Oh!  My apologies ... I gave you the completely wrong impression.  I didn't mean at all that Lukasz was cold or unhelpful.  Quite the opposite, actually.  He was quick, direct, and extremely helpful in answering my initial questions about this amp.  (And by "initial," I mean those questions...

  I actually don't have any objection to the appearance at all.  The exterior looks fine to me ... a few tubes sticking out of a box with some cool adapters.  Right on.  It's what's been altered in the interior that has caused all of the curiosity (at least for me).   And that curiosity makes...

  I can try to speak to this -- at least from my personal perspective.  I have experience with good headphones, I'm looking for a (new) high quality amp, and I'm just coming to this thread now.  (Well, make that a few days ago when I jumped in to clear up -- to the best of my knowledge -- some...

  Is there some reason to think that the Owensboro plant under GE ownership (as indicated by the "188-5") was producing two distinct 6SN7GTs in 1950 (as indicated by the "0-35") -- that is, a "GE" version and a "Ken-Rad" version?  I think that this is highly unlikely.   Whatever the case...

  Actually, most Ken-Rad 6SN7s came out after GE acquired Ken-Rad.  So far as I know, the relevant "before and after" in connection with Ken-Rad 6SN7s has to do with plate positioning.  It's said that the earlier staggered plate tubes are superior to the later parallel plate tubes.  No one...

  I'm surprised that any Ken-Rad 6SN7 would be described that way.  What are yours, exactly?

  I've been searching online for a picture of the HP8 MKII with the 6SN7 sockets exposed.  No luck.  How are the keyway recesses oriented -- toward the front?  This will obviously have an impact on whether these adapters will fit.  I figure you've already considered this ... I guess I'm just...

  Note the (still somewhat underground?) movement of folks putting together "theater-esque" systems that feature loudspeakers that wouldn't be -- or wouldn't have been -- out of place in a professional (as opposed to a home) setting.  When I had much more space than I do now, I experimented...

  WRT "better amp and dac," if you can recommend something better than DragonFly Red that's plug-and-play with iPhone, I'm all ears!

  Of course I see the "no current production" point.  I wonder, though ... this seems not to have prevented builders from taking the plunge back in the early-90s and turning out 45, 2A3, 300B power amps before there was current production.  I'm pretty sure that I had a 45-based power amp about...

  I just posted (in a different thread) about listening to the HD600s, the HD650s, and the HD800s in one comparative listening session last week.  I described the HD650s as "veiled, congested, and foggy."  (Not to quote myself -- sorry -- but I'm looking for the right terminology as you are.)...

I had an interesting experience last week as the bug to upgrade my HD600s has started biting harder and harder.  I sat down with HD600s, HD650s, and HD800s (all well-broken-in) -- along with Trio Wanderer's recording of Haydn's piano trios nos. 39, 43-45.  (I wanted to limit myself during this...

I've been using a 76-based preamp for the last 15 years or so.  It's based on Bruce Berman's design as it appeared in Sound Practices #13.  Very simple ... one single-ended stage (1/2 6SN7) driving the 76 with cathode follower -- as I suppose the type 76 normally likes to see.   I've wondered...

I'm in the market for a new headphone amp, and I'm wondering if the opportunity to run a fully balanced system should be the deciding factor in my purchase decision.   My DAC outputs a balanced (as well as an unbalanced) analog signal; and my HD600s can obviously be re-cabled easily.  Here's...

Apologies if the 6SN7 issue of Vacuum Tube Valley has been linked in this thread already.  (I ran a few searches and didn't see it.  That said, 5672 posts is a lot of ground to cover...)   Eric Barbour's article, "6SN7: Driver of Choice," is wonderful ... pictures, history, taxonomy, listening...