Well everyone, here's my much-overdue build report on the Gristelizer. I went into this project finding almost no information on exactly what the heck this thing was supposed to sound like. Obviously I had no clue what the terms VCF and VCA actually meant to my ears. Also, there are precious few sound clips/demos of it out there (here's the best one I could find: http://www.youtube.com/watch?v=37zXCmsGZFk (http://www.youtube.com/watch?v=37zXCmsGZFk)), and there are NO non-experimental sound clips that I could find.
Hopefully this build report will give everyone who is like me a better idea of what is going on with this effect.
Summary:
The Gristleizer is a multi-LFO-shape VCF/VCA modulator. For other noobs, VCF is something like Dano's Optochopto (search it!)--it sounds like a wah with an LFO working the treadle. VCA is a tremolo. That's it and that's all.
Controls:
VCF/VCA Mode Switch--This chooses between VCA and VCF mode.
Volume--It's the volume control...if you need me to describe it, then go somewhere else :)
Bias--for VCA, it's basically the intensity of the effect--from weak and pathetic to clipping the opamps. For VCF, it sets the balance between bass and treble at each end of the LFO sweep. Too much bass distorts the opamps harshly. This control is meant to be a trimmer, but I'd say it's absolutely essential to have outside the box.
Depth--Depth is interesting. For VCA, it's pretty standard for a tremolo depth pot. For VCF, however, the less depth you have, the more you get the bottom end of the LFO sweep--meaning if you have depth at 0, it sounds kinda like a fixed wah you can't really adjust. It's a cool easter egg for some applications.
Speed--The slowest speed setting gives you about a 3-second LFO sweep. We're talkin' SLOW. Dime the speed pot and it's almost to fast to perceive without the Depth all the way up. HUGE speed range.
LFO Shape Switch (Ramp Up, Triangle, Ramp Down, Square)--This chooses the different LFO shapes--pretty self-explanatory...the only thing to note here is that you lose some volume on the Triangle setting, since to jank the LFO into a triangle, it loses some of its depth. This is where the bias pot comes in. If you use Triangle, bias it a little hotter. From my experience with the different shapes, the Triangle setting is the one I keep coming back to--it's the most melodic one in both the VCF and VCA modes.
First Impressions:
Can easily get wild, clips harshly if you bias it hot, can get LOUD, definitely more lo-fi settings than the average bear...erm...effect.
Build Notes:
1. there's an extra pad for the FET on the gm layout--it definitely skips a hole, so check the schematic before you cut the leads. I didn't, and I had to relocate it to the underside of the board. No biggie--I only had one of those :)
2. Everything on the switch wiring layout on the gm Project PDF is correct...except: you need to jump A1 and B1 together.
3. You need a separate power supply--this beast runs on +/-9v. I used the gm bipolar power supply project, based on R.G.'s schematic. Anything that'll get you +/-9v will do. I used a MAX1044 with good results. I also ignored the input jack power switching portion of the project, which is not needed if you're not using a battery.
4. The gm project uses single opamps--I'm sure this could be improved, but I'm cool with my cheapie 741s :icon_cool:
5. Like I mentioned before--move that Bias trimmer to an external pot
6. The other trimmers are to tune the Triangle LFO shape. Mine were pretty good in the middle--this should take minimal adjustment. Keep these as trimmers.
7. Watch your wiring--the LFO can get ticky (even w/ some bleedthrough to the bypassed signal) if you're not careful. The higher you crank the Bias control, the worse it'll get.
8. I added the LFO rate LED mentioned in the comments on the GM site--no ticking problems there--uses a separate NPN transistor to switch an LED based on the LFO. Read it carefully, then draw your schematic from the description. I messed it up the first time...
Pics:
(http://i30.tinypic.com/v6hhna.jpg)
(http://i27.tinypic.com/6zwk2b.jpg)
Sound Clip:
http://www.zshare.net/audio/65463389045694e7/ (http://www.zshare.net/audio/65463389045694e7/)
Chain--Telecaster bridge pickup>Gristleizer>ART tube preamp>Audacity>VST Cab sim
Legend--
Clean Riff
Clean Chord
VCA Ramp Down Riff
VCA Ramp Up Riff
VCA Square Riff
VCA Triangle Riff
VCA Triangle Chord (adjusting from max speed downward)
VCF Ramp Down Riff
VCF Ramp Up Riff
VCF Square Riff
VCF Triangle Riff
VCF Square Chord (adjusting from max speed downward)
Special Thanks:
John Lyons did that gorgeous custom powdercoating job for me--BUY HIS ENCLOSURES. DO IT NOW!
Bluesdevil etched me the PCB--thanks a lot man!
gaussmarkov.net provided the project files for the effect and the power supply.
certain_ant--commenter on the gm project page--provided the flashing rate LED solution
Links:
gm Gristleizer Project: http://gaussmarkov.net/wordpress/circuits/gristleizer/ (http://gaussmarkov.net/wordpress/circuits/gristleizer/)
gm Bipolar 9v Power Supply Project: http://gaussmarkov.net/wordpress/circuits/bipolar-9v-power-supply/ (http://gaussmarkov.net/wordpress/circuits/bipolar-9v-power-supply/)
I think that about covers it. Enjoy!
