From: wbf@aluxpo.att.com Date: Wed, 5 May 93 09:00:46 EDT Original-From: aluxpo!wbf (William Fox) Subject: Re: sh.101 mods. I believe that I found an error in Mark Bower's divide by four circuit. As written, it should just sit there and do nothing. This may just be due to a typo so I won't come down very hard on your digital design; especially since this is the analog list! To make a divide by two flip flop, Q' (inverted output) should feed the D input and the Clock input should be fed from the SYNC CLOCK (or previous stage). Here's a corrected ASCIImatic. ------------------------------------------------------------------- ASCIImatic: 74LS74 D flip flop (numbers = pins on LS74) +-----+ +-----+ SYNC CLOCK CLK1| |Q1 CLK2| |Q2 pulses >----------+ +------------+ +-------> ARPEG. | | _ | | _ D1+-+ +-+Q1 D2+-+ +--+Q2 | | | | | | | | | +-----+ | | +-----+ | | | | | +---------+ +----------+ I removed pin numbers as I'm not sure what they should be. They may have been correct as Mark showed but without a datasheet handy to verify them, I didn't want to post potential misinformation. Cheers and happy soldering! Foxy From markb@tplrd.tpl.oz.au Wed May 5 02:16:05 1993 (5.65c/IDA-1.4.4 for tsines@magnus.acs.ohio-state.edu); Wed, 5 May 1993 16:15:40 +1000 From: markb@tplrd.tpl.oz.au (Mark Bower) Date: Wed, 5 May 93 13:57:08 EST Subject: Re: sh.101 mods. Cc: analogue@magnus.acs.ohio-state.edu This is what I reckon you could do to generate a decent clock signal for the 101 from a SYNC-24 system: Beware: This is only a prototype (I don't have the pinouts of the DIN handy). ------------------------------------------------------------------- ASCIIematic: 74LS74 D flip flop (numbers = pins on LS74) +-----+ +-----+ SYNC CLOCK D1| |Q1 D2| |Q2 pulses >----------+3 5+------------+12 9+-------> ARPEG. | | _ | | _ CLK1+-+2 6+-+Q1 CLK2+-+11 8+--+Q2 | | | | | | | | | +-----+ | | +-----+ | | | | | +---------+ +----------+ SYNC GROUND -----CLOCK CONVERTER GROUND-------------> ARP GROUND/SHLD -------------------------------------------------------------------- Ground on the SYNC should be common to this circuit We are doing a clock divide by 4. the first D flip flop does a divide by 2, the second divides this again to get a total division of 4. If other division types are required (for wierd timings), add more divide stages as required (or extend it to a proper state machine for diviide by 5's or 7's etc - more complex though, but not hard). Of course the 7474 must be powered (TTL) and grounded. Pin 14 is Vcc (5V) and 7 in GND. If the SYNC is NOT TTL, ie. 10V, replace the 74LS74 with a CMOS 74HC74 version and power it at the required levels. The CMOS part can take +15V. Thats all their is to it. It's dead easy to hack together on a bit of verroboard. let me know if anyone tries this el-cheapo clock divider... -Mark Telectronics Pty Ltd <\\ <'\ 15 billion BC: Universal Computer 7 Sirius Rd, Lane Cove >>>=======>-> boots up. Syntax error in bootstrap NSW, Australia 2066 Subject: Re: sh.101 mods. Date: Mon, 3 May 93 13:41:48 EDT Cc: analogue@magnus.acs.ohio-state.edu (Analogue Heaven Synth list.) i would think that it would have to do with changing the LFO timer pot. to be replaced with some type of +/- 5v input for a Pulse signal, but i am not experienced enough to do this. i would think it would be simple, but i am sure it takes some brains (that i am without) anyway, i am interested in the development of this modification because it would make things a lot easier. i have a MIDI to SYNC convertor (msq.100) and it drives my 303, which in turn can drive the external click signal input of the 101 and drive the sequencer or arpeggiator, which sounds really nice. a more tonal 303 without the slides. mark bower gave me a vague description on how to convert a DIN cord into a click signal driver, maybe he could help with the creation of a more concise version, so those of us would not have to use the 303 for the signal and rely solely upon the SYNC signal. as for me, i will try to figure out how i can replace a rate driver on a potentiometer to a 1/8" jack for pulse signals. a square wave to pulse convertor, or vice versa? hmmm.... good luck all. sines -- /\ /\ _________________s i n e w a v e___________________ /\ /\ / \ / \ / todd sines: tsines@magnus.acs.ohio-state.edu \ / \ / \ / \/ \/ 384 e17th ave, columbus, oh 43201 614 299 9529 \/ \/ \ From: wbf@aluxpo.att.com Date: Mon, 3 May 93 10:06:04 EDT Original-From: aluxpo!wbf (William Fox) > metlay said: > > OBMusicCOntent: There is ONE thing