Jeremy Fix Single Ended 6SN7

Here we have an extremely unusual little single ended 6SN7 amplifier. This was designed and built by Jeremy Fix; a very talented scratch builder who sells his amps on eBay. His website can be found here.

I’ve never seen another amp that uses the 6SN7 as an output tube and it is really interesting to hear the differences in all of the brands and types. 6SN7 is certainly a rich tube type to pick through, and if you want to know just how a particular type of 6SN7 sounds, this is the amp for you. I’ve found my sweet spot for this one is a combination of Sylvania “bad boys” and RCA grey glass, but NOS Soviet 1578 porthole plate tubes were very good too.

At around two watts, I’ve found it needs a bit of preamp gain to play really well on most speakers. That said, the sound here is exceptional. Female vocals in particular are really great with this amp; very much in the room and “live”. The soundstage is amazing too, and is easily one of the best I have heard. This diminutive little amp that has put several much higher priced pieces of equipment to shame.

The circuit is very simple, with only a few very high quality parts.

The output transformers are Telefunken and the power transformer is a vintage Stancor unit. As with all of Jeremy’s amplifiers (and I own two of his hi-fi units and a guitar amp), the built quality here is tremendous.