Awesome. If this was Facebook, I'd give it a Like.
which schematic did you use?
looks really good!!
thanks
Quote from: loss1234 on September 12, 2009, 03:56:04 PM
which schematic did you use?
looks really good!!
thanks
Check out the link to the gaussmarkov project page--you can either just get the schematic, or you can download the entire project pdf :)
Glad you dig it!
Nice build report and nice project !
Thanks for the report! I'm working on one too. I can't listen to your clips right now but I will when I get a chance. Like you, I jumped in not really having any idea what it sounds like. I was just intrigued by the story of the last working original biting the dust.
I'm just waiting till payday to order the pots, rotary switch, and enclosure.
I have 5 pots and 1 trimmer on my version. I used gaussmarkov's schem but did my own layout. I'm in the middle of breadboarding but will probably just build it before I finish the breadboard. I hate breadboarding.
For power, I came up with this:
(http://img.photobucket.com/albums/v337/nosamiam/Picture3.png)
It's the Millenium Bypass and the charge pump. Not verified yet, but it should work.
I must say its EXCELLENT.
I liked (am intrigued by)the sound of VCA down and square,and all the VCF clips except the chord,which is all just IMO,but I could see myself playing that pedal for hours with all those sounds.
BUT that pcb looks so freaky clean and pro,I thought it was fiberboard you drilled and wired underneath until I read it was etched.
I wish I could build all my stuff on PCBs like that.
The enclosure is like everything John does excellent.
Thanx for sharing -its build reports like this that make this forum so useful. :icon_mrgreen:
Quote from: frank_p on September 12, 2009, 04:35:28 PM
Nice build report and nice project !
Thanks!
Quote from: Brymus on September 12, 2009, 05:07:59 PM
I must say its EXCELLENT.
I liked (am intrigued by)the sound of VCA down and square,and all the VCF clips except the chord,which is all just IMO,but I could see myself playing that pedal for hours with all those sounds.
BUT that pcb looks so freaky clean and pro,I thought it was fiberboard you drilled and wired underneath until I read it was etched.
I wish I could build all my stuff on PCBs like that.
The enclosure is like everything John does excellent.
Thanx for sharing -its build reports like this that make this forum so useful. :icon_mrgreen:
No problem--glad to share! :)
In retrospect, I probably would have been better off doing the VCF chord with the Triangle wave--it sounds much better. I was mainly just trying to exhibit the LFO speed range.
With several of the LFO settings at high speed in VCF mode, it sounds like your guitar is blowing a raspberry :) Kinda cool for lead stuff.
Also, one thing my sound clip doesn't illustrate is how great ALL the settings sound going into a distorted amp. Even a hot-biased VCA setting that distorts the opamps in an ugly way sounds awesome, since it acts as a booster on an LFO into your amp.
Cool! Looks good and sounds neat.
I can see how the distorted bits along
witha distorted amp or pedal will get
some great sounds.
Good work!
john
i sure feel dumb for overlooking the schematic!
i thought the link was just for a pcb layout
for those interested in another way of getting +/- rails for this project,
I have been having a blast with
the DC to DC chips sold by mouser.
not super cheap but with one chip and a 5v reg (or a 5v diode)
you can drive over 10 opamps with true +/- 15 volt rails
thanks
Quote from: loss1234 on September 12, 2009, 06:54:28 PM
i sure feel dumb for overlooking the schematic!
i thought the link was just for a pcb layout
for those interested in another way of getting +/- rails for this project,
I have been having a blast with
the DC to DC chips sold by mouser.
not super cheap but with one chip and a 5v reg (or a 5v diode)
you can drive over 10 opamps with true +/- 15 volt rails
thanks
What should I search for, or do you have a part #? This sounds cool!
Finally a real build report for this goddamn thing!!! Many thanks for the superb effort, Josh.
I made my board at the same time, but still need the rotary switch and JFET. I'm actually thinking of making it a non-stomper.... maybe something to set on the amp with controls and switches on the front so I can twiddle the knobs without bending over.
Quote from: bluesdevil on September 12, 2009, 08:15:31 PM
Finally a real build report for this goddamn thing!!! Many thanks for the superb effort, Josh.
I made my board at the same time, but still need the rotary switch and JFET. I'm actually thinking of making it a non-stomper.... maybe something to set on the amp with controls and switches on the front so I can twiddle the knobs without bending over.
That's not a bad idea--I know the one in the youtube video is built that way.
However, that video is a little misleading in some aspects--I thought this thing would self-oscillate. It does not--you have to have some sort of input, so take that into consideration. I could see that setup working well for some crazy feedback manipulation, or you could probably mod it pretty easily to oscillate.
I may end up hooking mine up to my cacophonator to do some cool ambient stuff, just to see what I can come up with.
That looks and sounds awesome! I watched that vid the other day and was intrigued.
