Anybody build their Gristleizer yet, comments on it?

[Taylor]

I accidentally dropped a solder blob in one of the small (unused?) holes on the board. Problem or not?

Not a problem, doesn't matter.

[hoso]

Ok, so I finished the thing. And for some reason I got + and - wrong so I probably destroyed the whole thing! I'm the worst Gristleizer builder ever.

[1878]

I built this a week or two ago and it fired up first time. I fitted it into the enclosure last night and now it doesn't work This is what I've found so far...

The LED flashes as it should. Speeds up/slows down etc.
The background noise gets louder as the volume is turned up.
Clean signal in bypass.

Anyone know of any points where I may have blown something etc ?? Also, does anyone have any voltages before I get my meter fired up ??

Thanks.

[Taylor]

It's unlikely you blew anything just from putting it in the box. More likely something is shorting out to the enclosure. Check to see if any part of the circuit is contacting the enclosure.

[1878]

I took it out of the box, still nothing. I've replaced all the transistors and IC's (I love sockets) and still nothing. I checked them all over with my meter and everything seems fine, including some variable readings on the TL074. I've replaced the 3PDT with a DPDT I had lying around but all to no avail.

The LED flashes as it should. Speeds up/slows down etc.
The background noise gets louder as the volume is turned up.
Clean signal in bypass.

The above still stands, but I'd wired the pots 321 instead of 123 which has now been remedied.

I am seriously confused, and it's made worse by the fact that it was working perfectly yesterday 

[Taylor]

Ok, if you're getting +9v and -9v where you should, and the LFO is working, that means that all is well with the MAX1044 and the TL074. So it's just the audio path you need to check, including the FET. Go through with an audio probe and find the spot where the audio dies.

[Skruffyhound]

It's not unusual after some serious fiddling with an effect that after all that turning back and forth, for example checking positions in an enclosure, that one of your wire's out from the board has broken or lost contact. It can still be attached, but a cold solder joint has been exacerbated to the point where the bit of solder that was carrying signal is broken. Check for continuity.
This is a classic problem "it worked before I boxed it up", so you will find the answer. What did you do to it when you put it in the box? Did you remove anything to fix it in the enclosure and then reconnect, did that go back together right? Trace your steps back.
Good luck

[1878]

You could be on to something there. I want the controls in a slightly different order than what the board would give, so I've attached wires. Some of the wires were too short so I removed them and added new ones. I was a bit edgy and tired after a weeks work and I rushed it all. I'll set an hour or two aside one night and do a proper job.

I'll get the audio probe onto it tomorrow. It's probably something really simple... Hopefully.

[shaolin_skate]

Hi, first post on this board. Been looking for info on the Gristleizer. I am using a protoboard layout and had just started soldering the IC sockets when I came across some questionable information. I am reading the TG biography "20 jazz funk greats" by Drew Daniel, and in the forward he mentions the Gristelizer. This quote is from the last paragraph of the preface: "...members of TG have copped to deliberately misleading the public with partial self-revelations in the past (such as Chris Carter's admission that the published schematics for his custom-built "Gristle-izer" contained inaccurate voltages inserted into the plans with the express purpose of throwing people off the scent and sabotaging any attempts to copy his design)."
Anybody know about this? I am using the Gauss-Markov schematics by the way. Has anyone actually got this thing working and confirmed it's proper operation? Thanks.

[jacobyjd]

I have gotten the gaussmarkov project up and working. Check out my build report by searching this forum. It's a fun circuit.

Taylor's PCB is essentially the same thing, just a little more modernized and mod-friendly.

[Taylor]

Lots of people from various forums have built this with my PCB and found it to work (I of course have too). I believe most people who build this bypass any info from TG completely and go straight to the GEP article that Chris Carter built his from. Roy Gwinn, who is a member here, is the designer, not Chris Carter, and though I'm no TG fan and don't know much of their history, I would assume he built it straight from the article.

I mean no offense to those guys, but I don't imagine they knew or cared much about electrical engineering, just like most musicians, so I wouldn't put too much stock in any grandiose claims of their "inventions". I don't think they did anything to this circuit but name it and make it popular (by the standards of industrial noise effects, anyway).

[mrfang]

Thanks Taylor for a great PCB design!

I built my Gristleizer with minimal stress this evening, and it works, but I'm having that ticking problem that other people have mentioned.  It doesn't seem to be lessened by adding the optional 10uF cap, or other values of caps in that same spot.

Does anyone have a confirmed solution to the ticking problem?

[Taylor]

If you read through the thread there have been a number of suggestions like putting a cap across the IC power pins, etc.

[1878]

I finally got this boxed up !! No gut shots as yet 'cos it's a shit tip, and I wont have time to fix it before I move house.

[Taylor]

Cool! What's the c/p switch?

[1878]

Nothing too interesting unfortunately. It's the 'Cap or Pads' switch for the optional 10uf cap. I've tried a few different values in there with differing results. I think it's a 100uf at the moment.

[Skruffyhound]

Really like your graphic/colours, simple eye-catching and colour coordinated, top marks 

[1878]

Really like your graphic/colours, simple eye-catching and colour coordinated, top marks 

Cheers 

[ren]

Hi.
I've got the diy kit from endangered audio and I have the same ticking problem (even in Bypass).
In my stompbox the ticking depends on the position of the bypass switch and the output jack relative to a spot of the PCB.
Probably some kind of cross talking. But I don't know, if shielding the wires solves the problem completely. Just an idea.
Removing the LED had no effect on the sound.

[Taylor]

Hi there, I can't tell whether you're offering help or asking for help. If it's the former, thanks for contributing! If the latter, I'd suggest talking to the Endangered Audio guys. They had some unkind words for me at one point, because I created this PCB - so I'll abstain from discussing how to work with their board as this seems to offend them.