Cgs synth

The 2n4391, 2N4091 etc. in metal cans MUST be put in backwards with respect
to the "D" shape on the overlay. Perhaps that is the problem?

KEn

>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
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>

_______________________________________________________________________
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.cgs.synth.net/>
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