Quote from: jacobyjd on September 12, 2009, 08:44:33 PM
Quote from: bluesdevil on September 12, 2009, 08:15:31 PM
Finally a real build report for this goddamn thing!!! Many thanks for the superb effort, Josh.
I made my board at the same time, but still need the rotary switch and JFET. I'm actually thinking of making it a non-stomper.... maybe something to set on the amp with controls and switches on the front so I can twiddle the knobs without bending over.
That's not a bad idea--I know the one in the youtube video is built that way.
However, that video is a little misleading in some aspects--I thought this thing would self-oscillate. It does not--you have to have some sort of input, so take that into consideration. I could see that setup working well for some crazy feedback manipulation, or you could probably mod it pretty easily to oscillate.
I may end up hooking mine up to my cacophonator to do some cool ambient stuff, just to see what I can come up with.
Yep, that's what I was thinking. Put something in front of it that self-oscillates.
Seems like feedback from the output of IC5 to its + input would make it oscillate, no? Add a pot to control amount of feedback...
Nice. Elvis in Hawaii.
How about grabbing that bias knob and showing us Elvis at Sun.
Quote from: Dan N on September 12, 2009, 11:07:55 PM
Nice. Elvis in Hawaii.
How about grabbing that bias knob and showing us Elvis at Sun.
Not sure what you mean by that...
Quote from: nosamiam on September 12, 2009, 10:53:03 PM
Quote from: jacobyjd on September 12, 2009, 08:44:33 PM
Quote from: bluesdevil on September 12, 2009, 08:15:31 PM
Finally a real build report for this goddamn thing!!! Many thanks for the superb effort, Josh.
I made my board at the same time, but still need the rotary switch and JFET. I'm actually thinking of making it a non-stomper.... maybe something to set on the amp with controls and switches on the front so I can twiddle the knobs without bending over.
That's not a bad idea--I know the one in the youtube video is built that way.
However, that video is a little misleading in some aspects--I thought this thing would self-oscillate. It does not--you have to have some sort of input, so take that into consideration. I could see that setup working well for some crazy feedback manipulation, or you could probably mod it pretty easily to oscillate.
I may end up hooking mine up to my cacophonator to do some cool ambient stuff, just to see what I can come up with.
Yep, that's what I was thinking. Put something in front of it that self-oscillates.
Josh misunderstood my comment. I'm going to put mine last in the effects chain and just sit it on top of my amp to make twiddling with the controls while playing easier.
Having it self oscillate to make a self contained noise unit isn't a bad idea either, though!!
Sounds great! The VCF stuff reminds me of the old leslie simulator circuit, from which I think the original Phozer was based on. Psychedelic, man... :icon_wink:
Quote from: bluesdevil on September 13, 2009, 12:00:18 AM
Quote from: nosamiam on September 12, 2009, 10:53:03 PM
Quote from: jacobyjd on September 12, 2009, 08:44:33 PM
Quote from: bluesdevil on September 12, 2009, 08:15:31 PM
Finally a real build report for this goddamn thing!!! Many thanks for the superb effort, Josh.
I made my board at the same time, but still need the rotary switch and JFET. I'm actually thinking of making it a non-stomper.... maybe something to set on the amp with controls and switches on the front so I can twiddle the knobs without bending over.
That's not a bad idea--I know the one in the youtube video is built that way.
However, that video is a little misleading in some aspects--I thought this thing would self-oscillate. It does not--you have to have some sort of input, so take that into consideration. I could see that setup working well for some crazy feedback manipulation, or you could probably mod it pretty easily to oscillate.
I may end up hooking mine up to my cacophonator to do some cool ambient stuff, just to see what I can come up with.
Yep, that's what I was thinking. Put something in front of it that self-oscillates.
Josh misunderstood my comment. I'm going to put mine last in the effects chain and just sit it on top of my amp to make twiddling with the controls while playing easier.
Having it self oscillate to make a self contained noise unit isn't a bad idea either, though!!
No problem--that's what I figured. I just wanted to clear up that this isn't a noisemaker--based on the info in various places on the net, I was under the impression that it would self-oscillate. YMMV though.
Quote from: DougH on September 14, 2009, 08:27:31 AM
Sounds great! The VCF stuff reminds me of the old leslie simulator circuit, from which I think the original Phozer was based on. Psychedelic, man... :icon_wink:
I know what you mean--the VCF can get pretty wild.
I know that circuit ! - Its from an old english mag. Never quite got it happening , I'll have to dig it out again.
A lot like the sort of thing that Lovetone would make.
HERE IS THE dc TO dc converter part number and mouser code
Mouser #: 580-NMH0515SC
Mfr. #: NMH0515SC
Desc.: Low Power (1.5W-9W) DC-DC Converters - SIP 2W DUAL OUT 5-15V Dual Output
thanks
Anyone try this guy with ICs other than 741s? Like a TL071? Just wondering because I'm going to be starting my build next week.
