They work well enough, but I've cracked them drilling the M2.5 holes out to M3 for mounting LOL. I use them in the amp I built in a cake pan though...
You got a current production item. Svetlana went out of business some years ago and you need to get NOS on eBay or elsewhere. The tube you purchased is actually made by Expo Pul and is part of Mike Matthew's pantheon of brands - nothing at all to do with the original Svetlana Spb. (Look for tubes with the winged C symbol on them if you want genuine Svetlana tubes.)
Your chance of getting one that matches closely is pretty low so buy more than 1.
Svetlana
Thank you Kevin
Winged Cs went through the roof. I wouldn’t even think of putting one into this time-bomb)))). All of mine are not winged C. Will look for something similar. What about Electro Harmonics? Are the new ones also very different?
Thank you Kevin
Winged Cs went through the roof. I wouldn’t even think of putting one into this time-bomb)))). All of mine are not winged C. Will look for something similar. What about Electro Harmonics? Are the new ones also very different?
The winged C are the originals, if you want any chance of matching that's what you would need. The tubes developed and sold by SED are the tubes later sold under the winged C brand name.
My experience with Shuguang in applications like this has been bad, I'd stay away even though the price is attractive.
The best grade of KT88 (Mullard) made by New Sensor (Expo Pul) have been OK in my experience. (Buy matched and burned in from someone like Jim McShane)
Hello from Greece! I think better and very good sounding tube is the JJ KT88.I use these tubes in my diy SE amp,in very hot bias(Vak 370v,Ia=95ma UL 2,5k opt). No problems at all,very good sound ,steady bias,about 6 months every day use. I read here no good comments from these tubes,maybe i am lucky! I buy these tubes from ebay before 6 years ,4 pieces,from Austrian seller.It is matched perfectly about -+ 1.5ma.At the first do not use them,but after tube rolling and some tube failures i use them.I test many tubes in these amp.At the first plug in shuguang kt88-98. Very good sounding tubes,but after a few months no good treble,and slow bass,and i have thermal runaway in one tube.and a few days in the other! Game over after 2 months! One friend gave me to test shuguang 6550-98.Almost same sound as kt88-98,but overheated and redplated,no good. After i buy the new super tube Kt120. Very good sound with extra bass and dry mids and not so good highs. I use these tubes for about 6 months,and the getters fading fast! After all i use JJ KT88 ,almost same bass as kt120,and little hard mids in first 80 hours. Now sound is perfect,is more warm more tubey i think. I recommend,these tubes,excellent for the price,very strong mechanically,and electrically,no hum no hiss,no drift,almost perfect
That's fair. FWIW I found they hold up better than new Tung SOL 6550 though. I was really surprised how fast the modern "reissues" die. Not that I was running the tubes conservatively, but the getter flash all but disappeared within 2 months of 24/7 operation at 400V, 70mA triode mode...
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the old tubes of yesteryears used cathode materials that are doubtful exist today, i think that is where the difference is, i could be wrong, i read it posted by a tube guru years ago...
You might be right. The move for less toxic materials (think RHOS) has led to a reduction in simple materials that industry used to use.
My favourite tubes aren't still made as far as I know (6P36, 6P45 etc.) but they had kick asss cathodes, no?
My favourite tubes aren't still made as far as I know (6P36, 6P45 etc.) but they had kick asss cathodes, no?
i have the 4D32., QE08-200, power tubes to try...
the 829b/5894/832, they are nice sounding tubes that i have made an amp with..
lots of TV scanning tubes, the 12EN6 pp amp i made was even chosen over the 6bq5 tubes in the same configuration...the 6lu8 pp amm, the 13fm7 amps are very good sounding
smoking-amp tested a lot of horizontal scanning tubes and came up with a ranking, guess what? the lowliest of the TV scanning tubes beat the usual audio power tubes in terms of cathode capability...
the 829b/5894/832, they are nice sounding tubes that i have made an amp with..
lots of TV scanning tubes, the 12EN6 pp amp i made was even chosen over the 6bq5 tubes in the same configuration...the 6lu8 pp amm, the 13fm7 amps are very good sounding
smoking-amp tested a lot of horizontal scanning tubes and came up with a ranking, guess what? the lowliest of the TV scanning tubes beat the usual audio power tubes in terms of cathode capability...
I made an amp with those (the Soviet equivalent anyway) and it sounded pretty good... Both halves in parallel as a PP amp (four tubes) into a ~5k load... 400V B+, 200V screens...
Sweep tube cathodes == LOTS of current if you need it. That's the basis of my amp designs. You really can get 100W out of a pair of 6P45S connected as triodes in AB1 operation (with interleaved setup, 12R DCR primary). Still, two pair in parallel give long life and lower distortion.
Sweep tube cathodes == LOTS of current if you need it. That's the basis of my amp designs. You really can get 100W out of a pair of 6P45S connected as triodes in AB1 operation (with interleaved setup, 12R DCR primary). Still, two pair in parallel give long life and lower distortion.
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well, that is what the diy audiophool crowds are missing, their loss....
high power at not so heroic voltages, what is not to like?
high power at not so heroic voltages, what is not to like?
The Japanese Omron are a direct clone of a highly rated US socket (forgot which ones, may have been Amperex, not sure, memory is hazy after heart surgery). I bought 8 of these 3 years ago and I just checked and they are bakelite and rated for 10A per pin.
They were not a perfect fit for the PCB and I found 12 Cinch of which I have 4 left. I also used Cinch for the 12AX7 and am going to use three of my last four for my new amp.
Tubes
Thank you
What about Electro Harmonics? Same manufacturer? There is one single Svetlana tube on ebay right now, dated 2000. It has 45 degree angles getters like mine, but Square holes instead of round like mine. I wonder. Every winged C I’ve seen on ebay has getters that fire upwards. I guess I may have to sell mine and buy 12 new ones.
Thank you
What about Electro Harmonics? Same manufacturer? There is one single Svetlana tube on ebay right now, dated 2000. It has 45 degree angles getters like mine, but Square holes instead of round like mine. I wonder. Every winged C I’ve seen on ebay has getters that fire upwards. I guess I may have to sell mine and buy 12 new ones.
JJ
Thank you
It’s a possibility. My amp has 485v B+, bias around 25 mA. I have to do some more research into these JJ
Thank you
It’s a possibility. My amp has 485v B+, bias around 25 mA. I have to do some more research into these JJ
Reflecting on your problem - I once had an amplifier that had some parasitic oscillation when driven iand only in only one tube. Fine without drive. Basically bad design and bad wiring. Wonder if it is your case here - unfortunately an old cathode ray oscilloscope is one of the better things to use to discover it, personally i have not had much luck with a digital scope for this.
Thank you Amadeus. It is possible. When you say “only when driven”, what do you mean? It was fine at idle with no load?
485vdc x 25mA is roughly 12 watts per tube, you are running them cool..about 35% of plate ratings..
i have yet to make an OPT with that kind of primary dc resistance....but i will get there eventually...