The last Sovtek 5Y3 I purchased didn't drop squat for voltage, so I wound up with 475V+ on the plates and screens of a pair of JJ 6V6s. Tubes are still running strong more than a year later. Me thinks I got a relabeled 5AR4.
The Sovtek 5Y3GT is *NOT* a real 5Y3GT. It's a re-branded Russian 5Z4M, a Russian indirectly heated recto quite close to a 6106. B+ can be > 30 V higher than with a 5Y3GT.
The JJ 6V6S is a very robust critter rated at 500 V plate. No problemo at 475 V if dissipation is reasonable and screen dissipation is well handled.
I didn't get any evaluation samples of this tube; I decided to gamble that they would be good (based on JJ's reputation) and I went ahead and scored 250 pieces. Only TWO died during burn-in, and 3 more were rejected during QC and matching. Just for fun, I tried to kill the last tube in the batch - and I was *blown away* by the fact that I had to pull more
than SIXTY MILLIAMPS through the tube before the plates wouldturn red. I let the tube cook in this condition for nearly half an hour, whacking it occasionally with a nutdriver handle. It just wouldn't die - and after it had cooled off, I took a new set of readings on it and the plate current had only changed by one tenth of a milliamp. The only thing I could see that was wrong with the tube after I tried to torture it to death was that the logo burned off the glass. And here's the best part- these tubes sound GREAT! Easily the equal of the NOS Philips (above) and with a bit more bass response. No field reliability reports yet, but based on my assassination attempt, I'm not worried about 'em. Put a set in your Deluxe Reverb and run 'em HOT! Should be good for the Jim Kelley, too.
UPDATE 01/01/05 - These 6V6s are the toughest ever built. Period. I've sold tons of 'em since the last catalog, and I can't recall getting *any* of 'em back. This is the ruggedest 6V6 on the planet. I'm still selling through the initial large order I placed; when those are gone, the price will rise due to the dollar/euro rate. UPDATE 09/12/05 - The price has indeed risen, but not terribly much. These are still the best price/performance ratio 6V6s you can buy. All of my boutique amp builder customers have switched to this tube instead of the Electro-Harmonix 6V6EH. UPDATE 04/22/06 - I have about six hundred of these in service so far, and the failure rate is vanishingly small. This tube
is hard to kill, and it kicks ass. UPDATE 08/05/10 - If you're looking to beef up the low end in your single-speaker, low-power, open-backed combo amp (Fender Princeton Reverb, for instance) then this is the
one you want. If you want the classic American 6V6 tone with the sweet top end and the smooth breakup, go with the Tung-Sol. If you have a Champ or other single-endedsmall combo/practice amp, the JJ is a good choice.
David, actually it was as high as 678v. As far as sound I'm not sure as it was only in a test chassis with a dummy load . However, I like enough of what I saw to proceed.