Quote from: thedefog on September 15, 2009, 10:50:42 AM
Anyone try this guy with ICs other than 741s? Like a TL071? Just wondering because I'm going to be starting my build next week.
TL071s should work fine--AFAIK, any single opamp will do for the GM project layout--just make sure your pinouts match! If you're doing your own layout, any opamps will do.
Isn't the 741 supposed to be pretty junky? Do you guys think that's kind of the point?
I probably won't build this, but I might do a layout for dual opamps if anyone's interested.
Quote from: Taylor on September 15, 2009, 04:55:55 PM
Isn't the 741 supposed to be pretty junky? Do you guys think that's kind of the point?
I probably won't build this, but I might do a layout for dual opamps if anyone's interested.
Well, the effect is definitely intended to be more of a lo-fi thing...mine doesn't come off that way in a lot of settings though.
In all reality, when we're talking the world of guitars and amps, the negative characteristics of the 741 don't really make themselves apparent to me. If you think about it, there are a lot of circuits that use 741s to good end.
The only real advantage I could think of (besides marginally better fidelity, I suppose) is space saving, and for that, a quad opamp paired with a single would probably serve better.
Yep, now that I see there are 5 singles, a quad plus a single would be best. If there was enough interest, I could even do a fancy double-sided Gerber layout and we could all go in on the board manufacturing, but something tells me there wouldn't be enough takers.
I just found a free CAD program for Mac, so I'm kind of itching to use it on something.
Quote from: Taylor on September 15, 2009, 05:24:49 PM
Yep, now that I see there are 5 singles, a quad plus a single would be best. If there was enough interest, I could even do a fancy double-sided Gerber layout and we could all go in on the board manufacturing, but something tells me there wouldn't be enough takers.
I just found a free CAD program for Mac, so I'm kind of itching to use it on something.
I'd be down for at least 3-4
Quote from: Taylor on September 15, 2009, 05:24:49 PM
Yep, now that I see there are 5 singles, a quad plus a single would be best.
No! Don't run the audio in the same chip as the lfo! I speak from experience :icon_redface:.
Found it !
PRACTICAL ELECTRONICS July 1975.
So the good old 741 was probably state of the art.
Taylor- If you could re-model it you would probably make a lot of people pretty happy .
The veroboard layout in the mag. is 26 lines of 43 holes.
Quote from: Dan N on September 15, 2009, 08:04:52 PM
No! Don't run the audio in the same chip as the lfo! I speak from experience :icon_redface:.
Perhaps IC1, 2, and 3 could be in a quad and IC4 and 5 could be a dual? 2 ICs instead of 5 is a decent improvement, right?
Although LFO ticking seems more inkeeping with the industrial background of this effect... :icon_wink:
I like board-mounted pots, so I'll probably do those, because it wouldn't preclude offboard pots if that's what you like.
Started a thread about this so as to not derail this build report thread too much:
http://www.diystompboxes.com/smfforum/index.php?topic=79078.0
AWESOME REPORT!
I've been working on one of these for a few months, due to time. Could you sketch up the rate led circuit for me? i checked the GM notes and don't understand the "led plus load to the collector" part.
Again, fantastic report, i'm super stoked to get mine up and running.
Quote from: deathfaces on October 22, 2009, 05:33:37 PM
AWESOME REPORT!
I've been working on one of these for a few months, due to time. Could you sketch up the rate led circuit for me? i checked the GM notes and don't understand the "led plus load to the collector" part.
Again, fantastic report, i'm super stoked to get mine up and running.
This should do it for you: http://www.diystompboxes.com/smfforum/index.php?topic=79078.msg657184#msg657184 (http://www.diystompboxes.com/smfforum/index.php?topic=79078.msg657184#msg657184)
The base of the transistor goes to the LFO, as stated...which is pin 6 of IC....um...1(? Don't hold me to it ) on the Gaussmarkov project site. :)
Hey guys,
I finally got the money to get the remaining part order for my build (yes I'm that poor). I just finished populating up the pcb last night, so now I just need to do some wiring and I'll fire it up and let you know how it went, along with some audio/pictures.
I ended up using the 741s, as I had lots of them and they're super cheap. Didn't socket them, so I can't swap out to try others (sockets are more expensive than the chips!).
It may be a few days or so... Plus I have to figure a work-around for the selector switch. I didn't plan on using the standard rotary, for cost reasons (and the fact that I have tons of normal switches).
Ray Wilson over at Music From Outer Space has a nice solution for 4 waveform selection that he uses in his Sound Lab Ultimate. It's a combination of a 2-way selector switch and a 3-way, where the two way selects between a square & the lower 3 way switch with triangle - ramp up - ramp down. See in this picture of my build here: http://www.flickr.com/photos/33480248@N05/3657649691/sizes/l/in/set-72157620494189044/
Quote from: jacobyjd on September 12, 2009, 02:44:21 PM
1. there's an extra pad for the FET on the gm layout--it definitely skips a hole, so check the schematic before you cut the leads. I didn't, and I had to relocate it to the underside of the board. No biggie--I only had one of those :)
THANK YOU!
