AW: [DIY-PCB] Do you want to participate in discussions?

[Haible Juergen]

	>1)  Sliders - should we go with 60mm (3.94 inch) sliders?
	>    I see CTS, Xicon, Bournes and Panasonic in my catalogs.
	>    Since they each have a different footprint, our PCB layout
	>    person will need to either (a) make a PCB for one type
	>    of slider, or (b) route the traces for the two most common
	>    footprints.  Two specific brands and model numbers would
	>    be "recommended" for that part.

My catalogue has Alps and RadiOhm (but these RadiOhm are crap) ...
Maybe the person who sells the Pcb could sell it with a set of silders ? 

> http://www.synthfool.com/diy/jh_ipscan.html
> 
	>Juergen's recommended panel layout contains 8 stages, with
	>8 input amount sliders, 
	>8 signal indicator leds,
	>8 inputs,
	>two directional CVs with attenuators,
	>a manual control knob,
	>a DC offset switch,
	>and one or two outputs

If you have the panel space, add a 3rd CV input. I always run out of
CV inputs. Even a built-in VCA for VC attenuation of one CV
input would be good - I find myself patching an external VCA here
all the time. (Important for dynamic waveshaping. Run a triangle
wave thru a VCA, and then to the Scanner.)


	>Harry Bissel has drawn up a full 8 stage schematic.
> http://www.ionet.net/~roytate/images/hb_interp_scanner_schem.gif
	>
	>Harry's schematic uses the SSM2164, but could use another
	>high quality part ...
> http://products.analog.com/products/info.asp?product=SSM2164
	>
	>The original schematic used the SSM2024, but Harry's schematic
	>uses the SSM2164.  Note the change in gain control from current
	>to voltage.

Has anybody breadboarded this ??
I highly doubt that it works. Doesn't the 2164 has exponential CV inputs ??
I refer to Fig. 23 in the data sheet. There is no hint that one could abuse
the expo voltage inputs as linear current inputs (as you can on a 3080,
for instance). And if I got that last sentence in the data sheet right, they
blatantly tell us that the CV characteristic was changed from linear
to exponential, "but the expo control input is better anyway".
I thought we had already discussed this on the list in all depth.
(This is all just theory from my side. I've never used a 2164 myself, and I
will stand corrected if it actually works - but I doubt it.)

JH.