> Ken,
> I've gone over the whole board all the whole board and it look
> alright.
as for finding the problem. it might help to check some voltages around
the circuit without any input coming in. try hooking up a voltmeter to
points shown on the schematic at :
http://www.aleph.co.jp/%7Etakeda/radio/steinerVcfE.html
thats motohiko takeda's modified version. it uses some different
transistors and resistors but I suspect that your measurments should be
close enough to get an idea whats going on. this might not be easy to
see since his transistors have a much higher hfe. the measurements on
the right hand side of the page show the DC biasing of the amplifier.
check those atleast. check the wiring like below first though.
> 3. Fair enough...I'm sure this will work out once it becomes clear
> how to correctly wire things up.
I've just built one reccently. I'll explain how I have it wired up.
It's pretty much the same on most modules. So hopefully next time it
won't be so hard.
from the schematic. the frequency pot is connected to +15v, ground, and
to one of the CV inputs. looking at the pot with the shaft pointed
towards you and the pins pointed down. the left hand pin goes to ground,
the middle pin goes to one of the CV inputs, and the right hand pin goes
to +15V. for the ground and the +15v, you can use the solder pads right
next to the power connector. the '+' is going to be +15v, the ground is
'0'. if you look at the underside of the PCB you'll see that there are
traces that also connect to the +VE and GND pads so those would work
too, but I used GND for something else. I'm not sure what +6 is for but
it's not needed.
for the res pot, connect the one pin to one of the res pads, and the
middle pin to the other res pad. It shouldn't matter which you choose.
for the jacks. connect the ground tags for all the jacks together, then
connect a wire from that point to GND on the PCB. You could also use the
'0' pad or some other place that is ground. I forgot the wire that
connected the jacks to the ground on the PCB on another filter once and
got something that sounded something like what you describe comes from
the filter in highpass mode.
if you use a level pot, hook it up just like the res pot.
> 4. This is the confusing part. How was I supposed to know the
> frequency pot is wired with its CW end to+15, its CCW end to
> ground/0V and its wiper to one of the CV inputs? Schematics?
> And where is +15 on the board? Is it just one of the +
> openings?
you would know this by looking at the schematic and also maybe the
datasheet for that pot. I knew from experience. understanding that the
frequency pot is working as a voltage divider would help also. think of
it like the pot is mixing 0v and +15 depending on the position. looking
at the pot like i described before. the pot turned all the way left
would give 0v output (the middle pin), all the way right gives 15v
output, and in the middle it would give something in between.
hope that helps,
Ryan