New Tubes- Need Burn-In?

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.

I bought a quad of EH 88's for JOR the other day. What an absolute waste of money, thank god the seller refunded almost all my $100. Not even close to the stock KT90's. The Jadis guy said it would cost me like $800 to get a quad of Jadis 88's.
btw Dan how is the bass in the Cayin A88?

Well, after much experimentation and help from all you guys I believe I have whipped the Cayin into line. Damn it's sounding good now!

My take on the amp:

The stock tubes are marginal at best- which is surprising considering the glowing reviews the amp has received.

The EH KT-88's I bought to try are too "edgy" in that amp- detail is good but everything has a noticeable level of attack.

I now have a quad of Svetlana "Winged C" KT-88's from Upscale Audio that were thoroughy tested and matched. I also replaced the Chinese 6SN7's with 2 NOS Sylvania 6SN7W's.

Man- it's like night and day- an altogether different amp. Great transparency, liquid vocals, in the room realism with good material, and better bass than I had with either the Cary SLI-80 Signature or the Manley Shrimp/Conrad Johnson MV-60 combo.

My final touch comes next week when I receive my NOS RCA Red Base 6SL7's to replace the 2 remaining Chinese driver tubes.

I'll report back after that move!

Dan I have plans to get the A88, months off though. What did you pay for the Svet quads? And the 2 sets of pres? Why did you use 2 different types of pres? Different #'s?
I may replace the tubes in my Cayin cdp if that will make a difference.. Any help appreciated.

Bartokfan-

I paid $170.00 for the Quad of Svetlana Winged C KT-88's from Kevin Deal at Upscale Audio. Yeah, I could have bought them cheaper, but I wanted a thouroughly tested and matched Quad.

The Sylvania 6SN7W's replaced the two Chinese 6SN7's that came in the Cayin. The Cayin also employs 2 6SL7's, which is where I'll stick the RCA Red-Base when they arrive next week.

The Sylvania's were about $110.00 for the pair. The RCA's were $150.00 for the pair. Expensive, yes, but with a 10,000 hour lifespan they're worth it in my opinion.

The Cayin A-88T is WAY sensitive to power cords...if you buy one experiment and find what works best in your rig.

Also remember this amp is NOT self-biasing, regardless of the false info in some publications. Biasing it is easy, but you must remove the bottom cover and stand the amp on it's side to do so. Pain in the ass? Yep, but the amp is worth the trouble.