Al's pseudo-C800/G7 mic idea...

Gus · Apr 6, 2005

Al I was not offended. Marik posted what I kind of was thinking. Maybe the best way is to built a reg and unreg supply for the B+.

The diodes in the fil supply and caps used seem to make more of a difference to my ears than doing the math would seem to show. I reg the fil supply with big caps and a 3 term.
I think it has to do with the turn on and off parts of the Si diodes causing spikes. I seem to hear more "noise" from the fil than the B+ in some microphones I have built

alk509 · Apr 6, 2005

Thanks, Gus! I certainly recognize your experience and appreciate your comments. The last thing I'd want would be to come off sounding like a prick :wink:...

I'm going to try an unregulated B+ supply and A/B the two, then maybe even post some soundclips on the web...

...But I'm getting ahead of myself! I've been doing some reading about diode switching noise and now I'm curious to see what some different diodes would do... Ill report back!

Thanks again, everyone!

Peace,
Al.

BradAvenson · Apr 7, 2005

One thing good about a regulated supply is that if you set the capsule polarization voltage with a voltage divider, it is much more consistant.

You could just regulate the polarization voltage with something like this though:
http://www.supertex.com/pdf/datasheets/LR12.pdf
100v input max
http://www.supertex.com/pdf/datasheets/LR8.pdf
450 V input max

Most of the tube mics I have made use regulated supplies, so I don't really have any good comparisons. How much line variation is there?

Marik · Apr 8, 2005

[quote author="alk509"][quote author="Marik"]
See, I'm a little conflicted with this, precisely because of what you say about SS-vs.-tubes. But the thing is I just LOVE these TL783 ICs. I've replaced the RC power supplies on three different boxes (an LA2A-type compressor, and two mic pres), and the sound just comes alive!
[/quote]

Yeah, different circuits "react" differently. I made a lot of comparisons between both, regulated and unregulated, and to my ears no-global-negative-feedback amplifiers sound better with unregulated PSU, which makes sense, at least to me.

alk509 · Apr 8, 2005

[quote author="BradAvenson"]You could just regulate the polarization voltage with something like this[/quote]

Hmmm... Those can't handle much current, but they should be fine for biasing the capsule.

Anyone tried them?

Thanks Brad!

Peace,
Al.