calling j luja, F.P. or rob strand...

[swt]

Hey guys. I've been working on my microsynth clon, and i'm at the process of debugging. Bill Bergman is helping me with this, but he can't remeber who of you helped him when he built it.
My problem is that i have low signal at the output. I think i have isolated the problem, it's in the last ota. But can't realize what can be. Any ideas about the schem being wrong, or how to solve it?. Thanks a lot for any help!!

[Fp-www.Tonepad.com]

I think it was me.

There was a small error with the schematic, I'll have to dig up a bunch of email to find it.

I'll post when I do. (It'll be a while though).

IIRC it was something like a connection to ground that had was drawn as -v, or something like that.

I wish I could help more right now.

Fp
www.tonepad.com

[Bill Bergman]

Did you put in the jumpers(yellow dashed lines on the layout) on IC 3 and 13?

[swt]

yes i have all those jumpers.
All the circuit is working, but with a really low signal. I have a true bypass installed. I tested the input by soldering it to the output, and it has a big boost in it. I have also a big boost after the 700 hz filter. But if i put the output of the input, in this case point 1 in the pcb, into the output mixer, ic 14, then the low signal appears. So i'm betting 90% to that output section. The attack delay seems to work fine, and i have everything checked, and it goes according to the schem, that's why i think there has to be something wrong in it. Hope i find it someday, because if i turn th amp up, it sounds amazing. Thanks you guys for all this support and help!

[Paul Perry (Frostwave)]

Which synth is this? Where circuit? thanks!

[swt]

Further advances. I was wrong. it's not the output section. The guitar signal is ok. Also the suboctave is working properly. I've tested the end of the full wave rectifier and i have loud signal, but then at the output of the octave pot, the signal comes down considerably, so there's a deal right there. The square wave seems to work, but it sustains the note for a while, and cuts it abruptly. The filter section is rather tricky. The 470 ohms resistor going to pin 3 was loading down the signal. If a take it out, i got some kind of misbiased distortion, so i've put a 470k, and it's working. Got to work more on that one. I'm not sure if the zener and 10uf cap (d18-c28) should be connected to v- or ground.
I'll keep you informed, and i'll try to get a real one to see what can be wrong.

Hey Paul!. Send me en email. i'll send you the pdfs.
sfeirwt@infovia.com.ar

[Bill Bergman]

The square wave control boost the over all volume of the synth section but if you want it clean you have to settle for a lower volume. Try adjusting the squelch control to sustain the note.

[swt]

Ok...i think i'm stucked.   . I have a friend who's got a real one. I'll ask for it and try to get what's wrong with the schem. I've double checked, and the circuit is as in the schem. Hope to get it :?

[swt]

i'll have the real thing on monday. i'll have for four days. Hope i can trace it or at least make the necessary corrections to that schem. I'll let you know. Meanwhile, anything you can remeber is welcome. Thanks!