just as a note, I have heard MOST but not all of these tubes in various ST70s I've had over the years, I'll agree with Bob the Shugang's are excellent, I have saved a quad of them with original Shugang logo from about 4 years ago, along with a quad of 60s era GE 6CA7 "fat boys"
(my favorites) and the newer EH6CA7 "fat boy" tubes. The standard production JJ EL34 is an excellent low cost tube.
I used to have a NOS quad of Siemens EL34s from the 70s and they were also excellent.
Roy www.tubes4hifi.com

I have to agree on the Shuguang EL34s. They sound good in my Dynaco Mk II amplifiers, though the "matched pair" I tried weren't matched as well as I'd like, if my Dynaco were still stock and running a single bias adjustment pot.

With separate bias adjustments, the degree of mismatch I found is no problem; and the match would probably be much better had the tubes been purchased from a vendor as a matched pair or matched quad. These were from a local guitar amp repair shop, which had bought them in bulk straight from China via an EBay listing; so there was no matching done.

What do you guys think about the Mesa Boogie EL34 matched pairs (part No. STR 447)? Several sources say, they are Sovtek Russian tubes.

What about the Russian tubes? What's the number 6P3N or something?

Anyway, I like this thread, as when I get to rebuild the ST70 and enter the Dynaco world, I want some "cheaper" (read lost cost) tubes to fire it up on, rather than toast some rare tube!!!

I say "cheaper" because I don't want to buy junk, as I will keep them as spares.

Jason

The russian is 6P3S-E, and it is a very fine tube in the S-70. Still cheap and not junk. IMHO it is much better than modern EL34.

6P3S-e tubes reproduce mid to high range frequencies wonderfully in an ST70. Highly recommended tubes, but a bit light bass wise. I bought a tightly matched quad for $27 recently...Doesn't get cheaper than that for NOS power tubes....

Kevco,

where did you get a matched quad for that?

j4570 wrote:Kevco,

where did you get a matched quad for that?

Sorry, I haven't been through here in a while...Ebay seller BSA_79 is my guy. He is in Ural, Russian Federation. He doesn't sell these as "matched" but my quad was very evenly matched, probably because they are military tubes made on the same tooling, probably on the same day. Took 21 days to ship to me in Pennsylvania, USA.
http://myworld.ebay.com/bsa_79/

kevco wrote:

j4570 wrote:Kevco,

where did you get a matched quad for that?

Ebay seller BSA_79 is my guy. He is in Ural, Russian Federation.

Same source for me. Package arrived in about 2 weeks in nice shape with my name and address in English and Russian. Great sounding tubes that keep getting better.

Whoa...How do they sound up against KT77's?...$35 for a quad of Russian Submarine Tubes is worth the price just to say that you have "Red October" Tubes..

I haven't had anything other than EL34's, so I cant comment on a KT77 comparison.

[/quote]Same source for me. Package arrived in about 2 weeks in nice shape with my name and address in English and Russian. Great sounding tubes that keep getting better. [/quote]

Yeah! I really liked seeing my name in Cyrillic so much I removed the shipping label and saved it...KT77's are overpriced unless you're talking JJ's and I just don't like their tubes at all. Between the masses of EL-34 options out there and the cool beam tube choices (KT-66, 6CA7EH, 6P3S-E, etc.) I honestly see no need for KT77's...

kevco wrote:6P3S-e tubes reproduce mid to high range frequencies wonderfully in an ST70. Highly recommended tubes, but a bit light bass wise. I bought a tightly matched quad for $27 recently...Doesn't get cheaper than that for NOS power tubes....

Interesting thread, I have an st70 and two Mark4 that have had their quad capacitors, bias circuits and capacitors upgraded. I was lucky in that all came with Mullard el34 xf2 and all test good. But I am intrigued with trying the 6p3s-e tubes mainly because of price and the fun of rolling, are these tubes plug and play on an almost stock units are there other tubes in addition to these that are? I currently bias @1.46 do I need to change that.I use these in a bi-amp set up with these rotating as my hi-end with ss on the low end.
Gary

I just checked out BSA_79 on ebay and he says the 6P3S-e's are rated at 5000 hrs. I was wondering how the Shuguangs might compare. I can get them down the street for $12 ea., but would love to try the 6P3S-e's.