 Increasing Output Gail en Ded ote ee LO 8 7 10 QV Filter Kit Installation U u a bae Tana unu aaa nnne 8 8 0 Helpful Hints amp Common Solutions nnne 12 9 0
53. th the Most Significant Bit is taken in turn thus requiring only 16 comparisons to achieve a final value The process begins with the input sample and hold circuit 1 3 of the 4053 U9 is turned on allowing the input sample capacitor C38 to charge or discharge to the level of the current input signal When the switch is turned off the capacitor will hold that level indefinitely 1VIDiv U10 pin 19 20 5uS Div QV Typical DAC output w inactive SAR Diagram 2 U10 pins 19 20 1V Div ne 5uS Div QV Typical DAC Output w active SAR Diagram 3 barring internal leakage At this point the SAR Successive Approximation Register part of the DASP 24 ASIC will take over Starting with the MSB the SAR will set the bit and compare the output of the DAC to the level of the input sample capacitor via comparator U8 The results of the Alesis QuadraVerb Service Manual comparison are stored and the next most significant bit is compared This process continues until a value is found for all 16 bits and the data is ready for further processing by the ASIC note that the value is in two s compliment math In order to view these signals properly on the scope it will be necessary to use an external scope sync use U9 pin 9 as the sync source Diagrams 2 and 3 show the DAC output during a couple of SAR cycles with no input and full input 4 0 Digital Signal Paths Note that later board revisions
54. that caused a volume drop in the mid band EQ if the frequency was 9874Hz amplitude 14 00 dB and bandwidth of 2 55 octaves Default setting for direct signal level changed to 50 from 99 Default setting for reverb level changed to 99 from 50 Fixed bug that caused the bypass level of lezlie programs to be unpredictable Now the bypass level will be the same as the lezlie level All 90 factory programs updated to newer versions Changed bypass level of direct signal so that the master effect level would be used to scale the bypass level if the current program did not have any direct signal in it Changed default mix settings of the last 10 programs 90 99 so that direct level is 50 instead of 99 delay is 50 instead of 40 and reverb is 99 instead of 40 All 90 factory programs updated to newer versions Software version accommodates new hardware in which VCA after DAC is removed This means that the master effects level is controlled by scaling the amplitude of each effect in software instead of changing the VCA level If this software is used with older hardware the VCA will be left full open so that the operation will be the same as with the newer hardware When changing programs with bypass on the dry level will now change with each program to reflect the level of the dry signal in that program When a program is stored the display now reads PROGRAM STORED instead of PROGAM STORED The 11 band graphic EQ algorith
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