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New Tubes- Need Burn-In?

Hey guys- a question.

I just put a new matched quad of Electro Harmonix KT-88EH in my Cayin A-88T Integrated. I properly biased the amp, and after a couple of hours of warm up there is still a touch of "glare" or hardness evident.

I know these brand new tubes need time to burn in...how long a wait is reasonable before I decide whether the EH tubes are the ticket or not? Any tips on what to expect?

Thanks!
danlib1
sogood51
2,157 posts
 
I installed new EH-KT88's in my Rogue amps (got them from Rogue)...they sounded good from the start, no glare at all?

Dave
newbee
4,798 posts
 
You must differentiate between SED's and Svetlana's.

Present day Svetlana's are nothing more than Sovteks in disguise. The really good Svetlana tubes are now called SED and they are made in St Petersburg. The logo on the tube is a 'flying C'. The change over took place several years ago so before buying "Svetlana" tubes investigate.

I use, on different amps, SED KT88's, 6550's, and EL34's and highly recommend them for their tone and ruggedness (I've never had one fail, yet).

I give any power tube 48 hours or so of break in before making a final judgment.
stevecham
3,340 posts
 
Ditto positive comments on the SEDs, especially the EL34s. Running a new quartet of these in a CJ CAV50 and they have all the extension and soundstaging I could ask for. Inner details and quiet backgrounds they do in spades, exactly what I was looking for. Likely one of the best brands of current issue EL34s for audio.
danlib1 OP
819 posts
 
Well guys, based on the feedback thus far I believe I'll buy a quad of SED "Winged C" Svetlana. Question is- should I try 6550 or KT-88 in the Cayin A-88T.

Opinions welcome!
newbee
4,798 posts
 
Don't know about a Cayin - probably depends on the sound you are after. You will likely hear a fuller and warmer sound with the KT88's and a more linear sound with the 6550's. I'm running KT88's with EH drivers in one amp and 6550's and EI drivers in another. Both sound great in that combination. So, once you pick your power tube consider how it will sound with the driver tube - makes a considerable difference.
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