Stock Tubes on Cayin TA-30?

What kind of EL34 tubes are stock on the Cayin TA-30? I bought an extra set of Svetlana "Winged C" EL34's, and honestly i like the stock tubes better. the Svet's seems a little too bright and the imaging seemed better to me on the stock tubes.
I dunno-Some Chinese tube I guess... Paul @ 2B said it's tough to improve on the stock tubes. I think he mentioned an Electro Harmonix el34 that worked well in the output stage. The stock 12au7 were good - and the JJ tesla ecc83 for the 12ax7.

Ive really been enjoying the amp as is and am leery of touching it ;-) I restore and mess with old motorcycles, and the worst damage I've seen has been done needlessly on 'upgrades' or 'fixing it'. If it ain't broke...
You didn't state how much time you had on your Svetlana's EL-34 tubes. They do have a bright edge when new. They need 40-50 hours to smooooooth out. I have the Svetlana EL-34's in my TA-30 and they do a great job. This is the fun part of tube rolling. You pick your flavor. You may have a better match with your system with one tube or another. Just give them time to break in first. Enjoy this great amp.
yeah i'll have to break them in a bit. I did find out the stock tubes are Valve Art's EL34

it's just you get different answers for tube break in period. some say after a couple hours, some say 30-50 hours.... i'll just put them in and hit repeat for a while and evaluate them later. see what happens.

and i am definitely enjoying this amp. it will be my last for a long time. to only other piece left for me is a great redbook CD player for less than $500
Has anyone rolled the Electro-Harmonix 6CA7/EL34 Big Bottles?

i'd like to know that as well..... if someone can comment on the sound from the tubes you mentioned....
I too replaced the stock tubes with Svetlana EL-34 Winged C's and the sound has much improved. Compared I found the stock tubes much too bright.
I'm thinking of buying a used, unmodified TA-30,
is it awkward to bias them?

I've used a stock TA-30 for the past year or so; biasing is a slight pain, but not enough so that it's not worth it to get the amp. The amp has to be turned upside-down & the bottom removed--it's held on by 8 (I think) machine screws. The actual biasing process used to be described on the Bizzy Bee website. Dunno if it's still there though.

As I said, a minor pain, but it doesn't have to be done *that* often. I bought my TA-30 used on the 'gon, & it had the stock tubes. I don't know how old they were, but I was biasing about once a month with significant (25-35 mV) drops in bias each time. Replaced them with a set of new Electro-harmonix EL-34s after a few months, after which I dropped the biasing to about once a quarter, with a change in current of only a few mV (if that) each time. Moral: old tubes apparently don't hold a bias setting well, but with new ones, the procedure doesn't have to performed too often. Moral II: don't let fear of biasing keep you from getting this amp--it's an excellent value, and the most important change I've made to my system (excluding the decision to 'try' vinyl a couple years ago).

Just for completeness (and return to topic), the sound of the Electroharmonix tubes: definitely leaner than the stock tubes, which were a little juicy and soft to my ears in my system. Take that with a grain of salt, though, because my stock tubes were apparently pretty run down when I got them. The EH's could possibly do with a bit more body, although they still beat the pants off my previous NAD C370 in this regard. The EH's also initially had a slightly whitish sound up top, but this has gone away. My speakers are a bit lean-sounding themselves, though, so I suspect the EH tubes are themselves pretty neutral. Others with more tube-rolling experience can probably say more.