Anybody build their Gristleizer yet, comments on it?

[mth5044]

Based on that schematic, it looks like you are shorting your + and - together on the switch, left row, top and middle lugs, when the effect is on!

It also looks like you need to switch the LED switching some how?

Check out this little guide:

http://www.madbeanpedals.com/tutorials/downloads/MBP_FootswitchWiring.pdf

[StonedDiplodocus]

Hi mth5044 and thank for your answer.

Ok, so I tried "the completed 3pdt wiring" (fig.10) of the fifth page of this document (very interesting) And it's doesn't work again... The Red led on the board if always lighting, the second never, and the sound was bypassed (clean sound, no buzz or hum).

Check this  :

[mth5044]

Just read the build doc - I see the LED is a rate indicator and says this shouldn't go off when the pedal is off.

Does the red LED flash at all when you change the depth and speed controls? This is likely a separate problem from the indicator LED below. Do you have a Volt meter and can you take voltages of the project?

The other LED not lighting indicates the wiring is wrong or perhaps the switch was over heated and isn't completing the circuit, or the LED is backwards. Can you supply photos?

[StonedDiplodocus]

No effect or varations when I turn all pots. Well, I check the 3PDT switch and effectivly the switch was over heated...

Thank, I will change it tomorrow because it's too late (4 am in france).

Thank a lot, I'll tell you if it's better. Have nice day. 

[Marcos - Munky]

Just by curiosity, did you tested the circuit? If no, just hard wire the circuit to input and output jacks and test it. It's better to be sure the circuit is working before you add the 3pdt.

[StonedDiplodocus]

Hi, I tested and No signal... I check all the resistance and I find strange values check this




Different picture of my circuit ( the In and the Out was reversed on the 3PDT switch, it's normal) :

[Mr. Z]

Hi all, first post here.  I'm having difficulty with my Gristleizer build.  I purchased the Fuzzdog kit and am getting a short somewhere in the circuit.  I would like to use the R.G. de-bugging method but the battery is getting hot to the touch and draining the battery after a couple of minutes so it's impossible for me to note the voltages to the I.C.'s.
I should mention that I do not currently have a bypass switch, LEDs, or in/out jacks wired in yet.  Also, I'm not getting any continuity between pin #5 of IC 1 (7660s opamp) and -9v. 

Any suggestions as to where I should start looking would be greatly appreciated.  Thanks.

[BetterOffShred]

This thread is for the MusicPCB board.. if that's what fuzzdog is selling then I stand corrected.  You need to follow the schematic and see where you have the potential for a short.   Does it have a polarity protection diode you accidentally put in backwards or something simple ? 

[Mr. Z]

My mistake, I thought this was for general Gristleizer build discussions...there are 2 polarized diodes.  I double checked that they're the right way in so it's not that.   I'll check the schematic again.  It has to be something simple I overlooked. 

[bluebunny]

If the battery gets hot and dies quickly, then you have a short.  Lose the battery and go hunting for continuity (or very low resistance) between the power rails.

[duck_arse]

My mistake, I thought this was for general Gristleizer build discussions...there are 2 polarized diodes.  I double checked that they're the right way in so it's not that.   I'll check the schematic again.  It has to be something simple I overlooked.

Mr. Z - welcome to the forum, and does your board match the one shown in this thread?

https://www.diystompboxes.com/smfforum/index.php?topic=120286.0

[Mr. Z]

My mistake, I thought this was for general Gristleizer build discussions...there are 2 polarized diodes.  I double checked that they're the right way in so it's not that.   I'll check the schematic again.  It has to be something simple I overlooked.

Mr. Z - welcome to the forum, and does your board match the one shown in this thread?

https://www.diystompboxes.com/smfforum/index.php?topic=120286.0

Hi, thanks for the welcome.    No, my board is different.  The rotary switch is mounted directly to it.  I am definitely getting continuity between -9v and ground but can't pinpoint where the short is yet...

[Ben_buttons]

Hello hello

Is any one out there that can help me with an issue I have with this Gristleizer PCB. I'm getting a very severe high pitch tone coming from the output. I bough a couple of the PCB's and they're both outputting this same tone. As far as I can tell I've installed the corrected listed parts but my experience of electronics is purely amateur so I might be wrong.

I'm going to do some extensive probing but just wondered if anyone had any thoughts on what could cause this?

[pinkjimiphoton]

yeah, you got the knobs set too high, and its up near dog whistle range. try setting the knobs WAY lower... maybe 9-10:00. if the sensitivity knob is too high, it will be working above the audio range of the guitar. this thing does some seriously whack shit.

when i first built it,  i thought it wasn't working cuz i had the knobs all the way up, and it don't do nothing but squeal like that. its totally capable of self modulation, and ring modulation.

so cut the knobs way back, and advance them just a little tiny bit at a time. then report back.

[Taylor]

Also, which charge pump did you use? There are several with the same pin layout, but some have the "boost" function which raises the oscillator frequency above the audio range, and some don't, which could be the source of the whine.

[BetterOffShred]

Yes the 7660s from Tayda squeal like a B..   also the bias knob needs to be adjusted for each wave shape and depth setting as you move through them. 

More expensive .. but Mouser 7660s are quiet

[Ben_buttons]

I used a Max1044 charge pump. The whining sound seems to be present whatever I do. Very frustrating!

[Taylor]

Check with your continuity meter that pins 1 and 8 on the MAX are connected.

Also, what sort of power supply are you using? I have had some old switching supplies (VS One-Spots in my case) that, after some years will produce a very noticeable whine. Could be more noticeable in the Gristleizer due to high gain and general noisiness of the circuit.

[Ben_buttons]

Hey, thanks for all the suggestions. I'm still struggling to figure out why I'm getting the noise. I'm using a 9v battery to power the pedal. It's not boxed yet and I get the noise regardless of any pot adjusting although it does adjust the volume of it. I've read a lot about switching noise from certain charge pumps and it makes sense this would be the cause. I've probed the circuit and found the noise is traveling through 0v and  + and - voltages.
I thought maybe it was a grounding issue so I've tried a few different configurations of connecting the grounds together but it makes no difference.
I've swapped out the Max1044 on two different circuits with the same results. I'm thinking the chips I have might be inherently faulty so I've ordered more from elsewhere. Are there any obvious and very stupid things I may have done? I've listened to other examples of the gristleizer sound and I don't hear this same sound in any of them.

So stumped!

Maybe I've done something incredibly stupid. I'm preparing to kick myself.

Here's an image of the circuit

[lulu_joe13]

Sorry I can't be much help. I struggled as well but it was long ago and I can't remember the details anymore. I can only say that your struggle is worth it. I can make sound effects that sound like nobody else when I use mine. JoeF