the leisure to guess, comment and describe my supposed circuit with their jealousy, uglyness and denigration, in the absence of their knowledge... 
Thanks @azazello !
That said, due to extreme compacity (275 x 175 x 65mm for one chassis), there's a 3-speed fan cooling at the back, using a chimney effect around the 6080 :
Fortunately, the 1st speed is enough to maintain the chassis cold and limit the heat around the 6080 at a reasonable value...
The power output is 10WRMS on 16R, the onset of clipping being at 13-14WRMS. The bandwith is less than 1Hz to 250KHz. THD is circa 1.5 to 2% H2 at 10W.
A+!
Thanks @jim !
Yes, I find them very practical, reliable and cost effective. Another great point of interest to me is that it allow the building of compact amps. I used these ones :
Hammond 1550J :: Diecast Aluminum :: Enclosures Boxes :: Electronic Parts :: Banzai Music GmbH
Parts placement :
Tracing and drilling :
Engine turning :
Pre-assembly :
A+!
Very nice amp congrats, I have a question, what would be the outcome of a failure on one tube to the speaker ? ...all the best
Thanks @kissabout2002 !
Nearly nothing on a true OTL SEPP circuit - and by the way nothing dangerous for a speaker : at worse of the worse, 0.5 to 1VDC offset voltage, that can be easily identified. Remember that 1WRMS on 8R represents 2.83V...
A+!
Not in speaker output on mine, but on the plate voltage going to the 6080 - see the faceplates below (+115V and -115V fuses) :
A+!
