tube upgrade for first sound


Has anyone been able to improve on the stock tubes in the First Sound preamps? I was thinking about trying the Russian 6H23. Any thoughts? thanks
84audio
ok. I'm finally done messin with NOS tubes. Man was that tiring. I must have tried 5 different tube sets before settling down on 2 - each time losing some $$.

Final all around winner: 1959 Amperex PQ "Pinched Waist" D-getter 6922 (US made). Smooth as silk, highly accurtae, with just a smidgeon of bloom. Notes have more defined and controlled beginning, middle and end. Delicate and forceful depending on material. a true champion. Example, the inner harmonics of Kind of Blue, at the opnening of track 2 "Freddy Freeloader" - where the trumpet and sax are playing similar notes - I've never before appreciated the lovely separation between them, yet it wasnt an artificial highligh, no - the tones and resonance of each individual instrument was nicely laid out, side by side, as they were intended to, as they would sound if you were there.... I wont even mention how much I paid for these.

Second Place: 1959 pearl cryo'd Phillips Miniwatt german made 6DJ8 (aka bugle boy). Creamy smooth and lustful presence. On some recordings (e.g., Lucinda Williams) the midrange presence and rock solid images are simply jaw-dropping. Music just flows. Not as clean, nt as refined, not as all around a winner, but on some material, it beats the PW 6922's.
Post removed 
well, they dont say bugle noy on them. they say Phillips Miniwatt, but as i understand it, they are the same as the "bugle boy." I think they are steel pin d-getters...
This thread is an absolute fountain of priceless info!!! Oldpet, could you tell us what are the two tube preamps you examined then discarded on your way to audio Nirvana with the First Sound. And where did these preamps fall short?
Guidocorona
Before I answer you, I just wanted to thank you for asking Emmanuel about the Hot Rod First Sound units. :-)

I decided to work my way up the price ladder. Keeping in mind the caveat of DC leakage.

The first stop along the way was the Tube Audio Designs "TAD-150" By Paul Gzrybek at Bizzy Bee. Paul is a gem to work with. We shipped the preamp back and forth 3 times for various tweaking. The first TAD-150 was completely stock. After the first go round the unit then became one of Paul's "signature" preamps. The 'stock' pre simply didn't have enough weight or depth for my taste. Especially in the bass dept. When the preamp was tweaked into the 'signature' series, the bass was greatly improved but, still just not enough weight for me. Keep in mind this preamp only costs $700! I would say that for many people this preamp could stop their search, right then and there. Needles to say. I ended up sending it back to Paul for my refund.

Next up was the SAS 10A by Steve Sammet. ($1995) A really outstanding Preamp. Dual mono in its construction etc. But, it was noisy in my system. The bass was just a small bit light from what I am accustomed to. I think if it had been quiet however, I could have stayed with it. But i thought - why compromise at this point? Back it went for the refund.

Both the TAD-150 and the SAS 10A did a beautiful job with vocals and staging.

Both Steve and Paul were easy to work with. They were fast with getting my refund back to me. Their business model is one I wish more Agon dealers would adopt - REFUND if you are not happy with their product.

So here I am, awaiting the arrival of hopefuly my last preamp - EVER! :-) This "trial" is MUCH more risky though, as I am NOT able to return it for a refund. :-( On the positive side - I think I've read only one, mildly negative comment, from someone who auditioned a F.S. and didn't find it to be his cup of tea. I basically purchased this pre based on reviews (professional) and threads I've read.

If this isn't the one - then a very new F.S. Presence Deluxe II will be on the 'GoN for a true tube lover.

Wish me luck. sorry for the long winded answer. :-)

Paul