Well, I fixed it. The problem was this: There are a pair of
resistors that come out of the 072, a 100K one and a 330R one, on the
opamp side of the 330 R one I'd managed to lift a pad, but you
couldn't tell by looking at it, I only found it when I was resoldering
the joints. I joined the 330R resistor to pin 7 of the 072 with a
short piece of wire, and hey presto, problem gone. I can't remember
the last time I lifted a solder pad!
the CPO out doesn't work, I found, but I'm sure it'll be something
similar.
I recorded a 5min noodle using it on 5 different tracks, which can be
found on this electro-music.com forum thread:
http://electro-music.com/forum/viewtopic.php?p=193269#193269
too much reverb, as usual!
resistors that come out of the 072, a 100K one and a 330R one, on the
opamp side of the 330 R one I'd managed to lift a pad, but you
couldn't tell by looking at it, I only found it when I was resoldering
the joints. I joined the 330R resistor to pin 7 of the 072 with a
short piece of wire, and hey presto, problem gone. I can't remember
the last time I lifted a solder pad!
the CPO out doesn't work, I found, but I'm sure it'll be something
similar.
I recorded a 5min noodle using it on 5 different tracks, which can be
found on this electro-music.com forum thread:
http://electro-music.com/forum/viewtopic.php?p=193269#193269
too much reverb, as usual!
--- In cgs_synth@yahoogroups.com, sasami@... wrote:
>
> It does sound like you have an issue around one op-amp.
> Try soldering a 47pf capacitor between pins 1 and 2, and another between
> pins 6 and 7 of the op-amp that is giving trouble. You may have a stray
> capacitance issue with all those long wires. If that solves it, do
the same
> to the other op-amps too as a preventative measure.
> Also, look for bad solder joints around the IC, or a wrong resistor
value.
>