Anybody build their Gristleizer yet, comments on it?

[jackwithoneye]

OK, so your input stage is working right up before it hits the FET. Early on you said you had audio coming out, but it wasn't affected by the LFO. Now, your audio is not coming out of the output at all.

Have you tried messing with the bias pot after you got your LFO working? If you're not able to get any audio out regardless of how bias is set, I would think something may be wrong with your FET. If you can get your hands on another 2n3819, I would swap it out.

i ordered some 2n3819, i'll get back to you when i'll be able to swap and test!
thanks

[jackwithoneye]

Hey Taylor!
I've finally recieved my 2n3819 fets overseas, it took some time.... but it worthed it! my gristleizer is finally working just fine! A bad(or toasted) FET was the issue.
All waveforms and parameters are working as they should now, and i love it!
Thank you Taylor and everyone for the help and the tracking issues walkthrough. It helped me to understand circuit and i learned a lot.

Time for modding!! (but i'll probably wait a bit before frying anything else)

[Wingnut]

Hi first post here. I've read the entire 26 pages here before asking. (Took a while). I'm using this PCB and the components supplied in the kit from musicling. I have populated the board with caps and resistors, I have used sockets for the transistors. I assume that the tent shape on the PCB corresponds to the semi circle shape of the transistors. Some have commented about some transistors having different pin outs, I checked the data sheet for the2N3819, it looks different, to the DGS markings. Can someone clarify? Thank you

[bluebunny]

Welcome.

You're right about the screen print: it's intended to mimic the shape of the device.  As for the pinout, you really need to check the datasheet for the specific brand of JFET that you've bought.  Just doing a quick search, I've come up with results for DGS and SGD.    Happily, JFETs are often symmetrical, so it may not make a difference in this case.  Since you've fitted sockets, you can test out my theory!   

[jackwithoneye]

hi, i used the musikding kit too, and i can confirm that the print matchs the transistor orientation

[Wingnut]

Welcome.

You're right about the screen print: it's intended to mimic the shape of the device.  As for the pinout, you really need to check the datasheet for the specific brand of JFET that you've bought.  Just doing a quick search, I've come up with results for DGS and SGD.    Happily, JFETs are often symmetrical, so it may not make a difference in this case.  Since you've fitted sockets, you can test out my theory!   

.                                               
Hi thanks for that, I checked the fet and transistor brand and data sheets. The board is finished, with pots sockets switch's etc wired on. The led and speed pot work, as does the level pot. Nothing else works, apart from the VCA/VCF switch, although that just switches between mildly overdriven clipping and heavily breaking up Fuzz, but not in a good way. At least there's no ticking, lol. I've tried all settings as well as the trim pot setting instructions.

[Taylor]

So, it sounds like your LFO section is working and the audio section is letting sound through. That seems similar to what jackwithoneye was experiencing above - the two main sections work but not the part that connects them, the FET. Try picking up another 2n3819 from elsewhere to see if that solves it as it did for the above poster.

[Wingnut]

Hi Jack, thanks for the reply. So you built from the same kit. Shame they couldn't supply the correct rotary switch. Where did you buy your replacement get from? I've built a few things lately, preamps mainly and had issues with the fets.

hi, i used the musikding kit too, and i can confirm that the print matchs the transistor orientation

Did you have any ticking on your finished device?

[jackwithoneye]

Thank you for your answer Taylor
Ok i'll remove my 2 mod toggle switches. The second one is the optionnal 10uF cap, anti-ticks, which i putted on a switch. ( i didn't know if i would keep it or not)

I'd carefully checked continuity on the 2P6T before everything, and i can confirm how it's routed :






Blue wires are A1&B1 (pcb 2&7), green A2&B2 (pcb 3&8 ), Yellow A3&B3 (pcb 4&9), orange A4&B4 (pcb 5&10), red A0&B0 (pcb 1&6)
As you see,i putted jumpers over lug 4-5-6 on A, and B, to avoid dead positions on the rotary switches. So, square wave should be over position 4,5 and 6.

i assume that's i have been meticulous on this, and when i check continuity, over different lugs when it's wired, it makes sense regarding the rest of the circuit and the rotaru switch position.
I have a doubt on the FET, as i don't know how to test it, and how it should react, or give information on scope or not.(i'm still a noobie...)

i used the provided by musikding rotary switch with this wiring

[jackwithoneye]

sorry, can't figure out how to delete this wrong post....