This solved the problems with mine not working, I think. It's definitely sounding much better!
Now to finally think about an enclosure for it...
Fired this up last night and it makes sound, but not the right sound. Unless bias is cranked, it sounds like a clean guitar signal and the LFO in parrellel, lots of ticking, almost like an oscillator because depth knob adjusts the amount of tick. Ticks even without input. Shape and offset trimmers appear to do nothing.
"7. Watch your wiring--the LFO can get ticky (even w/ some bleedthrough to the bypassed signal) if you're not careful. The higher you crank the Bias control, the worse it'll get. " = What do you mean by this? Watch wiring how, because my wiring appears sound, but still ticksssssssss
Advice?
Quote from: deathfaces on November 04, 2009, 12:22:50 PM
Fired this up last night and it makes sound, but not the right sound. Unless bias is cranked, it sounds like a clean guitar signal and the LFO in parrellel, lots of ticking, almost like an oscillator because depth knob adjusts the amount of tick. Ticks even without input. Shape and offset trimmers appear to do nothing.
"7. Watch your wiring--the LFO can get ticky (even w/ some bleedthrough to the bypassed signal) if you're not careful. The higher you crank the Bias control, the worse it'll get. " = What do you mean by this? Watch wiring how, because my wiring appears sound, but still ticksssssssss
Advice?
Mainly, I'd suggest keeping all connections to the rotary switch/depth/bias/speed controls away from any signal connections. If you're not hearing much effect on the signal, something is wrong--the effect should be very obvious with the bias cranked. Is your power supply regulated? Make sure you're getting the proper +/-9v to all necessary locations.
The shape and offset trimmers are only to fine-tune the sine wave LFO.
It sounds like your problem might be with the rotary switch wiring--re-check that, because your LFO might not be hitting the audio signal at all :)
It sounds like the LFO isnt hitting the signal at all, like you suggested. I checked the wiring in the rotary and on the stomp, and the signal appears to be heading in the right directions. I'm using a charge pump with a ibanez 9v adapter so it should be pretty good. Pretty stuck here...
Here's some photos, maybe you can see something i cant.
High-RES: http://www.mediafire.com/?ng4fmm1ax0c (http://www.mediafire.com/?ng4fmm1ax0c)
(http://i35.photobucket.com/albums/d165/matthewsochocki/gristleizer/1.jpg)
(http://i35.photobucket.com/albums/d165/matthewsochocki/gristleizer/2.jpg)
(http://i35.photobucket.com/albums/d165/matthewsochocki/gristleizer/3.jpg)
(http://i35.photobucket.com/albums/d165/matthewsochocki/gristleizer/4.jpg)
(http://i37.tinypic.com/mts6k1.jpg)
I think you've almost got it--if you jumper the two highlighted pins together, you should have it :) Don't hold me to it though, because I can't see where exactly all those wires go in the pics :)
nope, no dice. i think that connection was wrong on the original gaussmarkov pdf and was corrected. i used the file marked layout on the right side of the gristleizer page. i thought this was a corrected version from the comments on the blog and the schematic shows a4 and b1 connected as opposed to a4 and b4 . i traced back the wires and everything appears to be connected appropriately, but still no meshed effect.
this layout:
http://gaussmarkov.net/layouts/gristle/gristle-perf.png (http://gaussmarkov.net/layouts/gristle/gristle-perf.png)
Have you got a closeup of your switch?
Hey Guys,
I just finished my build tonight, but no dice. I checked my soldering, components, and switch wiring according to the PDF and it all looks good. I'm using a 2 pole 6 way switch with two of the positions unused. I get a ticking from the LFO and the signal passes through weakly. When the DPDT is thrown again, I get nothing at all. So the VCA section of it seems to at least pass a signal, but the VCF is no good.
Speed pot is the only thing that seems to affect anything. I'm going to trace the signal path and see where it's stopping.
Quote from: thedefog on November 04, 2009, 09:21:17 PM
Hey Guys,
I just finished my build tonight, but no dice. I checked my soldering, components, and switch wiring according to the PDF and it all looks good. I'm using a 2 pole 6 way switch with two of the positions unused. I get a ticking from the LFO and the signal passes through weakly. When the DPDT is thrown again, I get nothing at all. So the VCA section of it seems to at least pass a signal, but the VCF is no good.
Speed pot is the only thing that seems to affect anything. I'm going to trace the signal path and see where it's stopping.
OK I seriously need to work on my reading skills. A1 & B1 were not jumpered, as shown in the build report, and my FET was not skipping the hole to go to ground. I'm sure that's all that is wrong. Hopefully my FET wasn't fried being wired to the -9vdc.
So I just noticed that A1 and B1 on the main GM project page actually aren't. In the layout files, it's A4 and B1. If I get a chance in the next few days, I'll open mine up and confirm what I've got to settle this :)
Quote from: jacobyjd on November 04, 2009, 09:48:18 PM
So I just noticed that A1 and B1 on the main GM project page actually aren't. In the layout files, it's A4 and B1. If I get a chance in the next few days, I'll open mine up and confirm what I've got to settle this :)
That'd be awesome. I'm out of town until Sunday night so no rush. Before i go tomorrow i'll get some readings off the IC's if you want to really go crazy while you've got yours open.