about the SH-101 that bugs me: > > no random or noise LFO available for the VCO or VCF when you're > > clocking externally. This is a (minor) drag; is there a way around it? > > YES, get you soldering iron :-) [humpf, humpf] > > Georg. Try this: analogue@magnus.acs.ohio-state.edu > SH-101 Foxy 8-) Date: Mon, 3 May 93 14:53:47 +0200 From: georg@nlp.physik.th-darmstadt.de (Georg Mueller) Subject: Re: A small correction Cc: analogue@magnus.acs.ohio-state.edu metlay said: > OBMusicCOntent: There is ONE thing about the SH-101 that bugs me: > no random or noise LFO available for the VCO or VCF when you're > clocking externally. This is a (minor) drag; is there a way around it? YES, get you soldering iron :-) [humpf, humpf] Georg. Date: Thu, 29 Apr 1993 17:19:42 -0500 From: rej@jerry.sal.wisc.edu (Randy Jones) Subject: Re: A small correction Randy Jones recently said that one could get an SH-101 for $100. This is only true if one is not LOOKING for an SH-101. Sorry Mike, I had no idea you had gotten so detached from your Zen training of long ago. The art of looking without looking... I began looking, and the asking price instantly went up to $300 or thereabouts. However, I would like to thank Stephen Jones for parting with his SH for my sake, and at a relatively reasonable price as well, thereby making me a very happy camper and earning himself 5250 Karma points (TM) redeemable in this or any future incarnation/kalpa. Oh, I see: you're using new techniques. Pardon. I can't imagine taking a soldering iron to this beautiful beastie, no matter WHAT you could add. That's because you haven't heard the Bulgarian Women's choir singing through high Q filter sweeps yet. -Randy From: metlay@netcom.com (metlay) Subject: A small correction Date: Thu, 29 Apr 93 9:43:20 PDT Randy Jones recently said that one could get an SH-101 for $100. This is only true if one is not LOOKING for an SH-101. I began looking, and the asking price instantly went up to $300 or thereabouts. However, I would like to thank Stephen Jones for parting with his SH for my sake, and at a relatively reasonable price as well, thereby making me a very happy camper and earning himself 5250 Karma points (TM) redeemable in this or any future incarnation/kalpa. I can't imagine taking a soldering iron to this beautiful beastie, no matter WHAT you could add. -- mike metlay * atomic city * box 81175 pgh pa 15217-0675 * metlay@netcom.com --------------------------------------------------------------------------- I was looking for you. But I couldn't find you. I was looking for you...... Date: Tue, 27 Apr 1993 18:37:25 -0500 From: rej@jerry.sal.wisc.edu (Randy Jones) Subject: poor little SH-101s. >>Gee, Todd. I think it's about time that you considered buying yourself >>a nice old modular. Sooner or later, that poor SH-101 is going to be nothing >>but a melted heap of acridic analogue goo. Aw, but melted heaps of goo make the best sounds, F/I plays melted heaps of goo right alongside their Buchlas and 2600s. I hear Nicholas Collins is composing a fantasia for melted heaps of goo. God, I'm loving the '90s. At $100 fair and square, SH101s are the second-best classic instrument to carve up. (The best: Magical Musical Thing.) >>>>> >the time where i tried to put the positive phono jacks on the left side of >R109, i ended up with no sound, and the load, play, up, down, up and down, hold >and key transpose lights all came on. i figured, that must not be right so i >took it out and put it on the other side. of course, it worked. Angels hover over you, Todd. You managed to hose something and un-hose it again, no mean feat. I don't know why it didn't work for you with the input before the resistor, but you still do need some resistance in there. Maybe that's where your pot is? >this arbitrary positioning of inputs here and potentiometers there may get me >in trouble, but i think that i will be able to apply a lot of this "stumbled >upon technology" to create machines to my preference.. If the hum gets to be too much, I would recommend that you go battery- powered, and build a Faraday cage into your room. >i can see it now, me building an external jack and pot box for all the >modifications that i make for the sh.101. randy jones never should have told me >those intial mods, nor, should i have ever envied the aphex twin. now i am on >my way, in my mind, to rise above THAT. Don't try and blame those solder burns on me, pal. I'm listening to "Selected Ambient Works" right now, as I have been for the past couple of days