[jackwithoneye]

Did you have any ticking on your finished device?

i dont have any abnormal ticking when the device off, when it's on some tickong can appear depending of the setting, but it can be part of the effect.
I added th optionnal 10uF cap on a switch, it reduce ticks, but change a bit the way that the effect respond to the LFO imo, that's an option. and added a LFO Off switch, because i read that some guys had some ticks going through the circuit even when it's off, but it's not my case.

Be conscious of the specific settings range of the device, Taylor, correct me if i'm wrong:
The main setting to play with, first,is the Bias knob, you'll find the sweet spots for a guitar level around 9 o'clock, it's very sensitive and changes everything. If you're above the sweet spot, the LFO influence disappear, so be aware.

[telebiker]

I'm curious, has anyone faced up to the issue when the effect has hi-freq hissing noise while on? It's loud enough to be clearly hearable, however, the wet signal is louder and also very clear. And hissing increases when something exists in the input jack.

Make sure your 1044 I'd the scpa variety. Needs the "s" or they will make high pitched whine in audio devices

Thanks for the tip! Want to confirm that with TC1044SCPA there's no hiss at all.

Shame they couldn't supply the correct rotary switch. Where did you buy your replacement get from?

Small bear has them (and they have part number if you'd like to find it somewhere else): http://smallbear-electronics.mybigcommerce.com/26mm-enclosed-3p2-4t/

BTW, I have a little bit of ticking in my build while the effect is on, but probably I have to tweak trimpots.

[telebiker]

BTW, finally the pedal is completed. I've also done the LFO input mod and the smooth toggle switch (and the LED switching mod). I shouldn't have used a drill template for another project

[eh la bas ma]

Hi, I did the Gristleizer in august. I do have some ticking.
The only solution so far, has been to tweak both Bias and Deppth pot to clear the signal.

I really had a hard time wiring the rotary switch because the switch on the instructions didn't look like the switch i received.
Finally i got somewhere, but i am not even sure it is right.

Nevertheless, I like to use it after everything, even after the reverb, with high distorsion, to give some fast-stuttering effect to some note time to time. And it is really a pleasure.

The first waveshape is really smoother than the three others. Here is some pictures in case it could be improved :

[telebiker]

Looks like musikding kits do not have the proper rotary switch

[Wingnut]

So, it sounds like your LFO section is working and the audio section is letting sound through. That seems similar to what jackwithoneye was experiencing above - the two main sections work but not the part that connects them, the FET. Try picking up another 2n3819 from elsewhere to see if that solves it as it did for the above poster.

Cheers Taylor all done now, it's not as distorted as before, although there's a lot to explore yet. I think the original get wasn't pushed into the socket properly. Am I right thinking, from left to right, clockwise, square, slope up, slope down then triangle? I'm setting the trims by ear.

[telebiker]

Am I right thinking, from left to right, clockwise, square, slope up, slope down then triangle?

In my case it was slope up → slope down → triangle → square.

[Wingnut]

/quote]
That's what I'm getting, I think, assuming the triangle is quieter, as I don't have a scope. I know the triangle is quieter on a hex drone box I made, as it uses caps to smooth the square wave.

[telebiker]

Actually I would recommend to set up trim pots without square wave smoothing, thus you would get more proper square wave.

[Wingnut]

Cheers, I haven't used smoothing caps on this. What I meant was I assumed the triangle was the quietest wave, because a square wave drone box I made, has a teaingle setting, which is quieter, due to the smoothing caps used to create that shape. Hopefully I can get that gnarly distortion back. Then I can box it up. Initially it worked like a distortion/fuzz with no modulation, I swapped out the jfet,as advised by Taylor (thank you) now I've lost that lovely TG growl. I'm hoping it's because I've socketed the transistors and they're not seated right, a problem with the sockets I used. Maybe fold up the excess on each leg, giving more surface area, holding them closer to the board, or just hardwire them.Ivevjusr rebuilt a Teisco, the same as Cosey used, I ran it through a Tube Screamer and DS1, (clones) then parallel through a matrix mixer into a Univox, £20 nano fuzz and an unshaven fuzz, feeding them all into a bucket brigade, then tremolo. Slug Bait and Hamburger Lady, it was like she was in the room, going to through some reverb at it today.