@thedefog that extra trace is really messing everyone up. it got me too initially.
It is A4 & B1, as I got nothing from the square wave selection of the switch until I wired it this way. Now all the switch positions are doing what they are supposed to. The only issue I seem to have is that the Triangle waveform section is MUCH louder than the others. I dunno if that's the way it is supposed to be, as I have my SH-101 plugged into it and not a guitar so I've got an obvious impedence mismatch for the circuit (even though I've got it turned way down).
I'm gonna post pictures & sound clips on this shortly. Thanks guys for all of your help!
Interesting--my triangle position is quieter--it never reaches the top of the waveform--it's nothing that I haven't been able to overcome in a live situation :)
Here's what I'm getting. This is with a standard ibanez 9volt supply (same as boss) and GGG bipolar charge pump. I'll probably send a gift to whoever helps me crack this case
IC1
1: -8.43
2: 0
3: 0
4: -8.44
5: -8.43
6: -1.58
7: 8.7
8: 0
IC2
1: -8.44
2: 0
3: -2.45
4: -8.44
5: -8.44
6: -6.3
7: 8.69
8: 0
IC3
1: -8.43
2: 0
3: 0
4: -8.44
5: -8.43
6: -1.69
7: 0
8: 0
IC4
1: -8.43
2: -0
3: -0
4: -8.44
5: -8.43
6: -.05
7: 8.69
8: 0
IC5
1: -8.43
2: 0
3: 0
4: -8.44
5: -8.43
6: .08
7: 8.69
8: 0
D1
Anode: -6.31
Cathode: .01
D2
Anode: .63
Cathode: 1.12
TR1
c: .46
b: -.18
e: .39
TR2
d: 0
g: .63
s: 0
it also occurs to me that i originally had the -9v and +9v reversed. could this have screwed something up? everything seems to be reading voltages (although, i have no idea if correct). That last tranny seems suspicious though
IC3 also seems suspicious with 0 at pin 7, which should be v+
lm741 pinout: (http://www.national.com/images/pf/LM741/00934103.pdf)
Also, I'll create a new post for this if you'd like, i dont want to hijack your thread, though if we get this worked out, it'll be good for the next guy to have it all in one place.
I agree--it's good to have a debug attached to this thread--feel free to keep it going here.
Re: mixing up +/-9v...eh...I don't know enough about all this craziness to tell you for sure that this is the reason your circuit is borked...if you still hear the LFO ticking, then you might be ok, but AFAIK, reverse voltage isn't a good problem to have.
The thing that jumped out at me on those voltages (besides the transistors being wacked out) is that there should be some sort of reference voltage going to the opamp--your voltages look consistent, and I'm guessing vref all goes to the same place. Check that first.
I agree, it appears that something is happening, so its not a total failure. The transistors do seem weird. I agree about reverse voltage, i goofed when i was modifying the pcb, but only fired it up for a few moments before i realized i goofed (though i do realize this is more than enough time to fry every ic - which i have extra of, should it come to replacing everything)
noob question. reference voltage means the voltage coming from the adapter i'm using the to power the circuit? if so, it's putting out 8.85v. I'm afraid i dont know what exactly vref is, and couldnt find a clear answer in the forum.
pin 7 should be the v+ to the opamps, so i'd assume thats the culprit on ic3. but when i probe pin 7 of ic3, i get sound - like a buzz, what i assume is the triangle wave.
here's the pinout of the max1044 (charge pump is just below satan in the pictures):
Max1044
1: 8.71
2: 4.29
3: 0
4: -4.27
5: -8.45
6: 4.24
7: 6.42
8: 8.7
Since yours is pretty much the only functional gristleizer the diy community has to offer, would you cross-reference the voltages? i'm ready to start replacing, but dont want to get panicked and premature.
sorry--I think I was getting vref mixed up with Vbias. I'm a noob at the technical side of opamps too :(
hmm, how do i check vbias? Looks like the next step is tracing the audio path, which i've always been crappy at.
also, i meant i get a buzz out of IC3's output, pin 6, when i used an audio probe.
I'm pretty sure Vb should be +4.5VDC
Checked the schematic and i'm not sure at what point to check Vb, suggestion?
I have a gut feeling this has something to do with TR2 because that looks like the point on the schematic that links the guitar signal to the LFO. The original Gwinn file indicates this is supposed to act as an attenuator, but i'm still decoding what exactly that means.
Here's the original RG Keen file: http://www.synthdiy.com/files/2005/gep.pdf (http://www.synthdiy.com/files/2005/gep.pdf)
This may be one of those situations where an audio probe would work better than checking voltages to figure out where and when the signal craps out on you.