virtually non-stop. It's got some pretty cheesy songs, as well as some breathtaking ones. Can't get enough of those pulse waves in Big Dark Rooms... -Randy From tsines@magnus.acs.ohio-state.edu Mon Apr 19 15:50:23 1993 From: s i n e w a v e Subject: Re: Todd's poor little SH-101 Date: Mon, 19 Apr 93 15:49:34 EDT Cc: analogue@magnus.acs.ohio-state.edu (Analogue Heaven Synth list.) james says> Gee, Todd. I think it's about time that you considered buying yourself a nice old modular. Sooner or later, that poor SH-101 is going to be nothing but a melted heap of acridic analogue goo. I'm sure someone could scare up a nice little Moog Series III for you at a reasonable price :-> James >>>> well, i was still interested in your polaris, but my new interest in cheap shit (ie circuits from the radio-shack and that sound synthesis book by terrence thomas...) might just end up having me buy 555 timers and the like. i will probably just spend all my money on that.. (but i still want the polaris!!!) right now, i melted four holes into it with a soldering iron. occupying that space is two phono jacks, one 100K potentiometer, and a hole for an addition that will probably take place tonight. the time where i tried to put the positive phono jacks on the left side of R109, i ended up with no sound, and the load, play, up, down, up and down, hold and key transpose lights all came on. i figured, that must not be right so i took it out and put it on the other side. of course, it worked. this arbitrary positioning of inputs here and potentiometers there may get me in trouble, but i think that i will be able to apply a lot of this "stumbled upon technology" to create machines to my preference.. i can see it now, me building an external jack and pot box for all the modifications that i make for the sh.101. randy jones never should have told me those intial mods, nor, should i have ever envied the aphex twin. now i am on my way, in my mind, to rise above THAT. there was an old sh.101 at the pawn shop, with missing keys and knobs, but i figure... i could do SOMETHING with it. also, the things that radio shack has in their little engineer's mini-notebook are pretty interesting: * 555 (light controlled VCO)--a therimen? * dual supply differentiator (transforms squares into pulses...) * inverting clipper (converts sines to squares) * percussion synthesizer (says bell and drum sounds can be produced) * low and high pass filters * tunable bandpass filters * multi-color organ (i loved these things.. now i get to make one!) * square wave generator * sine wave oscillator * sound effects generator (based on a unijunction transistor) * pulse generator * audio noise generator * adjustable waveform clipper and attenuator * sound effects generator (uses two 555 timers) * tone burst generator (555 timer based) * 3-state tone generator (556 timer based) * stepped tone generator (556 timer based) * gated oscillator * toy organ (haha.,...) * voltage controlled oscillator (uses control voltage inputs) these are from the books: 555 timer circuits, basic semiconductor circuits, optoelectronics circuits, op amp circuits.. all can be had for $5. man, i should have never done this shit. i hope i can still work on music at this rate, go to school (for both sound synthesis and graphic design) and maintain a job. (really, this time...-- ) | | sines <------ -- /\ /\ _________________s i n e w a v e___________________ /\ /\ / \ / \ / todd sines: tsines@magnus.acs.ohio-state.edu \ / \ / \ / \/ \/ 384 e17th ave, columbus, oh 43201 614 299 9529 \/ \/ \ <01GX7005DWAS90NDIS@SKYCAT.USask.CA>; Mon, 19 Apr 1993 11:41:45 CST Date: 19 Apr 1993 11:41:45 -0600 (CST) From: GRAHAME@sask.usask.ca Subject: Re: Todd's poor little SH-101 From: IN%"tsines@magnus.acs.ohio-state.edu" "s i n e w a v e" 19-APR-1993 11:09:52.55 >hey, i was playing with the sh.101 and a soldering iron last night.. man, i >just can't believe myself. >if you connect a jack into the assembly of the 101's housing, and solder a wire >from the same ground trace board (as the other modifications...) to the >negative end of the jack, and then from the postive end of the jack you connect >to the right side of resistor R110. (located right underneath R109.) >this modification makes for a really noisy, yet great frequency mod, and it is >really nice when you pump a chunky 606 through it. Gee, Todd. I think it's about time that you considered buying yourself a nice old modular. Sooner or later, that poor SH-101 is going to be nothing but a melted heap of acridic