your opinion: Will this power transformer handle it?

[Matt Syson]

Hi
The rating will be fine.
a valve heater would take the most power in this application and is a little under 2 watts (VA).
The circuit is pretty wasteful getting 6.3 volts from a 24 volt transformer but even so it is not a massive deal (maybe 8watts, I didn't read the whole article). Yes I know Watts are strictly speaking not the same a VA but it is close enough for this job.
Matt S

[brad347]

that is great news. In your opinion, do I need to move the lamp to the primary side and use a 120v lamp? I estimate the lamp draws about .3 amps.

[Matt Syson]

Hi
No you don't need to.
I would suggest using a 28 Volt bulb taken from the secondary of the transformer, with perhaps a small resistor as well so that it 'glows' rather than 'shines'. On the AC secondary you are not 'wasting' the smoothing which would be the case with using it at a DC point and the wiring will be at a 'safe' 24 volts rather than having more wires at 120 Volts.
If I were doing this project I would be tempted to put a regulator on the heater supply as they are so cheap and it would buy some 'insurance' against high mains input and give a more consistant performance. A LM317 variable regulator would be fine, as would a 6 volt version of the LM7806 or similar family. The extra parts would run to another Dollar or thereabouts.
Matt S

[brad347]

thanks a lot for the info. It all makes my life easier.

Anyone considering this project should try it. I'll be at less than $400 all in for the pair of mics and I used NOS Mullard tubes, Jensen transformers etc (quality stuff)

I am getting really good results.

Here's a test recording I did of various sources in an untreated room.

http://www.soundsdifferent.com/music/MXL_Test.mp3