Opinions of Sovtek tubes

[knotscott]

Hi gang! First timer here, and relatively new amp builder...got one single ended Les Paul Jr type guitar amp under my belt about a month ago.

Anyway, I want to build a 2nd amp now, and am leaning towards a 10-15 watt push/pull type. I realize this is a broad question with several possible views, but I've managed to obtain a couple of Sovtek EL-84's and 12AX7s at reasonable price and am curious to hear opinions of their general quality compared to other brands, NOS, new Chineses tubes, etc. I'm assuming there's a reason that they're cheaper than some others. Yeh or Neh?

Also, I'd like to hear opinions of how the EL-84s compare to a typical 6V6G in push/pull guitar amp.

TIA for your input!

For those curious, here's a couple of pics of the 1st amp.

[tubeswell]

I like the Sovtek EL84 s for their brightness, and cheapness. EL84s generally tend to be rattlier and don't last as long as other types of output tubes, but they have 'swoitin chywm'.

I haven't tried EL84Ms yet but they are reportedly more robust, can handle higher plate voltages, and are less-bright than the standard EL84s. I might splash out for a set for my next replacements, but you can't go past the Sovtek EL84s for price. I think with a pair of EL84s in a push-pull configuration, you could get about 25W; - 50W with a quad.

[generic_user]

you may not see this post but personally i dont really care how long the tube would lasts my concern would be how it sounds. generally speaking ive seen sovteks were pretty cheap but they have always sounded really good. in my opinion all the tubes sovtek makes sound great when the bias is right.

[tubeswell]

Like I said, I like them too (because of their sound). I have a C30 with 4 x Sovtek EL84s fitted. Having said that I bought a couple lately which red-plated within two minutes of putting them in my amp. The guy who sold them to me tried to tell me my amp was at fault Said I had the bias adjusted wrong but teh idiot didn't realise that my amp is one where there is no bias adjustment. You just plug in the replacements and play. To drive it home, the old ones worked fine when I put them back in and what's more I got some more new ones from another supplier and they work fine. I think there may be the odd bad batch or two.

BTW - I would be very wary of buying valves from Logic Research Electronics in Stratford, NZ. They don't appear to stand by their merchandise - they haven't replaced the duds they sold me a couple of months ago yet. (But here's hoping they might yet restore my faith in them)

[Angelo Skouras]

What a wonderful wood box!

Congratulations for the work/idea/choice!

Did you build it on your own? How? I’ve made a lot of amps, all sounding great, but never had such a good artwork for chassis!

I think that brand and price of a tube does not affect the “quality” of its sound. They are better or worse in terms of noise, or electric stamina, but witch one “sounds” better is clearly a matter of personal taste.

I thing that NOS tubes are more expensive because they are more rare… I thing that NOS are for collectors-not for engineer and sound lovers…

Anyway, I want info about how did you made/obtained this box. If you don’t want to use this thread to explain me, use o_glykolemis@yahoo.gr (my mail)

Thank you in advance!

[tubeswell]

Well blow me down! I got an email from Logic Research Electronics today saying they are sending replacements - so I take back everything dark I said of course and now I thoroughly endorse this company and will buy more stuff of them in the future etc.

[Baxthorpe]

You could try building a Marshall 18W - 3 x 12AX7 and 2 x EL84, and there's a 36W version using 2 x 6V6.

Old Russian 6P14P (Cyrillic: 6П14П) EL84 are very reliable, but a little dark sounding. The old 6P14P-EV (Cyrillic: 6П14П-ЕВ) military versions draw a little more heater current than standard Western versions, but feed 'em well and they sound OK. The 6P14P-E (Cyrillic: 6П14П-Е) is the best of the old types to get, that is your EL84M type.

The new Sovtek EL84 are based on the same old 6P14P design, but updated for a brighter sound. I like the old ones better; they last well and they are heavy built, glass is close to bullet proof.

[clyde1]

I believe that the "EB" or "EV" designation denotes the EL84M.

[Baxthorpe]

Russian valves suffix E denotes a low noise and long life type.
There are two types similar to the EL84M - 6p14p-e and 6p14p-er.

While the 6p14p-ev meets the noise and lifetime specs, B (v) indicates "intended for military use". A lot of Russian military types have increased heater current consumption, typically 20% over the standard type valve, so you need to be aware exactly what you are buying.