analogue goo. I'm sure someone could scare up a nice little Moog Series III for you at a reasonable price :-> James -------------------------------------------------------------------------------- ________________________________ / o oooo ooo oooo o o o /\ / oo ooo oo oooo o o o / / J.B. Grahame / _________________________ / / ASPP - Dept. of Psychology / // / // /// // /// // /// / / / / University of Saskatchewan /___ //////////////////////////_/ / Grahame@sask.usask.CA \____\________________________\_\/ From tsines@magnus.acs.ohio-state.edu Thu Apr 8 01:26:39 1993 From: s i n e w a v e Subject: finally, the sh.101 mods. Date: Thu, 8 Apr 93 1:26:26 EDT o n e t h o u s a n d s o r r i e s . . . because this took about forever to get out. sheesh. this is my simplified, yet, working description of what you can do to your sh.101. and have a blast! Voltage Controlled Amplifier/Filter Input: you will need: a screwdriver a soldering iron + solder one 1/4" phone jack some scrap wire 1uF capacitor (not totally necessary) what to do: open up the back of the sh.101 with a screwdriver. the middle screws are of smaller threads and must go back in the same place, so if all else fails, remember these two. bore a hole (i used a soldering iron) into a open spot on the uppper portion of the sh.101--mine is right beside the battery cover to the left. this is where you will want to have your 1/4" phone jack to be stationed...from here you should solder the negative side of your jack to the ground trace of the lower breadboard (scratch off the green coating and solder directly to the copper board.) use some of the scrap wire to connect the positive side of the jack to the capacitor. from the free end of your capacitor, you should solder another wire to connect it to the right hand side of the resistor R109. (are one oh nine...haha) it is located under the "VCF width." you don't HAVE to use the 1uF capacitor, but it suppresses the fat clunk you would get if it wasn't there. my sh.101 is noisy enough as it is... Frequency Modulation input: do the exact same thing as above, yet you should: replace the capacitor with a potentiometer. bore two more holes in the unit (more of that nasty smell!) and place the pot and the jack out near the other jack on the unit. the positive end of the jack should be going through the right lead of the pot, then out through the center lead of the pot, then connect a jumper wire to the left side of the resistor R107, directly below R109. the negative side of the jack should also go to the ground. got it? MORE FUN THINGS with a Roland SH.101: take the output and send it back through the FM input. sounds great when you twiddle the potentiometer as well as the ENV filter in unison. hold.... send a CV output to go back into the gate input, and vice versa. send a CV signal (from a tb.303, perhaps?) into the CV in of the sh.101 and plug the jack in and out, and twiddle it around. it changes voltages and makes it sound like your signal is .... "liquified.." send only a gate signal into the sh.101 and listen (esp with a tb.303... ahh...) my friend andy has two more mods, but i can never get in touch with him. we play with his band this sunday, so maybe we will get in touch. sines -- /\ /\ _________________s i n e w a v e___________________ /\ /\ / \ / \ / todd sines: tsines@magnus.acs.ohio-state.edu \ / \ / \ / \/ \/ 384 e17th ave, columbus, oh 43201 614 299 9529 \/ \/ \ From markb@tplrd.tpl.oz.au Sun Apr 4 23:04:55 1993 (5.65c/IDA-1.4.4 for tsines@magnus.acs.ohio-state.edu); Mon, 5 Apr 1993 13:04:40 +1000 From: markb@tplrd.tpl.oz.au (Mark Bower) Date: Mon, 5 Apr 93 11:14:28 EST Subject: Re: SYNC stuff TO SYNC a roland SH101 to an DIN SYNC-24 line, you need a divide by 4 circuit (a couple of D flip flops will do) and thats all. You use pins 2 and 3 on the DIN (ones CLOCK and ones GROUND - you'll have to check which I can't remember off the top of my head). You could also get tricky and make a selectable divide by adding or bypassing more D-FF stages as required. Some level shifting may be required (useing an op-amp for example) to take the SYNC signal which may be 10 volts on some wierd gear. Mines +5V so I didn't need to shift it - I just put it straight through the D-FFs, then into the 101. I'll try and post some more detailed info when I get time. Cheers, Mark P.S. Looking forward to your 101 posts ;-) From tsines@magnus.acs.ohio-state.edu Mon Apr 19 12:58:22 1993 From: s i n e w a v e Subject: another sh.101 mod. Date: Mon, 19 Apr 93 12:57:02 EDT