Super Simple Square Wave Made Simpler Help

[Austin73]

Just built the SSSWMS from Simon Pribecs vero layout (cheers Simon)

But having a few issues ie NO SOUND! arrggh if I hit my guitar strings really hard a get a very short fart and thats about it . Has anyone else built this via the layout? All components are stock except the 2n5088 is a 2n5089 and vr1 is a 10k pot at present.

Please help as I'm on nights and I'm too tired to think

Cheers

Aus

[choklitlove]

where's that layout again?

[Seljer]

in the layout gallery http://aronnelson.com/gallery/album95/squarewave

I have to admit, that I haven't actually built the thing only the layout, but it looked okay when I went over it (and I'm doing that again right now)

edit: and I can't find anything wrong with the layout
could you take the voltages on the opamp and the transistor? and possible use an audio probe, to see if the signal is getting past the transistor (on trace H)

watch the orientation of the opamp as pin 1 is at the bottom, not the top

[Nalo1022]

I built from this layout a couple days ago and I'm Having the same problem. DId you use electrolytic caps for C1, C4, and C6? I did as it appeared to have them in the layout, but because they didnt designate what polarity placement i made my best guess.

[choklitlove]

the polarity is marked.  the cap is a little darker on the negative side (look closer).  c6's negative is down, and c1 and c4's negative is upward.

[Nalo1022]

thanks alot! I had one cap backwards and i also had forgotten the jumper on Q1. I just got it working finally! Just got get it biased now. The sweet spot on the bias pot is really small.

[Nalo1022]

Austin, VR1 being 10k may be your problem. When I bias mine I get pretty much no sound (like what you where describing) until I get at about 3/4 of the trim pot, so you may simply be out of range.