Now this is wrong. Tested the second VCO (had the correct TL0__
device in place!) and get the same result as the first. VCO core is
fine - actually works very well! The sawtooth from the core
completely goes away at the pin 1 of the TL072 for the saw output.
I checked for a simple short to ground, but no such luck. Cap
polarity is correct and the TL072 has correct voltage at pins 4 and
8.
Another oddity - the sub input and output work as expected. But if
I plug my square wave audio into the square wave out jack, which is
connected to the sub input when no plug is in the sub in, frequency
is halved!
This is really odd. How can such a simple stage as the saw and
square output amplifier be causing me so much grief? Has anyone
else built the rev .3 pcb? When I get a chance, I'm going to follow
the traces. In the meantime, I'm going to try to calm down.
Any ideas?
Chub
device in place!) and get the same result as the first. VCO core is
fine - actually works very well! The sawtooth from the core
completely goes away at the pin 1 of the TL072 for the saw output.
I checked for a simple short to ground, but no such luck. Cap
polarity is correct and the TL072 has correct voltage at pins 4 and
8.
Another oddity - the sub input and output work as expected. But if
I plug my square wave audio into the square wave out jack, which is
connected to the sub input when no plug is in the sub in, frequency
is halved!
This is really odd. How can such a simple stage as the saw and
square output amplifier be causing me so much grief? Has anyone
else built the rev .3 pcb? When I get a chance, I'm going to follow
the traces. In the meantime, I'm going to try to calm down.
Any ideas?
Chub