Chinese Fluke ... any good .?

[gaetan8888]

Hi Gaetan,

Brüel & Kjaer really did mean quality. I have a 2601 microphone amplifier sitting here. It looks complete, I haven't opened it up yet. Some day ...

-Chris

Hello Chris

My B&K 4145 mics capsules are unpolarised capacitor mic that needed a 200V polarisation voltage, but I don't have anymore the power supply/preamp buffer.

Would you have or know any schematics of transistors power supply/preamp buffer for my 4145 ?

Thank

Bye

Gaetan

[anatech]

Hi Gaetan,
Not off-hand. I haven't done any research on this.

The unit I have is a tube type unit I think. It may in fact have such a supply built inside. I could have a look for you. I don't know if you're interested in it.

A low noise 200 VDC supply is not hard to build either. I have some HV regulators I have designed that work well. Let me know if you want anything like that.

-Chris

[gaetan8888]

Originally Posted by anatech

Hi Gaetan,
Not off-hand. I haven't done any research on this.

The unit I have is a tube type unit I think. It may in fact have such a supply built inside. I could have a look for you. I don't know if you're interested in it.

A low noise 200 VDC supply is not hard to build either. I have some HV regulators I have designed that work well. Let me know if you want anything like that.

-Chris

Hello Chris

Now I remember, the 2601 was a tube microphone amplifier.

Yes a simple 200vdc reg would be usefull.

I've just found a circuit on the web, with different voltage it may work with my 4145 ?

Thank

Bye

Gaetan

[anatech]

Hi Gaetan,
No, let's do something a little better than that.

I'll try to find some diagrams for you and send them off. They work and I'll tell you what the performance is like along with the trade-offs I made when designing them. Hint: I go for low noise before tight conformance to a certain voltage. The changes in voltage occur as a slow drift to a final value that is really a temperature effect. Keep it cool and you get very little drift. These will all be things that exist in real life and have been working fine for some time now. My guess is almost zero current draw. Is there a tube amplifier stage in those mics?

If you're interested in the 2601, I'll trade for something - you cover shipping. I'm thinking that I am not that attached to it, but you might be. I'll send a photo to you.

-Chris