[ton1313]

Hi all,

New to tubes, and just got a used Cayin A50T EL-34 based amp. It arrived with and is currently running the JJ KT-77 on the output tubes, and 12AX7 & 12AU7 are from RCA.

I love the amp it sounds great with the Zu Essence, but now after reading all of the tube rolling stories, does anyone have suggestons for the tubes that work magic with this amp?

Should I be looking to roll tubes or should I invest in the Herbie's tube isolators?

Just curious , and appreciate the tips.

[bunnyma357]

I don't have a Cayin, but I've got a Yaqin that uses EL34's and a Onix/Melody that uses 12AX7's and 12AU7's. I've found that you get much more bang for the buck with swapping the preamp tubes rather than the power tubes. It sounds like you may already have pretty decent tubes in there. If you like what you have the Herbies stuff should improve sound, and can be used with new tubes if you do decide to roll tubes, so you might start there.

For the 12AU7 my favorite is an NOS RFT 12AU7 - reasonable price and sounds better than any of the 5814's I tried.

For 12AX7's I have some NOS Raytheons that I use in my phono stage and like.

For the integrated amp I used to prefer GE 5751 Triple Mica Black Plates, but they are pricey. They provide about 70% of the gain of a 12AX7 and are generally interchangable, but you should research if that is true for your Cayin. Currently my favorite in the 12AX7 slot is to use a NOS RFT 12AT7, it provides a little less gain than the 5751 but works great in my amp, again you should do some research to see if swapping a 12AT7 for a 12AX7 is OK with your amp.

http://www.boiaudioworks.com/12AU7_ECC82RFTNOS

http://www.boiaudioworks.com/12AT7RFTNOSTriodeMatched      (I got mine from eBay)

For EL34's the only thing I tried were Groove Tube EL34M's which are new production Mullard copies, they sound nice, but there wasn't that big an improvement over the Chinese tubes that came with the amp.

Jim C

[Occam]

I don't own the Cayin A50T either, but when I heard it at a NY Rave, I was tremendously impressed. My comments are based on my perceptions of tubes on my CAT SL-1 preamp. I agree with Jim's recommendation of the East German RFT 12au7s. Although I prefer current production for availability and cost, the RFTs seem readily available and reasonably priced. Compared to the Jan Raytheons and RCA blackplates, I much prefer the RFTs.
As to 12ax7s, I really like the current Roosh'n Tung-Sol remakes, IMO, preferable to the mushy, but sweet Mullards, as well as to most Telefunkens.
As to what will work best in your system, dunno. It depends much on the rest of your system and your personal, subjective preferences.

FWIW,
Paul

[50jess]

I have EH 6CA7 power tubes and Tungsram 12AX7s and RFT 12AU7 in my Cayin A-50T.  You already have good tubes.  Try some capacitor modifications.  I changed mine to Mundorfs.

[50jess]

If you would love to tube roll, you can consider the ff 12AX7s - Mullard, Telefunken, Sylavania long Black Plates and Psvane and the ff 12AU7s - Mullard, Psvane.