[sdiy] Looking for layout opinions

[rsdio at audiobanshee.com]

How about:

3) Move 2 of the VCAs for the main VCO circuit to the wave shaper board. That makes a little more room on the crammed VCO board, but splits a couple of VCAs across two boards. Then you have just 3 quad VCA chips and no waste.

Brian


On Jun 24, 2018, at 10:55 PM, David G Dixon <dixon at mail.ubc.ca> wrote:
> I'm in the process of laying out one of my circuits (actually the Rubicon 2
> TZFM VCO) for through-hole PCBs and 5U construction.  I am nearly done with
> the layout, but I've come up against a conundrum, and I wanted to get some
> outside opinions.
> 
> The circuit layout will have to be on two separate PCBs, which I've managed
> to limit to 4" x 6" each.  I've got the main tricore VCO circuit and TZFM
> circuitry all done on one PCB, which is completely crammed.  All of the
> waveshapers, suboctaves, Warp, and Squish will go on the second board, which
> is not quite as crammed.
> 
> So, here's my issue:
> 
> The entire circuit requires 12 VCAs (three 2164 chips).  The main VCO
> circuit requires 10 VCAs and the Warp circuit requires 2 VCAs.  However, the
> Warp circuit is on a different PCB.  I have actually put all three 2164
> chips on the main VCO board.  However, there is plenty of room on the shaper
> board for another 2164 chip.
> 
> So, here's what I want your opinion about (sort of a "What would you do?"
> kind of thing):
> 
> Should I:
> 
> 1) Lay out the 2 Warp VCAs on the main VCO board and connect them to the
> shaper board with wires, thus splitting the Warp circuitry between two
> boards?
> 
> Or, should I:
> 
> 2) Use a fourth 2164 chip on the shaper board, only 2 VCAs of which will be
> used, thus keeping all the relevant circuitry on the same board (and wasting
> the equivalent of one entire 2164)?
> 
> My inclination is to lay out for both possibilities and let the end builder
> decide how to handle it, but that seems kinda stupid.  I'm curious what
> y'all think.  The cost of doing the second option is about $5 (chip plus
> socket), so it's not exactly a life-or-death decision.
> 
> Cheers,
> Dave Dixon