Soulsonic Hunny Bunny - no sound. Stumped.

[tracer03]

Soulsonic Hunny Bunny Layout

Built this one twice, with identical results: no output. Used an audio probe and the signal seems to die at Pin one, as it gets almost synthy, then nothing. Tried multiple TL072s with identical results on both builds - even pulling a known working TL072 from another build.

Reflowed all solder joints, knifed strips, checked continuity with my DMM (no issues).  I am stumped. Any ideas? Thanks in advance.

IC Voltages (almost identical across two ICs):
1 - 4.04
2 - .835
3 - .787
4 - 0
5 - 4.84
6 - 8.75
7 - .765
8 - .871

BS170 Voltages:
D - 8.78
G - .755
S - 0

[PMowdes]

Why are you using a tl072???  It's a dual opamp

You need an LM301 which is a single opamp, they are not interchangeable

[PMowdes]

TL072



LM301

[tracer03]

John K posted that he used one in the comments with better results: I didn't think that any mods needed to be done to the circuit (at least there didn't seem to be). Could it be a typo, and he meant TL071? I wasn't sure about the op-amp substitution.

John Kallas 29 July 2013 at 05:26
okay, just for kicks, it tried another brand of LM301N. the first one was a National semi and the second one an ST Microelectronics one. both of them sounded identica (like ass!). overly compressed, spongy and UGLY! then I tried a good 'ol 741, ad TL072 and an OP07 and all of them sound great in it (i.e. smooth & articulate!)i'm going to use a reverse log pot for the honey control and this one is now easily worth boxing it up. funny how just a single chip in this one makes a HUGE difference between liking it a lot and throwing it in the bin.

[tracer03]

Okay, tried an LM301 and a LM741. Same thing, no signal. Decided to rebuild and it works fine. A little noisy, but we'll see what happens when I box it and swap in some different ICs. (the RIGHT Kind this time). Mus have been a bad component somewhere.

[PMowdes]

Glad you got something working.

Looking at the voltages you posted above there is definitely something wrong,  You should have had something close to 9V at pin 7 on the IC