Supratek Tubes and Tube Swappin' for Everybody

Ray,
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You might even want to think in terms of 300 hours for full break-in plus your opportunity to really come to understand the sound with broken in tubes.
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I would also suggest only making one tube change at a time. This makes it a long process since you will have the break-in to go through with each set of tubes (assuming that they are new or NOS), but it is well worth it.
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Rgds,
Larry

Bwhite,
I'm surprised you can hear differences in Ken Rad 6SN7 of different prints. I've literally handled over 500 of these tubes in my lifetime and can't discern any differences. I'm also surprised you prefer their midrange to Tung Sols. I have always found the KR midrange subpar for a 6SN7.

As for my Supratek (line stage only):

6SN7: I use primarily Tung Sol round plates, although I do swap in Sylvania 6SN7Ws, Raytheon (flat plates), Sylvania VT-231 (also 52 Bad Boys), and RCA grey glass on occassion. I'd skip the CV181/ECC32 if I were you. It's one of those "midrange" only tubes with anemic bass and attenuated highs. Fact is, it was never designed for audio purposes (it's an oscillator tube).

regulator: Visseaux 6L6G or Mullard EL37. While I like what the 350B does for the midrange, they aren't my cup of tea for the rest of the audio spectrum. 6F6 tubes are too lean (and a bit edgy) for my tastes and my system. KT66 didn't float my boat either (bass was subpar, soundstage was collasped).

rectifier: Philips metal base GZ34. Defintely not muddy sounding, and far more open then the later production black base Mullards (which I agree are more lush and syrupy). I've never tried 6106/5Y3 in this position, but I'll give it a shot this weekend. I'm surprised it works well in a circuit designed for GZ34.

Disclaimer: this is all, of course, personal opinion based on my system only. For full disclosure, I should also state that I was (and still kind of am) a tube seller.

Bwhite, you are a genius.

I tried the 6106 months ago and I think I was the first to slam the tube for having weird timing. Didn't like it at all.

I took your advice and let it burn in for three days. Wham! This tube rocks. Clearly better than the venerable 5AR4/GZ34. No contest. I didn't realize the 5AR4 was muddy until I put the 6106 in. And the 3D palpability is much increased.

Once again, thanks for the inspiration to give this tube another try. It's now my reference rectifier.

Aloha Fiddler, that's great! So I'm not crazy after all? :) Hey.... I'm in Kauai right now... and I can almost hear how awesome your system sounds from here!

Aloha Brian,

If you can make it over to Maui, I would love to have you in as guests to my show. The only night I am dark is Sunday nights. Any other night its two shows per night. If you can't make it this trip, let me know next time you are headed this way.