[ProAudio] Western Electric 111C transformers

[Bob Katz]

Now we're cooking!

Dear Bill: Thanks.

Yes, I am looking for color. I understand the series resistor. I'll 
probably use a dialpot so I can log the setting for recall.

On the secondary side, are you suggesting a variable load R with the C 
across it?

If I am looking for color and want to do some measurements to see the 
effect of various source and load devices, clearly a square wave 
investigation will tell me something. Frequency response will tell me 
something. What about harmonic distortion... probably look at THD at low 
frequencies???


Best,



Bob





On 1/29/22 5:15 PM, Bill Whitlock via ProAudio wrote:
> If you're after coloration, the strongest influencer of distortion is 
> source impedance, so I'd put something like a 1 or 2 k-ohm pot 
> (connected as a rheostat or variable resistor) in series with the 
> primary high side terminal.  At high-resistance settings, you'll' get 
> some level loss - and possible high-frequency loss if there's much 
> capacitive load (or cable) on the secondary side.  Putting a variable 
> load resistance on the secondary, along with some intentional 
> capacitive load to bring resonance down toward 20 kHz) will allow 
> control of the resonance's Q.  I don't recall off-hand where the 
> natural self-resonance of the secondary is, but I'd start with 1 nF or 
> so and use a 50 k-ohm pot (with a series 1 or 2 k resistor to keep 
> resistance from going to zero) variable load resistor. Results  will, 
> of course, guide you from there!
>
> Bill Whitlock
> AES Life Fellow
> Whitlock Consulting
> Ventura, CA
>
>
> -----Original Message-----
> From: Bob Katz via ProAudio <proaudio at bach.pgm.com>
> To: proaudio at bach.pgm.com
> Sent: Sat, Jan 29, 2022 1:16 pm
> Subject: [ProAudio] Western Electric 111C transformers
>
> Hola, Guys. I’ve got a pair of these sitting around doing nothing. I’m sure their effect will be subtle but it might be nice to package them into a passive box for their color in a mastering session.
>
> To vary their color would you have any suggestions on switchable buildout or termination resistors or zoebel networks I might want to add to the box, in addition to hard wire bypass?
>
> Appreciate any suggestions. Thanks
>
>
> Bob
> -- 
> If you want good sound on your album, come to Bob Katz 407-831-0233 
> DIGITAL DOMAIN MASTERING STUDIO Author: *Mastering Audio* Digital 
> Domain Website <https://www.digido.com/> No trees were killed in the 
> sending of this message. However a large number of electrons were 
> terribly inconvenienced.
> _______________________________________________
> ProAudio mailing list
> ProAudio at bach.pgm.com
> http://bach.pgm.com/mailman/listinfo/proaudio
>
> _______________________________________________
> ProAudio mailing list
> ProAudio at bach.pgm.com
> http://bach.pgm.com/mailman/listinfo/proaudio
-- 

If you want good sound on your album, come to Bob Katz 407-831-0233 
DIGITAL DOMAIN MASTERING STUDIO Author: *Mastering Audio* Digital Domain 
Website <https://www.digido.com/> No trees were killed in the sending of 
this message. However a large number of electrons were terribly 
inconvenienced.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://bach.pgm.com/pipermail/proaudio/attachments/20220130/538eb44d/attachment-0001.html>