HIFI tube amp

Well maybe not HIFI by todays standards but something like it.

My father wanted a small tube amp, so I built him this.
http://ghr.fi/kuvat/6v6hifiout.png

It has triode connected 6V6 push pull output stages that deliver 2.5W power. 5W might sound like too little power but it seems to be plenty with decent speakers in a 30 square meter/320 square feet room.

Schematic:
http://ghr.fi/kuvat/6v6hifi.pdf

I used output transformers from Toroidy and I'm pleasantly surprised how good they are. Without negative feedback the frequency response is -1dB at 20Hz and -1dB at 20kHz. With 20dB of negative feedback the frequency response is essentially flat from 20Hz to 20kHz. Also there seems to be no issues with stability with 20dB of negative feedback. I put a switch in the back so the negative feedback can be switched on or off. With 20dB negative feedback it needs 2.5V input voltage to get full power and without NFB 250mV.

Guts of the almost complete amplifier
http://ghr.fi/kuvat/6v6hifiin.png

nice cans man   

I like - the classics can never be neglected, and 6v6 pp triode and pentode are both so fine. And with all octals, even better.

I myself am doing a 6v6 that way at the moment, guitar amp style with 6sn7 pi and 5963 red can up front.

I like the making the nfb 'variable'  option to dial in a modest amount of crunch.

Or not. Fully clean and with the extended bandwidth, you can get some fine sound out 6v6 et al.

Looking forward to getting mine in the lounge with a 2x 8" speaker box ... before winter comes back around 

...  for pure sub 5W heaven and some really rockin' 10Wrms 

*like*

Nice!! that looks like a stereo Fender tweed deluxe, with just a input tube missing. With a triode/pentode switch this
could realy rock the house..

That came out great.  Nice work.