mix resistor values...

[List, Christopher]

I didn't have the log response on mine! I used 100K pots and 1M resistors
for all rows.
I'm just saying you *might* want it that way on just one row, for the added
variety. If, for example, you were planning on using a row to control master
volume and you had a linear CV for your VCA. Or perhaps you have a VC-ADSR
with linear CV inputs.

For pitch CV's, you would do best to stick with linear response. So you
might do best to just forget I ever mentioned anything about the log curve
:) Or use an external exp. amp if you want that...

One other thing that I did with my sequencer that I forgot to mention was
that for each row I have a switch that changes the scale for the row from 0v
-> 5v to 
-5v -> +5v. I find this very helpful. I was able to do it with DPDT
switches, and without a lot of wires going from the switch to the op-amp on
the PCB, though I forget exactly what tricks I used to accomplish this. Note
that the input for each row is +15v when the row is "on" in all cases - the
switches are tied in to the summer on the output.

- CList

> -----Original Message-----
> From:	WeAreAs1 at aol.com [SMTP:WeAreAs1 at aol.com]
> Sent:	Wednesday, August 11, 1999 10:04 AM
> To:	Chris.List at sc.siemens.com; synth-diy at mailhost.bpa.nl
> Subject:	Re:  RE: mix resistor values...
> 
> 
> In a message dated 8/11/99 5:05:54 AM, you wrote:
> 
> <<You might want one row of pots with
> the pseudo-log curve you get from a low pot + high resistor combination...
> 
> For my seq. I used 100K pots with 1Meg resistors. I never had (or noticed)
> a
> problem with noise - but then I have no facility for muxing in external
> audio to one of the rows, I only using it for generating CV's. >>
> 
> Hello Chris -
> 
> Why did you want the pseudo-log curve on your CV pots?  I would think that
> 
> linear pot response would be best for tuning pitches (when driving
> 1v/octave 
> inputs... you're not using linear VCO's, are you?).  With linear pot 
> response, you get an equal amount of pitch change for an equal amount of
> pot 
> travel.  For example, if the total CV range is 2 octaves, the pot will
> have 
> 24 equally-spaced sections of travel, giving a total of 24 half steps.
> This 
> should make it easier to find the desired pitches, especially if one
> doesn't 
> have a CV quantizer.
> 
> Michael Bacich