I'm debugging mine as well. I finally got to check mine out with a guitar instead of my synth, and it still sounds pretty nasty in a bad way. It's pretty distorted. I suspect I have a wrong resistor value somewhere in there. It's a shame I'm color blind because it makes reading resistors that are already on the board impossible.
Hi all! Just joined diy stompboxes as I am building the Gristleizer too. I have a few problems with the wiring of the rotary pot. One of the positions appears to do nothing at all to the sound. Just wondering if a consensus has been reached as to the correct diagram of what to be wired where. There appears to be conflicting diagrams about A1 B1, A4 B1 etc. Anyone out there able to clarify this for us wannabe TG freaks?
Quote from: -minus on November 18, 2009, 12:41:55 AM
Hi all! Just joined diy stompboxes as I am building the Gristleizer too. I have a few problems with the wiring of the rotary pot. One of the positions appears to do nothing at all to the sound. Just wondering if a consensus has been reached as to the correct diagram of what to be wired where. There appears to be conflicting diagrams about A1 B1, A4 B1 etc. Anyone out there able to clarify this for us wannabe TG freaks?
Hey there, and welcome to the forum!
A4 to B1 solved that issue for me. The square wave function won't work (last position on the rotary) if this jumper connection isn't made. Good luck!
Quote from: thedefog on November 18, 2009, 11:20:18 PM
Quote from: -minus on November 18, 2009, 12:41:55 AM
Hi all! Just joined diy stompboxes as I am building the Gristleizer too. I have a few problems with the wiring of the rotary pot. One of the positions appears to do nothing at all to the sound. Just wondering if a consensus has been reached as to the correct diagram of what to be wired where. There appears to be conflicting diagrams about A1 B1, A4 B1 etc. Anyone out there able to clarify this for us wannabe TG freaks?
Hey there, and welcome to the forum!
A4 to B1 solved that issue for me. The square wave function won't work (last position on the rotary) if this jumper connection isn't made. Good luck!
Nevermind what I wrote there. I solve my problem, as well as yours.
http://gaussmarkov.net/layouts/gristle/gristle-perf.png
Just follow the wiring diagram on the gaussmarkov page. Ignore the PDF wiring and you should be fine. I now have no issues with the distorting volume or anything anymore with mine following this wiring.
Nevermind what I wrote there. I solve my problem, as well as yours.
http://gaussmarkov.net/layouts/gristle/gristle-perf.png
Just follow the wiring diagram on the gaussmarkov page. Ignore the PDF wiring and you should be fine. I now have no issues with the distorting volume or anything anymore with mine following this wiring.
Thanks thedefog! I have rewired the rotary pot. Had some success...
Now I know this is not correct as following the layout, but by wiring A3 and A4 together, as well as A4 to B1, I am getting some quite 'throbbing' sounds on this setting. All my pots are external at this stage. Got a trim pot for SHAPE today. This pot seems to do nothing in my mind. However, with my 'bent' A3 to A4 mod, using the OFFSET and SPEED pot, I am getting some very nice undulating sounds... if you like that type of droney thing. I'm plugging an Atari Punk Console into it to get a single tone.
I'm almost thinking about leaving it as this, as this hack seems to be the mode I keep coming back to. And no, I'm not sure why this is. I have little experience with this DIY stuff and am a solder-by-numbers person at this early stage.
I wouldn't mind slowing it down further though. Perhaps increasing a cap value somewhere?
Quote from: -minus on November 19, 2009, 06:52:45 AM
Nevermind what I wrote there. I solve my problem, as well as yours.
http://gaussmarkov.net/layouts/gristle/gristle-perf.png
Just follow the wiring diagram on the gaussmarkov page. Ignore the PDF wiring and you should be fine. I now have no issues with the distorting volume or anything anymore with mine following this wiring.
Thanks thedefog! I have rewired the rotary pot. Had some success...
Now I know this is not correct as following the layout, but by wiring A3 and A4 together, as well as A4 to B1, I am getting some quite 'throbbing' sounds on this setting. All my pots are external at this stage. Got a trim pot for SHAPE today. This pot seems to do nothing in my mind. However, with my 'bent' A3 to A4 mod, using the OFFSET and SPEED pot, I am getting some very nice undulating sounds... if you like that type of droney thing. I'm plugging an Atari Punk Console into it to get a single tone.
I'm almost thinking about leaving it as this, as this hack seems to be the mode I keep coming back to. And no, I'm not sure why this is. I have little experience with this DIY stuff and am a solder-by-numbers person at this early stage.
I wouldn't mind slowing it down further though. Perhaps increasing a cap value somewhere?
That's odd that you have a difference by wiring both of them together. I didn't notice any difference when A3-A4 were jumpered, so I disconnected them.
On another note, I experimented more (during daytime hours when I could actually turn my amp up) and still noticed the distortion in the circuit. I'm guessing the 741 buffer stage is amplifying it a bit too much for a guitar. This is even with the input impedance mod, changing R19 to 1M, along with increasing R21 to 1M and R20 to 100K. I also changed C7 to a .33uf cap to allow a bit more low end through the input.
