Why not more on 845 SETs?

Without first class transformers it won't matter how "good" the output tubes are. A well designed interstage coupled 300b or 211 SET amp sounds so much better than the capacitor coupled amps I've listened to I am sold on interstage tranny coupling.

The 300b SET interstage coupled amp being put together for me right now is so much better than my prior Audio Note Conqueror it is silly; another world. Parts cost on a four chassis 300b SET IS coupled is very expensive between 2000 and 4000 depending on transformers used (silver wound interstage run the price up about 2000).

Agreed, IT coupling is excellent. Cap coupling can be nice, but to be done right IMHO requires use of an excellent cap (read: russian teflon or better), AND requires grid chokes on both driver and output tube, and a good plate-load choke on driver tube. That done, it's basically like IT coupling in may ways (all the iron) except for the galvanic isolation (and any ratio/impedance change of course) of the IT.

Top-shelf iron (trannies, chokes, et al) are a must, in any case.

-Ed

And transformer prices are going up as is anything made out of metal....Price a set of six transformers from Electraprint, or Lundahl, for a single ended interstage coupled amp, then figure in the cost of a truly inert/non resonant chassis and the other parts and you'll quickly see why most quality 300b amps start around 4000 to the sky.

This is a good thread.
- In general 845 SETs are very expensive to build.
- It generates a lot of heat. Not good in summer.
- My main speakers are BSL Type II (102db).
- I use Bel Canto SET40 in Winter. It kicks major butt.
- I use Moth Si2A3 in Summer. Very sweet.
- I use Music Reference RM-10 time to time. Very fast.
- I've used 45, 2A3, 300b, 845 in SE, PSE and PP.
- When all things are equal 845SET is the King of SET.
- 845 will do everything 300b does and more.
- 45 and 2A3 are slightly better in the mid and high but much lacking in low.
- 845SET is sound stage champ.
- My other speakers are Melior One (87db). 845 will drive them.
- Output transformer is the most critical item in SET.
- MHO from MOE. So, don't shoot me.
- I have few more amps and motorcycles. Because, I'm only allowed have one wife.

Best regards...

Twl - Interesting posts. I know a guy who is doing something that should get the attention of all of us. He has a 24 wpc 845 SET amp on a pair of Spendor S3/5's. His listening room is small, and he doesn't want to disturb the neighbors. It's a crazy and simple setup, but it sounds amazing. Another interesting thing he done was to eliminate power bars and line filters. Since the amp is integrated and he only has one source, all he done was bought a Hubbell duplex outlet and installed it, and plugged both components right into the wall.