hey, i was playing with the sh.101 and a soldering iron last night.. man, i just can't believe myself. if you connect a jack into the assembly of the 101's housing, and solder a wire from the same ground trace board (as the other modifications...) to the negative end of the jack, and then from the postive end of the jack you connect to the right side of resistor R110. (located right underneath R109.) this modification makes for a really noisy, yet great frequency mod, and it is really nice when you pump a chunky 606 through it. also, try connecting just a single cv in cable, set your resonance to 10 and then mess with your ENV slider.. raw thin noise. see you. let me know if you enjoy any of the mods. i am glad you all enjoy the list, it makes me very happy to report back to the head of ACS with good news... sines -- /\ /\ _________________s i n e w a v e___________________ /\ /\ / \ / \ / todd sines: tsines@magnus.acs.ohio-state.edu \ / \ / \ / \/ \/ 384 e17th ave, columbus, oh 43201 614 299 9529 \/ \/ \ From tsines@magnus.acs.ohio-state.edu Thu Apr 8 01:26:39 1993 From: s i n e w a v e Subject: finally, the sh.101 mods. Date: Thu, 8 Apr 93 1:26:26 EDT o n e t h o u s a n d s o r r i e s . . . because this took about forever to get out. sheesh. this is my simplified, yet, working description of what you can do to your sh.101. and have a blast! Voltage Controlled Amplifier/Filter Input: you will need: a screwdriver a soldering iron + solder one 1/4" phone jack some scrap wire 1uF capacitor (not totally necessary) what to do: open up the back of the sh.101 with a screwdriver. the middle screws are of smaller threads and must go back in the same place, so if all else fails, remember these two. bore a hole (i used a soldering iron) into a open spot on the uppper portion of the sh.101--mine is right beside the battery cover to the left. this is where you will want to have your 1/4" phone jack to be stationed...from here you should solder the negative side of your jack to the ground trace of the lower breadboard (scratch off the green coating and solder directly to the copper board.) use some of the scrap wire to connect the positive side of the jack to the capacitor. from the free end of your capacitor, you should solder another wire to connect it to the right hand side of the resistor R109. (are one oh nine...haha) it is located under the "VCF width." you don't HAVE to use the 1uF capacitor, but it suppresses the fat clunk you would get if it wasn't there. my sh.101 is noisy enough as it is... Frequency Modulation input: do the exact same thing as above, yet you should: replace the capacitor with a potentiometer. bore two more holes in the unit (more of that nasty smell!) and place the pot and the jack out near the other jack on the unit. the positive end of the jack should be going through the right lead of the pot, then out through the center lead of the pot, then connect a jumper wire to the left side of the resistor R107, directly below R109. the negative side of the jack should also go to the ground. got it? MORE FUN THINGS with a Roland SH.101: take the output and send it back through the FM input. sounds great when you twiddle the potentiometer as well as the ENV filter in unison. hold.... send a CV output to go back into the gate input, and vice versa. send a CV signal (from a tb.303, perhaps?) into the CV in of the sh.101 and plug the jack in and out, and twiddle it around. it changes voltages and makes it sound like your signal is .... "liquified.." send only a gate signal into the sh.101 and listen (esp with a tb.303... ahh...) my friend andy has two more mods, but i can never get in touch with him. we play with his band this sunday, so maybe we will get in touch. sines -- /\ /\ _________________s i n e w a v e___________________ /\ /\ / \ / \ / todd sines: tsines@magnus.acs.ohio-state.edu \ / \ / \ / \/ \/ 384 e17th ave, columbus, oh 43201 614 299 9529 \/ \/ \ Date: Thu, 8 Apr 93 03:38:23 -0400 From: jna@silver.lcs.mit.edu (mail) Subject: Re: finally, the sh.101 mods. Some comments about the SH-101 mods, from a guy who doesn't even own one: SI> ....breadboard (scratch off the green coating and solder SI> directly to the copper board) DON'T DO THIS. Copper oxidies over time, causing RESISTANCE in the circuit. That's why it's sprayed green. Follow the ground plane to a component that is soldered into the board. Melt some of the solder and use this for ground. SI> don't HAVE to use the 1uF capacitor, but it suppresses the SI> fat clunk you would