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I have a friend that likes music but probably can be considered a non-audiophile (not into all the jargon, the marketing hype, the tweaks etc) . Also, he is an engineer.
So he has built a number of speakers (really nice cabinet work, mirror matched veneers, nice drivers etc) for his Rotel system. He came over to my place to hear SETs/horns and really liked what he heard. But he absolutely HAD to in-room measure freq response to validate what he heard. He was pretty happy to see that the measurements were reasonably decent which supported his enjoyment of the system.

I went to his home to hear his newly finished speakers projects (Scanspeak drivers, ported floor standers and a set of book self 2-ways) and brought my Dave McGowen built, PP EL84 monoblocks over to his place to hear in his system. In general, the tube amps were more full sounding, much better sound stage, tonally more real sounding and less homogenized than the Rotel system (which was pretty decent in it's own right, just a bit dry, flat, uninvolving sounding in direct comparison to the tube amps). My friend described the tube amps as "more holographic". Since he is an engineer, we set up a switched A/B box and did quick comparisons (although we did not obsess over matched volume).

It was really interesting to see a technically savvy but non-audiophile person's first real experience with tubes. The bottom line is that he enjoyed them enough that he is considering purchasing a used tube amp (or building a kit). I suggested that he just use a well thought of schematic and build from scratch (he certainly has the skills) but he was concerned that the build would drag on forever.

Any suggestions for his reasonably efficient speakers (~89-90db)? My ~10w PP EL84 worked very well at the sound levels he listens too. On the commercial side, I was thinking about a used set of Quicksilver monoblocks. Any PP EL34 amp would probably be perfect. David'd DRD 300B monoblocks might actually work pretty well but are a bit out of his price range. His price range in <$1500.

What about the OddWatt kits? Complete choice of output tubes is nice... Broski has a good analysis of the circuit that suggests changing the first stage to a diff amp.

The Red Light District is also excellent, but no kits are available.

The Engineer's amp by Millett might be an excellent choice. Not just for the name, but: 1) PCB for $50, almost everything on it; flexibility of output tubes, transformers, etc. Ability to grow with needs and use cheap horizontal sweep output tubes and TV pentode input tubes.

http://www.diyaudio.com/forums/tubes-va ... esign.html

A favorite of mine is attached. Pick your output tubes. Granted, not a kit, but with Guy's CCS boards, the Millet PowerDrive boards and a Chinese pre-punched chassis, it should be pretty easy, especially with the building skills your friend (who I do hope joins our club) has already displayed.

Stuart

Thanks, the OddWatt looks like something he might consider. I wonder if there are any hardwired amps in his price range (<$1500)?

How about half that price (not including tubes)?

http://www.triodeelectronics.com/st70buildkit.html

Ding, Ding, Ding! We have a winner. That would be an excellent choice for him! Thanks.

Given the choice of driver (6AU6 vs EF86), which would you recommend? I read that a lot of EF86 are pretty microphonic?

6AU6s are a lot easier to come by, I have a bunch and could let some go cheap...

This is a possibility as well: http://www.triodeelectronics.com/diy35kit.html Cheaper with tubes than the ST70 kit w/o tubes...

Roscoe

_________________
I can explain it to you, but I can’t understand it for you.

If you are interested, I do have a DIYTube ST35 board (stereo PP EL84) that is assembled, plus Edcor power and output transformers and a choke. It needs a chassis to complete. The power supply and tube sockets are on the board, so the only thing needed is selecting either solid state or tube rectification (if a tube rectifier, needs a chassis mounted socket. I can let this go for cheap for someone to complete. I probably have around $400 in this, all the transformers and stuffed parts are new, never used. I just thought of this reading the posts, and it would help clear out projects I haven't finished.

This can be moved to the Trading Post if more appropriate.

David

I put up a listing and description in the Swap Meet folder, so please do not reply directing to this thread.

David

David, thanks but he ended up picking up a nice set of DIY PP EL34 monoblocks with Acro TO-300 OTs. They really worked well for his speakers, a great match-up.

Now I planted a seed on his head that perhaps an outboard DAC would sound better than just running music straight out of his laptop.