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KT88 power tubes, please share your experience

post #1 of 16
Thread Starter 
Looking for some comments about the quality of differ KT88 valves sound

Anyway, found these KT88 DIAMOND Tube Valve - - - EUROAUDIOTEAM - -, modern production EAT KT88 Diamond valves, which are very expensive that goes for like EUR 960 for a matched quad or EUR 450 matched pair, so, getting 2x matched pairs seems to be cheaper, cos of less hand work, I guess...
I am also interesting in any comment about GEC KT88 UK made tubes or any other modern / NOS KT88 please.
Lets make a list of amps, tubes combinations and speakers been used with possible description of the results, just put as much as you can here, even the music you are listening/prefer.

THX

p.s. Pics are always welcome, but think of re-size, before posting them please.
post #2 of 16
Quote:
Originally Posted by Blackmore View Post
Looking fo some comments about the quality of differ KT88 valves sound

Anyway, found these KT88 DIAMOND Tube Valve - - - EUROAUDIOTEAM - -, modern production EAT KT88 Diamond valves, which are very expensieve that goes for like EUR 960 for a matched quad or EUR 450 matched pair, so, getting 2x matched pairs seems to be cheaper, cos of less hand work, I guess...
I am also interesting in any comment about GEC KT88 UK made tubes or any other modern / NOS KT88 please.
Lets make a list of amps, tubes combinations and speakers been used with possible description of the results, just put as much as you can here, even the music you are listening/prefer.

THX

p.s. Pics are always welcome, but think of re-size, befor posting them please.
I compared KT88 from Svetlana, JJ and Elektroharmonix and found Svetlana (with =C= logo) to be the best. I exchanged them on Bewitch PP amp. Saying that, I must admit that far greater changes I got when I exchanged the driver tubes. The impact of different driving tubes was much larger than when I exchanged the output KT88's.

I performed these tests when KT88's were driven in triode mode.
post #3 of 16
Thread Starter 
Thank you for sharing. Have you ever tried/compared any other brands such as GEC.
And yes, I do know that pre section tubes, which in my situation are 2x 12AX7 and 2X 12AU7 having quite influence to the sound sig. At the moment I use 4x NOS 6550 Tung Sols instead of my stock KT88 and the changes were significant. Not that sotck are bad, they just quite different.

THX
post #4 of 16
I do not have experience with GEC KT88. Worth trying though ... Genelex (Golden Lion) KT88 are must try and they are considered as one of the best KT88- even this new stock. EAT are very interesting as well but because of their price they will remain "out of radar" for many of us ...
post #5 of 16
Thread Starter 

GEC KT88 valves

O.k. here they are, so, if anyone could tell me the production year of these 2 pairs, would really appreciate this.

THX

nr1



nr2
post #6 of 16
For modern run KT-88 my first choice would be the Genelex (Golden Lion) KT88 which seem to be better all round for low, mid and highs compared to others and better balanced SQ, my second choice would be the JJ blue glass:



post #7 of 16
Few months ago on polish website High Fidelity (nice polish name, isn’t it?), was done KT-88 test including Svetlana, Golden Lion, Electro Harmonix and EAT. In short words, in the best order:

1. EAT.
The best from four. No doubt. Very detailed but also very rich and slightly heat sound. Fantastically stepped dynamic. Silky highs. Very deep bass.

2. Electro Harmonix
Dynamic and realistic sound, but not as subtle and full-up.

3. Golden Lion
Very deep and “gold” signature sound, but not as good controlled like this Harmonix one. Beautiful sound out.

4. Svetlana branded McIntosh.
Muffed sound. Out of quality. How could McIntosh use such poor tubes?


This is not my opinion. I personally know only KT-88 Electro Harmonix with Leben’s amplifiers. They are really realistic, but slightly sharp. Very good for K701, but not for K1000. With GS-1000 simply disaster.


http://www.highfidelity.pl/artykuly/0902/kts1.html
post #8 of 16
EAT's are a bit over priced. I would change the driver tubes first and the major gains in SQ will come from the drivers first.
post #9 of 16
Thread Starter 
I did that and found the sound I like, but, my amp was designed based on KT88 and not 6550 or others he can use. Thats why I would like to know what ever GEC KT88 are worth to upgrade or not, cos I dont know how they sounds like. They suppose to be great tubes, but so are the TungSols 6550.

Quote:
Originally Posted by Stevesebastianb View Post
EAT's are a bit over priced. I would change the driver tubes first and the major gains in SQ will come from the drivers first.
post #10 of 16
I have a DIY single-ended electrostatic amp that uses kt88/6550. The original GEC kt88 are better than any of the modern production. Original Tungsol 6550 are in the same league. Expensive, but considerably cheaper and more available than the GEC kt88. For modern production, the Gold Lions are pretty good, but a definite step down from the originals. I'm not impressed with the Chinese versions I've heard.
post #11 of 16
Thread Starter 
Thanks for your input. Just one question please. How would you describe the sonics of GEC KT88 vs 6550 TS. Not sure why, but have some feeling that GEC may have better balance and bit warmer touch. I do have NOS 6550 TS, pair of black plated and pair of grey. Would appreciate any impressions.

THX

Quote:
Originally Posted by FrankCooter View Post
I have a DIY single-ended electrostatic amp that uses kt88/6550. The original GEC kt88 are better than any of the modern production. Original Tungsol 6550 are in the same league. Expensive, but considerably cheaper and more available than the GEC kt88. For modern production, the Gold Lions are pretty good, but a definite step down from the originals. I'm not impressed with the Chinese versions I've heard.
post #12 of 16
My speaker amp uses KT88/6550 and I did quite a lot of tube rolling when I first got it a number of years ago. In my Conrad Johnson Premier 140 I tried;

Svet-6550 (flying C)& KT88
JJ KT88
new production Tung-Sol 6550
Electro Harmonics KT88 (KT88EH)
Early Valve Art KT88

On various other amps I've listened to the new production Gold Lion KT88 as well as the NOS, Tung-Sol 6550 NOS solid gray plate, GE 6550 and the Penta Labs GEC copy.

In my system I currently run the KT88EH but when I get around to it, I'll get the new Gold Lions I think. This is pending hearing the Black Treasure KT88's.

I agree with Frank regarding the superior sound of the original GEC and Tung-Sols. I don't think that the new GL's are really that far behind the originals but on some gear, the Tung-Sol solid plates are just heaven.

For lower price options the EH's couldn't be touched in my system and listening preferences. Part of that was because my listening room at the time had a floor that flexed like crazy (renting). The EH's are lacking in the bottom octave and it was just what I needed to keep the room from booming like crazy.
Because of things like this, you'll get some folks that'll say they love an output tube and just as many who'll say they hate them. The only way to tell is try them in your own system.
post #13 of 16
Thread Starter 
Thanks guys, I may stick with my NOS TungSols 6550 after all.
post #14 of 16

kt88 tubes

nice looking kt88 tubes, first pair 1966 week 5 second pair 1970 week 28. How do they sound?

Rojo55
post #15 of 16
Thread Starter 
yes, they are, but unfortunately I was late to buy them, however bought some quad later anyway and the sound is superb, they eat stock Chinees made Genalex for breakfast, even concider their price tag.
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