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Mike Rivers[_2_] Mike Rivers[_2_] is offline
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Default Does anybody sell pre-made resistor "gizmos" for sm57/58 mics?

On 9/15/2020 2:45 PM, slinkp wrote:

It took some poking on archive.org but I found the article.
It was a UA 610 preamp, did he design those? (Honest question I have no idea)


No, Paul didn't design the UA 610. My recollection was that they
performed this experiment with a preamp that Paul called Project-R,
which was published as a DIY project in a multi-part article in
Recording Magazine, back when people would build relatively complex
gadget like that preamp.

Anyway, thanks for the link to the article.

https://web.archive.org/web/20171123...etail/330.html


Apparently the 610 has a nominal input impedance of 2k according to the article. My Focusrite Scarlett 2i2 is even higher at 3k.
By his formula, 600 ohms would work for me: 1 / (1/500 - 1/3000) = 600


That makes sense. The closest standard 10% value to 600 ohms is 610 ohms
- close enough, particularly since you don't know exactly what the
preamp's input impedance is, exactaly, and and at what frequency that
was measured. The idea is just to get close to a 500 ohm load across the
mic.

Oh, and as to Roy's offer - there's nothing wrong with using a pair of
XLR's with a short piece of cable between them. Just be sure you mark
the cable so you'll know what it is when you dig it out of your junk
cable box 20 years from now.

Oh, qne the genuine Male-Female barrel is the Switchcraft S3FM:

ttps://www.markertek.com/product/s3fm/switchcraft-s3fm-xlf-xlm-unwired-feed-thru-audio-adapter.


Roy's $10 offer is a better deal.


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