Dennis Had Inspire amps and preamps.

Wolf--Pretty sure your "raving," at least subconsciously, influenced my decision to pull the trigger on it.  I bought my amp lightly used.  It came with GL KT88s, a vintage RCA 5u4g, and a metal base 6sn7w(!).  I've read that Mr. Had pretty much built these to be able to take just about any tube that will fit.  But, I'm afraid to just start changing without knowing.  I'm pretty sure KT77, 6l6, 6ca7, 6550c, kt90, el34, kt90, kt99, kt66, kt120, and kt150 work, but not sure if the rectifier needs to change with the power tubes.  The kt150 is supposed to kick up an extra watt.  It's the one that's supposed to do 17 watts with KT88 and 18 with kt150 (with the big square output transformers).  Can't imagine the tubes last very long burning that hotly, so need to at least have some spares ready.  It sounds great as is, and I imagine the prior owner took some time to roll to the specific tubes.  No "need" to change, but sure wanna try it.

I have a bunch of 6sn7s, but no Amperex.  Maybe I'll hunt one down.

Just for fun, I hooked it up to a pair of power hungry Salks, and it actually sounded good--at conversational level.  It lost its mojo at a reasonable listening level.  It's the best sounding amp that I've tried with Omega 3 HO, even better than with much more expensive PSETs.  It also sounded really good with Sophia Princess Model 2 (88db).  It's a small carpeted room, for now.  Basically taking over the guest room with gear and disrupting domestic tranquility.


John:  How do you like your SLP98?  I have a red one and really like it, but it does this weird thing--as I turn it up to rockin' levels, the singer gets larger and larger--not that the singer gets closer or louder, just larger and takes up more space.  Weird.  Swapping things in and out, I've narrowed it to the SLP98.  That's my only criticism of it.

The 3,987 posts (true…likely more once I finish this post) on the Audioaficianado site are a treasure trove of info in this amp (and the preamps). The GZ34 and 274B rectifiers allow less "voltage drop" so seem to drive the 88s and similar tubes with more gusto. The Sonist speakers when compared to my Silverlines are somewhat reticent in the treble, and I'm swapping out resistors in the Sonists to fix that…we'll see…it might be some sort of system synergy issue, but it is kind of a drag as I really wanted to like the beautiful Sonists, but the Silverlines, although less efficient, seem efficient enough and have never sounded better…I was surprised when I put these back in my system at how utterly revealing and clear they sound at any level I need. I'm considering a pair of Klipsch Heresy IIIs as an experiment in efficiency since they're relatively inexpensive…but in no hurry as my system is working so well. There's an AE-3 DJH Dennis Had preamp with remote at a local shop that's interesting to me as the current Inspire preamps lack remote control…also the Shiit Freya seems like fun and I like the balanced bits (my current preamp is a dual mono SS balanced beast with isolated power supplies made by Kavent as a rebadged Vincent…strange but true).

Intuitively you’d think that the Sonist is the better speaker match for the Had amplifier due to its specifications. The Silverline Prelude apparently must present a gentle and easy load in order for this amplifier to excel to such an extent. It will be interesting to see if swapping resistors in the Sonist makes an appreciable improvement. The Had amplifier must possess a pretty respectable power supply and output transformer for it to preform this well.
Charles

Hello all,

This tube was never made by Amperex. ALL Amperex tubes on the market are Russian relabels. The Ameperex tube looked suspiciously like a Sovtek, right down to the 'flying saucer' getter. Amperex catalogs have been checked and verified to prove that Amperex never made a 6SN7 tube of any kind.


Amperex 6SN7GTB
These tubes are likely Russian-made. Be wary of overpaying for them!
Base: black
Glass: clear, orange Amperex labeling with globe logo, may have white ‘6SN7GTB’ labeling
Plates: grey, T-plates
Getter: bottom, ‘flying saucer’ getter holder, flashing extends a little bit past base, usually more so on one side
Top mica: rectangular, has ‘spring-loading’ for plates (U-shaped structures)
Other significant features: bottom mica identical to top mica. micas appear whitish. 2 support rods on either side between both micas.

I have seen a couple of these over the years either gt or gtb and both were just relabeled Russian made tubes.

I recall just ok sounding,nothing like early Slyvania's and Tung Sol's
IMO.

Kenny.

Amperex labeled tubes were made in both Hicksville and Brooklyn. Look it up.

And although the Sonists are a couple of DB more efficient, the Preludes have a certain something that just sparkles…I was surprised really, but haven't given up on the Sonists yet…more resistors are goin' in!