John Curl's Blowtorch preamplifier part II

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I also now see that the larger diaphragms actually have higher inherent S/N ratios, I would have thought the opposite.
Are-you sure ? I would had though they produce more level at the membrane output for the same signal than smaller membrane's one.
Addition of 3dB of noise per unity of surface, and 6dB of signal, no ? So an increase of 3dB of signal noise ratio when twice the surface.
 
Esperado,
I'll have to go back and read that, I took that to mean that the output signal level was rising at a faster rate than the noise? I see Scott's comment also, I will read it again and see how I misconstrued that.

George,
It's not fair, Greek and Latin are the base for all these words, you have an unfair advantage! English is just meant to confuse. To, Two and too.
 
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"I could have been a judge, but I didn't have the Latin"

Perhaps the audio community should start conversing in Latin. I'd like to see "love (or hatred) of double-blind testing" translated.

When my late father had suffered from a peripheral neuropathy that was both excruciating and ultimately crippling, I would speak to him frequently by telephone. One day he was cheered somewhat, saying that Well they finally figured out what the hell I have, and pronounced two Latinate words.

The diagnosis was, I suspect, little more than a vague localization of the regions of inflammation, and did not lead to more specific treatments or pain reduction. But for him it sounded scientific, and he prided himself on being scientific---despite his world view being mechanistic, at best based on 19th century physics. He also persisted in imagining some growth somewhere in his body that caused the pain. When he considered acupuncture, I thought it was something of a breakthrough for him, a possible countenancing of some alternative medicine---whether it would have helped or not I don't know. But he went on to say Yeah, they're gonna stick those needles in me, and find out where the hell this thing is, and then they can CUT IT OUT!
 
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Hi Canyoncruz,
It is the wrong place for sure.

Please try here : Swap Meet - diyAudio
If you look at the forum names, you will see other likely places to look.

As Kindhornman has kindly pointed out, there are thrift stores and garage sales to run through in your area. Don't forget the recycling depots and flea markets, although they can be pretty dear these days.

-Chris
 
Esperado,
I took that to mean that the output signal level was rising at a faster rate than the noise?
Just to help-you to understand, consider two microphones aside each other and mixed together. Their signal wiill be the same, (phase and level) So they will add their voltages: gain of 2, or 6dB.
Their noise are random. Not in phase together, so they will add statistically only+3dB (power X2). You have increased your signal/noise ratio by 3dB.
Quadruple your mikes, and you win 6db s/n etc...
 
Just to help-you to understand, consider two microphones aside each other and mixed together. Their signal wiill be the same, (phase and level) So they will add their voltages: gain of 2, or 6dB.
Their noise are random. Not in phase together, so they will add statistically only+3dB (power X2). You have increased your signal/noise ratio by 3dB.
Quadruple your mikes, and you win 6db s/n etc...

Yep, that is correct. Doubling the diaphragm area gives double the output, so a 6dB increase, and it also gives higher total noise (a larger area for air molecules to randomly hit), but the noise is uncorrelated so it only increases 3dB - so we get a total SNR increase of 3dB by doubling the diaphragm size.
 
Also, singers learn to work with proximity effects, and will gravitate to mic's that they're familiar with already. Just look how popular the SM58 remains for non-professionals, despite its definitely NOT hifi performance.

Folks show up to perform and need to think about other things than the mic. They want something that looks familiar. There's a term in evolutionary biology that covers the situation, but I can't recall it. "First guy on the scene wins." Vocal mics for speech look like EV-20's and vocal mics for singing look like U-47's. Can't be fixed anymore!

Thanks, as always,
Chris
 
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such a deal

Yep. I borrowed a mint pair of tubed U-47s from an employee of the family business. He had no idea what they were worth, and I was too honest not to tell him.

He had purchased them from a widow at a church yard sale, along with some FM mikes, stands, cables, and an Ampex luggable reel-to-reel. No one had been interested, so Glenn got them for

wait for it

10 dollars.

I managed to use them for a couple of chamber music concerts until the guy was laid off and got them back.
 
Also, singers....will gravitate to mic's that they're familiar with already. Just look how popular the SM58 remains for non-professionals, despite its definitely NOT hifi performance.
Folks show up to perform and need to think about other things than the mic. They want something that looks familiar. ....
...vocal mics for singing look like U-47's. Can't be fixed anymore!
Soooo true ;-)
I loved to use, long time ago, Sennheiser MD 441. Because it sounded nice on our PA systems, was solid, flat and very immune to larsen (Hyper-cardioid).
Such a fight with most of the singers that i gave-it up so often.
One advantage of this junk of SM58 on stage is you can use-it to knock in nails ;-)
 
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I loved to use, long time ago, Sennheiser MD 441. Because it sounded nice on our PA systems, was solid, flat and very immune to larsen (Hyper-cardioid).
Such a fight with most of the singers that i gave-it up so often.

Yes, I also would try to persuade singers to use better mics in my SR days. We had an EV-15 that I really liked, but it was a little beat-up looking and scared people. I considered it a mark of great trust for an experienced singer to use it in performance. Their total performance critically includes the mic, and I think most singers actually understand that better than most "sound guys" understand it.

Much thanks, as always,
Chris
 
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