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.
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.
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.