I am guessing my R22 value is off, or TR2 was damaged due to it being connected to the negative 9v initially. I'm going to check these and post an update.
And one more thing, I'm getting a bit of noise when turning the pot for volume. Is a .068uf as a coupling cap too low a value to keep the DC voltage from the pot? I'm going to experiment with that as well. Any insight would be valuable here.
Hmmmm... Cant really help with coupling cap query. Too much of a novice really. This seems to be a tricky circuit for some reason. I like Throbbing Gristle, but apart from saying "Throbbing Gristle" every time someone asks what that box is, this has been a bit of a let down. I don't play guitar so I probably have different criteria as to what sounds great.
I'm thinking of mucking around with this board some more and taking it away from its initial intention. Might try substituting some resistor and capacitor values here and there and see what happens. I didn't notice anything significant from the triangle selection. Ramp and saw seem to work, although it sounds very subtle. Bit of a legendary effect from a legendary group, but not sure if it has been worth the bother.
I'm still debugging mine. Hoping for a breakthrough soon.
I tried higher R22 values, as well as replacing the transistor as I had mentioned before, but it didn't remedy the problem. Increasing R22 causes the effect to not work properly, due to it being designed to have a high gain output. I think the best solution to this would be to use an opamp with a lower gain than the 741 for the input buffer stage. Perhaps something with a 10x buffer factor rather than like 100x would tame it, but then a few other changes would probably have to be made in order to make the circuit behave correctly. I'm going to experiment a bit with this and post what I find.
I did some probing and found that the signal went into ic4 just fine, but then it was mixed with a buzzing sound on its way out. Could this be a bad ic? the lfo part of the circuit sounds like what i'll assume it is supposed to sound like (for the time being). When i probed tr2 i got the buzzing from ic4, but no lfo sounds. advice? thanks
Hi,
I was thinking about building a Gristleizer, but using it for more noise-based stuff. Are there any more thoughts on getting it to self-oscilate?
Ie. ~4:05 in this video http://www.youtube.com/watch?v=gV597br-oq8&feature=related
Quote from: deathfaces on November 27, 2009, 03:05:34 PM
I did some probing and found that the signal went into ic4 just fine, but then it was mixed with a buzzing sound on its way out. Could this be a bad ic? the lfo part of the circuit sounds like what i'll assume it is supposed to sound like (for the time being). When i probed tr2 i got the buzzing from ic4, but no lfo sounds. advice? thanks
I doubt the IC went bad. 741s are pretty hard to fry. I have yet to do so in 10 years of doing this stuff, nor have I replaced a bad one anywhere on anything I've repaired.
You are building yours from the PCB board layout and not perf or vero, correct? Is the Buzzing regardless of whether you play a note? And is it like a ground noise buzz, or a higher pitched thing? You could just be hearing the LFO with the speed cranked up all the way.
Quote from: grinnin on December 06, 2009, 05:51:01 PM
Hi,
I was thinking about building a Gristleizer, but using it for more noise-based stuff. Are there any more thoughts on getting it to self-oscilate?
Ie. ~4:05 in this video http://www.youtube.com/watch?v=gV597br-oq8&feature=related
Hey there,
What Taylor wrote works:
"Seems like feedback from the output of IC5 to its + input would make it oscillate, no? Add a pot to control amount of feedback..."
I wired it up, but found it not to be so useful for me. But different strokes...
i got it working well enough, i replaced the ic's and trannies. the bias pot only seems to do anything when its turned to at least 6 o clock, so theres something funny there. the clock noise just seems to be part of the circuit, judging by jacobs demos, or maybe mine isnt gating enough between the oscillator and input signal. either or, it'll do enough for me to have fun with it, so on to something new.
Quote from: deathfaces on December 19, 2009, 07:56:48 PM
i got it working well enough, i replaced the ic's and trannies. the bias pot only seems to do anything when its turned to at least 6 o clock, so theres something funny there. the clock noise just seems to be part of the circuit, judging by jacobs demos, or maybe mine isnt gating enough between the oscillator and input signal. either or, it'll do enough for me to have fun with it, so on to something new.
I notice minimal clock noise in my build. I only really hear it on the square wave output, and that is just part of the circuit. If you hear it in different modes, there may yet be something off in your build. Post some samples of it on here and maybe I'll be able to help you out some.
Hi everybody !
I have this pedal kit but not possible to find a schematic to solder : DC, 3PDT, Jacks and PCB together... :( I tried different ways and everytime it didn't work.
Can you help me please.
So I join a picture of my current stuf :
(https://s15.postimg.cc/a9seb4yav/Sans_titre_1.png) (https://postimg.cc/image/a9seb4yav/)
Have a nice day, Anthony.
I've only had one coffee this morning (so not truly awake yet...), but it looks to me like you're shorting the power when the switch is "up"? (I've not got as far as working out what's going on when it's "down".) Go to Tonepad and check out their wiring diagrams (http://www.tonepad.com/getFile.asp?id=76). There are other schemes out there, but I've been using #3 and #5 from day one with no problems.