Take an oscilloscope probe or digital multimeter, and touch the output
pin of the CA3140, to see whether you see the roughly 5 volt sawtooth
or 5V AC signal (on the DMM).
If you don't, your problem COULD possibly be the 2N jfet transistor
not seated in the correct polarity. Though it may LOOK correct from
the top down, it could possibly be 180 degrees out. Find a pinout for
that tranny, showing the Gate, Source and Drain leg #'s and whether
they're shown in the diagram from the TOP DOWN or from the BOTTOM UP.
I have made this mistake a couple of times over the years. :)
There is also a modification that Ken lists on the related webpage for
the VCO output TO the Clock that is driving the VCF portion. I had to
do this, on my 1st of 2 BiNTic modules. (I haven't completed the 2nd
one yet.)
Also - building the BiNTic STOCK, you wont be able to have a separate
VCO output, from the VCF. The VCO is hardwired to the VCF's clock
control. (Which controls the timing of the 4051 muxes, for switching
the capacitors.) I'm doing a modification to the board to buffer the
VCO output as well as bring it (Sawtooth) and 2 separate Pulse Wave
with Pulse Wave Modulation outputs, to the front panel, along with a
Clock Input jack.
You'd said that the Bandwidth and Damper controls are working. Your
VCO probably IS working, as it's switching the clock. With the
Frequency controls not working though, check all of your solder points
around the dual opamp summer for the CV Inputs (which includes the
Frequency controls.) Check with a multimeter in continuity, whether
the traces conduct, all the way through the IC sockets, to the actual
IC legs. Quite often, I myself have found legs unsoldered. :)
Hope this helps for both of you. :)
(Back to lurking. Trying to figure out how I screwed up my Internet
connection on my old computer, when I was trying to network my new
computer with it. :( Don't know when I'll be back on for sure.
(Wishing I had the Networking For Dummies book. :O :) )
--
Take care,
Warmth and Peace,
Ryk
http://www.sdiy.org/damian/index.html
pin of the CA3140, to see whether you see the roughly 5 volt sawtooth
or 5V AC signal (on the DMM).
If you don't, your problem COULD possibly be the 2N jfet transistor
not seated in the correct polarity. Though it may LOOK correct from
the top down, it could possibly be 180 degrees out. Find a pinout for
that tranny, showing the Gate, Source and Drain leg #'s and whether
they're shown in the diagram from the TOP DOWN or from the BOTTOM UP.
I have made this mistake a couple of times over the years. :)
There is also a modification that Ken lists on the related webpage for
the VCO output TO the Clock that is driving the VCF portion. I had to
do this, on my 1st of 2 BiNTic modules. (I haven't completed the 2nd
one yet.)
Also - building the BiNTic STOCK, you wont be able to have a separate
VCO output, from the VCF. The VCO is hardwired to the VCF's clock
control. (Which controls the timing of the 4051 muxes, for switching
the capacitors.) I'm doing a modification to the board to buffer the
VCO output as well as bring it (Sawtooth) and 2 separate Pulse Wave
with Pulse Wave Modulation outputs, to the front panel, along with a
Clock Input jack.
You'd said that the Bandwidth and Damper controls are working. Your
VCO probably IS working, as it's switching the clock. With the
Frequency controls not working though, check all of your solder points
around the dual opamp summer for the CV Inputs (which includes the
Frequency controls.) Check with a multimeter in continuity, whether
the traces conduct, all the way through the IC sockets, to the actual
IC legs. Quite often, I myself have found legs unsoldered. :)
Hope this helps for both of you. :)
(Back to lurking. Trying to figure out how I screwed up my Internet
connection on my old computer, when I was trying to network my new
computer with it. :( Don't know when I'll be back on for sure.
(Wishing I had the Networking For Dummies book. :O :) )
--
Take care,
Warmth and Peace,
Ryk
http://www.sdiy.org/damian/index.html