Another Filter Sample + Hold problems thread...

[moosapotamus]

What are you using for the "noise" transistor? Back when I built the GGG version with Tonda's mods, I think I tried a bunch and ended up going with 2N2222. I also recall wishing that I had installed a multi-turn 10K trimmer for the S&H, as it was really touchy. I don't think it was controlling the S&H level, tho. It seemed like it was controlling the amount of randomness. Took a while to find a setting that sounded suitably random.

~ Charlie

[chicago_mike]

2N3904 right now. But I have a lot more npns I can try 2N2222, 2N4401, and more 3904's.

Looks like everbody likes the 2N2222. Ill try that asap.

[chicago_mike]

Okay, I replaced the 3904 with a 2222...

SHe's almost working but I get a real low output. My output cap is not a .15 but a .22 since thats the closest I can find. I do have .1 Im not too sure if I want to use a .1 and a .047 just yet to get the right value.

The ticking is not as loud but it is still there and I still dont quite get the sample and hold function.

Im looking at the differences between the GGG and the TOnepad. THe NPN in the GGG is grounded. THe Tonepad version it is not.

[chicago_mike]

Sounds as ifs theres like a gate on the effect..

[moosapotamus]

Im looking at the differences between the GGG and the TOnepad. THe NPN in the GGG is grounded. THe Tonepad version it is not.

Q4 on GGG and Q1 on tonepad? They look the same to me.

I recall spending quite a bit of time tweaking those trim pots. Hopefully you just need to find the sweet spots, maybe? Good luck!

[chicago_mike]

Wierd, cause on my tonepad, the lug is free standing. Ah, thats kool I figure though.

Yeah Im tweaking around with her and a modde bassballs.

The output i the FSH just seems awfully low atm.

[chicago_mike]

I had a 2k2 in stead of a 22k for the CW to pin 1 of the 13700.

Now im only putting a 1khz sine thru it and it seems to be working but..I still get a lower output volume than bypassed.

Should I change the output cap to a smaller or larger value?

My input cap right now is a .22

[moosapotamus]

You are already using a bigger input cap than the scheme. I don't know how much that would attenuate the output, but if you want to test it, maybe try a smaller value?

[chicago_mike]

I will.

Also, I did find I had used some 2k2's where I needed 22k..

My main issue now, other than the low output.. Is the effect seems to die off. Fade off as if the batteries were going out. Im still going thru all my origional soldering and wiring and replacing a couple outboard parts here and there.

User error.