[sdiy] Tempco group buy news

[Ray Wilson]

>From the designs I have seen (and use) the inverting CV buffer usually has 
an input impedance (actually resistance) of 100K. 100Ks  are used as the CV 
summing resistors and a 2K tempco as the feedback resistor. This results in 
a gain of 1/50th. A trimmer hangs off the output so you can trim to 18mV per 
volt applied to the base of the logging trannie. If you use 1K tempco in the 
feedback just use 50K resistors for the CV input summer and you will be good 
to go. This will reduce the input impedance/resistance to 50K but that 
should not be too significant if your CV source is way low impedance <= 100 
ohms. I can only speak to the design I use other designs use the tempco 
differently and thus the value may not be so easy to change from whatever is 
specified.

http://www.musicfromouterspace.com/analogsynth/VCO200503REV01/VCO200503REV01.html

And as always a plug...
I have 2K PT146s in small quantities for $6.50 a piece. Yes, I'm making a 
profit on each sale... gotta support this habit somehow.

http://www.musicfromouterspace.com/catalog.php?page=CATALOG

Ray


----- Original Message ----- 
From: "Ian Fritz" <ijfritz at earthlink.net>
To: "Metrophage" <c0r3dump23 at yahoo.com>; <synth-diy at dropmix.xs4all.nl>
Sent: Sunday, May 29, 2005 10:33 AM
Subject: Re: [sdiy] Tempco group buy news


> At 09:22 AM 5/29/05, Metrophage wrote:
>>Much more interest than I had expected! I will be in contact with KRL
>>again tomorrow with more specifics.
>>
>>Another surprise, one audacious person is having me get a big heap of
>>2k tempcos also. I hadn't spoken with KRL about those last week, as I
>>didn't know if there was much demand. Since I will ask them tomorrow,
>>anybody else interested in some 2k tempcos?
>>
>>CJ
>
> 2k is more of the standard here.  1k is used mainly because 2k is harder 
> to obtain.