get if it wasn't there. my sh.101 is noisy SI> enough as it is... the 1uF cap acts as a noise filter / decoupling capacitor. Use it. --john (Smail3.1.28.1 #2) id m0ngthj-000MToC; Thu, 8 Apr 93 12:19 MET DST id ; Thu, 8 Apr 93 12:18 MET DST From: ricard@axis.se (Ricard Wolf) Date: Thu, 8 Apr 93 12:18:22 MET DST tsines@magnus.acs.ohio-state.edu Subject: Re: finally, the sh.101 mods. > Some comments about the SH-101 mods, from a guy who doesn't even own one: > > SI> ....breadboard (scratch off the green coating and solder > SI> directly to the copper board) > > DON'T DO THIS. > > Copper oxidies over time, causing RESISTANCE in the circuit. That's why it's > sprayed green. Follow the ground plane to a component that is soldered into I disagree. The green stuff is a solder mask. True, the copper will oxidize after a while, but that's only on the surface. The solder mask reduces the amount of solder needed per board. If you're really worried, tin the area you've scraped away. /Ricard -- Ricard Wolf / | \ / | /- email: ricard@axis.se Axis Communications AB /__| \/ | \__ uucp: axisab.se!ricard S - 223 70 LUND / | /\ | \ Tel: +46 46 19 18 63 SWEDEN / | / \ | \__/ Fax: +46 46 13 61 30 -- "Sweet dreams are made of this" -- From satti002@maroon.tc.umn.eduWed Apr 19 11:07:23 1995 Date: Wed, 19 Apr 1995 06:27:07 -0600 From: Chris Sattinger Subject: Re: HELP WITH SH-101 MODS NEEDED!!! >These are some questions regarding Roland SH-101 mods that are described >in various docuuments up at hyperreal. The problem is that they seem >vague and confusing :( > >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Voltage Controlled Amplifier/Filter Input: > >bore a hole into a open spot on the >uppper portion of the sh.101--mine is right beside the battery >cover to the left. this is where you will want to have your 1/4" >phone jack to be stationed...from here you should solder the >negative side of your jack to the ground trace >connect the positive side of the jack to the 1uF capacitor. >from the free end of your capacitor, you should solder another >wire to connect it to the right hand side >of the resistor R109. it is located under the "VCF width." > >QUESTIONS: > >1) What exactly does this mod do?? Provide an ext. audio in?? Couldn't > one patch a switching jack on the hot side of the Noise fader to do > this?? > yes, ext. audio in. I did this and the level going into it is way to high. Noisy and buzzy. The hot side of the noise fader is probably right next to this spot by r109 anyway. >2) How does one tell what the "right" side of the resistor is?? > Facing it what way?? Based on the reading order of the color codes, > what?? Perhaps someone could tell me what is connected to the "left" > side as a point of reference :) > Having tried it both ways ..... :) Right refers to as the circuit board sits with the main labelling "Roland SH101 Alien Landing Craft etc." facing you like you would be reading it. What a pathetic sentence. Lay the circuit board out with the main lableling all right side up towards you.( the "title" ). Then right is .... uh .... right and left would be the opposite of that. >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Frequency Modulation input: > >do the exact same thing as above, yet you should: replace the >capacitor with a potentiometer. bore two more holes in the unit >and place the pot and the jack outnear the other jack on the unit. >the positive end of the jackshould be going through the right lead of >the pot, then outthrough the center lead of the pot, then connect a jumper wire >to the left side of the resistor R107, directly below R109. the >negative side of the jack should also go to the ground. got it? > >QUESTIONS: > >1) Once again, what is the "left" or "right" side of a resistor?? > >2) As I see it: > > + > | > | > < R107 > ><-----^^^^^^----- > < > | > > Now, does the other side of the pot get sent to ground (aka voltage > divider) ??? > that jives with me. > 3) What value of pot should I use??? > please try various values and then tell me :---) Since several people have decided to do these mods about now, I call for anyone with a bit of technical knowledge to possibly improve upon the audio input. We are thinking the audio input needs resistence to get it steady with that point in the circuit. Signal paths into filters must be low. Chris Sattinger _ MONO ekagra (Probe 12" coming soon), FRAGMENT (Communique double 12 ") reality technician BEAT pHREAK society: we do raves, full scale sensorias, weddings, bar mitzvahs, exorcisms.