diytube.com

I just got a st-70 and plan to upgrade to the VTA board, change the cap, and replace the OP tubes. I have the original Mullard/Dynaco in the amp at this time and they sound great. Will the Sovtek's come close to the Mullards? Also what is the life expectancy on OP tubes

Welcome to DIYtube!

I have some Sovtek EL34G. While there are some Sovteks I like, these are garbage. I know the EL34WXT came later... hopefully they improved them. Even still, I wouldn't spend the money on Sovtek EL34. Get some Svetlana instead, they're a known good quantity. I've also heard good things about the reisssue/new production tubes. There's a "Mullard" and a "Tung-Sol". Both are made in Russia under the direction of New Sensor, but they're supposedly pretty good.

= junk

I like the new production "Tung-Sol" KT-66 tubes for the ST-70. However, the bias supply will probably need to be modified to run them.

The JJ EL-34L tubes I did not like. They failed after about a year.

The Sovtek EL34WXT tubes are the least expensive EL34 tubes I have ever seen.

http://www.tubedepot.com/el346ca7.html

and

http://www.tubedepot.com/so-el34wxt.html

"While not as harmonically rich as the SED SVEL34 - the Sovtek EL34WXT is a great tube for darker sounding amplifiers. It features a unique grid block construction which allows it to operate at higher trans-conductance and power ratings than most other EL34. In comparison tests with other brands - the Sovtek EL34WXT was found to have as much as 6% higher output at the same non-linear distortion level."

The EL34WXT tubes do not seem (to me at least) a suitable tube for HI-FI amps. Guitar amps, perhaps.

IMO, Winged =C= EL34 beat the Mullards hands down.

Do use a Sovtek GZ34 for the rectifier though. I have a dustbin of brand new JJ and Shuguang as well as NOS GE and Sylvania 5AR4's from the punishment they go through.

Cheers!

What about Electro -Harmonix el34 EH ?? The price seems good has any one here used them?

Allso will the 6ca7 work better than the el34's I know I'm asking alot of questions, I just trying to learn here Thanks guy's

Tanner wrote:What about Electro -Harmonix el34 EH ?? The price seems good has any one here used them?

Allso will the 6ca7 work better than the el34's I know I'm asking alot of questions, I just trying to learn here Thanks guy's

The Electro Harmonix EH tubes are affordable, and they will perform adequately in a HI-Fi amp, but they would not be my first choice.

6ca7 tubes are for the most part equivalent to EL-34s. The new production 6ca7 tubes I have never heard. But, for the manufactures who produce both tubes, their 6ca7s are more expensive than their EL-34s.

Thanks for the reply

I agree with Geek - I have some Winged C EL34's that I have been abusing in my eiclones for a few years now with no problems. They seem to be great tubes.

Regards,

I tried lots of new production tubes and am nearly completely away from those.

JJ? I had lots of sudden deaths. EH, I needed 8 (matched, haha) to get a good working set, usually taken to test new gear because it's not too bad when they die. Sovtek? Ugly. EH 6CA7 i bought 9 to get a set of six that work very fine and having two as backup.

When I think what I spend on experiments and the bunch of tubes not worth to keeb...

NOS is my favourite, Old stock used tubes my second best.

I got 4 Quintets of East german RFT made EL34 which are exceptional reliable and sounding very good.

I have a Quad of Ei 6CA7 fatbottles, I heard lots of bad stories about, but my set is reliable and working phantastic.

I have a Sextett NOS PhilipsECG/Sylvania 6CA7 which are phantastic and reliable.

I have a Quad used Sylvania which are as new and same as above.

I have a Quad used old stock Tesla, good sounding nice used tubes
I have a Quad Fender brand Tesla tubes as the above.

I have a sextet philips brownbase Double d-getter in excellent condition which should be my favourites of all time, but they are such expensive meanwhile, I rarely use them :) they are better than any other tube I own.

I would go for old stock or NOS.