diytube.com

Very nice, and very creative design! I've considered the use of parallel-connected 6MD8s in a single-ended low-powered amplifier.

6MD8 is equivalent to three 12BH7A or 6GU7 triode sections. Three triodes in parallel would give a plate resistance of 1,833 Ohms, and a gm of 9.3 mA/V,
and voltage gain of 17.

Plan B would be to use 6350s connected in parallel, as I have a large quantity of these tubes.

http://frank.pocnet.net/sheets/079/6/6350.pdf


/ed B

This thread is useless withou a text ...

I like this kind of projects: find a useful but rather unexpected chassis and install a nice amp!

The OP tranny looks a bit like the ones I ordered från AliExpress:
http://www.aliexpress.com/item/Tube-amplifier-cattle-output-transformer-tube-amplifier-transformer-single-cattle/836254714.html

I was starting to figure out the circuitry from the close-up photos, but decide that there had to be an simpler, easier method

I then performed a little Internet Sleuthing, and, as Paul Harvey would say, here is the rest of the story:

http://classmate.glmed.com/fff/6md8/6md81.jpg



When you expand it (click +) it gives a large size schematic.

From what I found on the DIYAudio website, B+ voltage is approx. 285VDC,output power 6W per channel. Cathode current 12.8V / 510 ohms, approx. 25.1 mA per 6MD8, so they are being run fairly gently, at about 7W total PD per tube. No NFB loop.

http://www.diyaudio.com/forums/tubes-va ... e-amp.html