Simple 6BM8 at Evolve Power Amps?

[amt]

Hi,

Ive finally started on a Mullard design, suggested here some time ago, and found this while surfing 6BM8 info. This little amp looks very simple and the schematics and layout are very DIY friendly. I bablefished the page but it only did about half and unfortunately, Japanese doent translate very well.

Anyone know anything about this design and if it appears that Tango transfos must be used?

http://www.ne.jp/asahi/evo/amp/6bm8z/report.htm


amt

[Fuling]

Looking at the schematic, I find it more weird than simple I must say. What´s that transistor doing there?

I don´t think Tangos *must* be used, I´ve succesfully used this tube together with many different OPT´s between 5 and 10k primary impedance.

[Tube_Dude]

Originally posted by Fuling
Looking at the schematic, I find it more weird than simple I must say. What´s that transistor doing there?

The transistor is the first gain stage...of course a strange design option...

Or maybe the "best of both worlds"

[SHiFTY]

You need decent quality output transformers if you want a good sound. Power tranny you can use whatever you can get (for a small tube like this!)

I built the Mullard circuit with NFB and it sounded fine and had plenty of power.

[Original Burnedfingers]

I'll try to post the schematic

[Original Burnedfingers]

It says file to big. No can do

[fdegrove]

Hi Joe,

If you like you can send it to me, I'll resize it and post it.

Cheers,

[amt]

"Super triode circuits" seem to be very popular is Japan. From what I can gather, they have a Gainclone type of following in that its a new way to utilize commonly available parts.
I wonder how the circuit actually sounds compared to the norm.

And how does a Mullard w/ NFB sound in contrast to the original design? Id like to see ShiFtYs design so I hope it can be posted.

amt

[AKSA]

I've not heard any of the Evolve circuits from Kamijo, but I must say that his huge design repertoire and left field topologies are simply breathtaking. I suspect the man is something of a genius; rarely have I seen anything so original.

He does an EL86 SEPP circuit which I think is seminal, using a triode as a voltage divider - signal into plate, output from cathode - to scale down the negative feedback. And the way in which the two complementary transistors are used for voltage amplification in Rush cascode is astonishing.

His body of work is enormous, and would have taken a lesser man a lifetime of grinding hard work. Not even Julius Futterman matches this range.

Even his presentation, those sumptous drawings, is exceptional. Moreover, he never rhapsodizes about the sound, he simply presents the distortion figures, artefact by artefact, and quietly states that it sounds good. Hell, if he was a politician, I'd vote for him......

Cheers,

Hugh

[Original Burnedfingers]

schematic