Retubing an ST-70 - what are your favorite EL34s?

[LowRedMoon]

I was going to do a simple Electro Harmonix drop, but thought I'd ask you folks which EL34s you tend to prefer for this amp. The ones that are in the amp already are mismatched - I don't know what brands are in it, as I have not yet received the amp in the mail.

I listen to nearly the full spectrum of musical types and genres, but will be spending the majority of my listening time with rockin' rockers, female vocalists and rockin' female vocalists.

Thanks for the input.

Adam

[TomMcNally]

I went with the larger bottle Valve Arts in my Dynaco ST-70 last time - I haven't listened to it enough to blow them out. I'd stay away from the low end tubes - they seem to self destruct. I have an "octet" (2 sets of matched quads) in my Velleman K-4000 which is connected to a huge pair of Cerwin Vega! speakers that shake the house, no fireworks in them yet either, after about 7 years.

[MarkC]

LowRed,

I use a quad matched pair of Svets I got from triode years ago in mine and have been really happy with them....I don't have experience with any other brands other than mix n match so, I can't give you a good comparison. The blue JJs are pretty cool looking. Might add some to the rock scene... Yellow_Light_Colorz_PDT_11

Mark

[EWBrown]

I've used both J/J EL34s and Svetlanas, both sound very good, to the point that I consider them near identical. I have a NOS quad of GE 6CA7s that I have been saving for that "special ocasion", I found them many years ago at a hamfest in Vermont for dirt cheap.

Sovteks / EHs are also very good fo the cost,

/ed B in NH

[TomMcNally]

whoops - in my post above I didn't mention that the big Velleman has Svetlanas in it, not Valve Arts as it would appear.

[EWBrown]

I'd stay away from the Valve Art and most ofher Chinese EL34s, as well as 5AR4s, as these just aren't quite up to snuff for this kind of tubes. The VA and "Sino (Made in Chian) 5AR4s are real firecrackers when ysed much beyond 5Y3 ratings...
THe Chinese made power triodes and 807s are pretty good, just their power pentodes and BPTs are somewhat "lacking".

[Thermion]

I really like the JJ tubes. I am using a quad of JJ EL34s in my ST70, and love the sound. I have also tried the EI tubes and Russian tubes with good results. I really think the JJ's are the best current production power tubes. I have also used their EL84s and KT-88s. The only problem is that they bias real hot. I wouldn't use them in an auto bias arrangement with a vintage amp, but the results would be spectacular. When using them in a fixed bias circuit, I always crank the pots back before switching to JJ's.

JT

[TomMcNally]

Anyone have any experience with the Sovtek 5AR4 ? I bought one for the ST-70/7591 clone, but wound up using the original Heathkit/Mullard in that. I think I'll use the Sovtek 5AR4 in an 832 amp I'm going to build.



Isn't JJ the sucessor to Tesla ? Those EL-34's were firecrackers for sure. I have 2 quads of the EL-84's - 4 in the Baby Blue and 4 in the amp everyone loves to hate - the Dynaco SCA-35. They both sound good, but yeah - they do generate up some heat.

[Thermion]

Anyone have any experience with the Sovtek 5AR4 ?

I bought a pair of Sovtek 5AR4's from the Audio Advisor back in the early 90's. I'm still using these in my Dyna MKIIIs through several power tube changes. I would guess they have 15,000+ hours on them over 12+ years and still going strong.

Isn't JJ the sucessor to Tesla ? Those EL-34's were firecrackers for sure.

The JJ factory is the same one the Tesla tubes were made in. There has been some modernization and improved QA/QC since then. I have a quad of Teslovak Kt-88s that are nearly identical to the current JJ. The performance of both of these is just outstanding. I never heard anything but good reviews of the Tesla EL34 or E34L tubes.

JT

[Shannon Parks]

I also have a pair of Sovtek 5AR4 that get swapped around and have many hours and abuse on them. In particular, the one on my ST70 gets the abuse of getting constantly cycled on-off-on during testing on the bench. I trust them 100%.

Shannon

[LowRedMoon]

I see that the JJs are well loved. Thanks for all of the recommendations and bias warnings.

I forget what his name was, but a fellow at tubedepot recommended SVEL34 Cryovalves. At $70/pair, they're kinda pricey. Do any of you have any experience with these tubes? Personally, I get a little queazy when I see a tube with a hi-tech sounding name.

Also, have any of you ever tried the EH 6CA7s?