Re: [AH] ASR Warmth. etc...

From Cynthia Webster
Sent Thu, Jan 27th 2005, 20:33

on 1/27/05 11:12 AM, James R. Coplin at moog@qwest.net wrote:

>> Now wait a minute...  I'm in 100% agreement with the idea that analog
>> VCO and VCF circuits are "warm" sounding (compared to virtual), but how
>> can a voltage coming out of a jack be warmer than another voltage coming
>> out of a jack?
> 
> [James R. Coplin]
> I'm being silly...
> 
>> Not trying to be silly or anything, I'm curious :)   Does the Serge ASR
>> voltage drop slightly over time?  Does it quiver up and down a bit?
> 
> [James R. Coplin]
> My ASRs are not completely stable when using them to hold pitch.  Your PSIM
> probably is more accurate.  Over time, there is some slight droop.
> 
> James (4 Droopy ASRs) Coplin


There is that trade-off between sample holding time, and high speed
operation up into the audio region.  Most ASR applications I feel are
not really used this fast, but more for melodic speeds such as what a
human player might realize if playing a keyboard.

I had a chance to see an ASR board in a 1970's paperface Serge,
and noticed very large ~polystyrene~ caps for this purpose.
(they look a bit like silver Tootsie Rolls).

Instead I find ~Polypropylene~ capacitors to be a bit more stable.
You might try replacing your ASR caps with this part number for
a noticeable improvement in the ol' droop factor.

Mouser.com part number

1429-1474      .47K,100MPP
Xicon Radial Metallized Polypropylene Film Capacitors


Best Wishes!


Cynthia

http://www.cyndustries.com/