[Chuck_Farlee]

Explanation of Russian tube designation system:

http://www.klausmobile.narod.ru/td/gost_e.htm

[Baxthorpe]

That's handy! Unfortunately it does not explain what the r (P) means - and I never found that out!

Note the bit where it says specifications varied from factory to factory - there are some Russian 6L6GC out there, and some 6L6GT from other places. You really do have to be careful ...

I might mention that the cyrillic letter which looks like two "K" stuck together with one the wrong way round, and is given in that reference as corresponding to "J", is often given as "zh" in dealers' lists.

[Chuck_Farlee]

Note the bit where it says specifications varied from factory to factory - there are some Russian 6L6GC out there, and some 6L6GT from other places. You really do have to be careful ...


AFAIK, there never was a "6L6GT" produced by Western tube manufacturers. The GT designator is for the small 6v6-sized envelope. I believe the tubes marked "6L6GT" are the regular 6P3S without the EV suffixes. Groove tubes passed these off as their 6V6HD back in the mid 90s when the only 6V6 being produced was the Russian 6P6S. Unfortunately, the 6P3S is still similar to a 6L6 in ratings with the same filament current draw.

[Baxthorpe]

You may be right to say the 6L6GT was never made by Western manufacturers. The only examples I have ever seen in Western livery are re-labelled Russian production - I still have a couple of Brimar 6L6GT marked Made In USSR.

Whatever, the original statement was badly phrased.

The point is that, for a given Russian type number, there can be deviations from the specification in the products of some factories.
Generally, the products will always meet the basic Russian specification, but some may be better than the specification in some respects.
Sometimes, the product may meet a western specification, although the Russian specification is nominally lower than the western spec. - so even when the number is the same, you may need to know who made the tubes, if you want to be assured they correspond to a western specification.

The illustration with the 6L6 types -

You have to remember that the E suffix is supposed to designate a long life tube, although it usually also indicates a low noise type.
Yes, those 6L6GT are regular 6p3s, but they might also be 6p3s-e from some factories - a long life low power type.
Some 6p3s-e are equivalent to 6L6GC, but not all. From memory, Svetlana made equivalents, and there was at least one other that made true equivalent 6L6GC.
You have to rely on your supplier's knowledge that he is supplying a true equivalent.

Fortunately, most useful Russian types are more consistent than the 6p3s and its varietals - it is probably the "worst case" for variation.

[Chuck_Farlee]

In my experience the 6P3S-E and 6PS-EV are exactly the same as the Sovtek 5881 (which isn't a real 5881, BTW). The 6P3S tubes have a full-size base and a skinny envelope, almost like a short EL34.

It seems to me that the Svetlana tubes were real 6L6GCs, made to the western specs. The 6P3S-E and 6P3S-EV were made to be used in Russian Mig fighters and not really in the 6L6 family. They just happen to be close enough to use in 6L6 circuits.

[MWJB]

5881 always was a military designation, they were not conceived for musical instrument amps (not that i'm suggesting that the Russian tube & New Jersey Tung Sol have anything in common other than designation).

[Old Tele man]

...the 5XXX-series designation was used to distinguish MIL-SPEC tubes from the commerical and industrial tubes of the day, with many tubes simply being "on-spec" versions of their commercial / industrial counterparts, ie: 5881 = 6L6WGB and 5751 = 12AX7WA, etc.

...the real difference was that the 5XXX tubes were "tested & guaranteed" to meet specs while their commercial / industrial counterparts weren't.

[hasserl]

IMO the Sovtek EL84's sound like crap and I wouldn't advise anyone to use them. They sound horrid, just horrid. Stiff, wooden, brittle, they don't sound good when clean or when driven to distort.

Here's a write up I did a while ago on EL84 tubes: http://members.dslextreme.com/users/rlhasse/Ampdocs/EL84Comparison.pdf Note the losers in this comparo.

I've been using the same set of 6N14N-EP tubes in my main practice and giging amp since this time and they still sound great. These tubes are priced very well, very competitive to anything else out there, including the Sovteks.

[Baxthorpe]

US tubes with numbers only are industrial type, and Special Quality - but they are not military unless they are JAN, CV, or CK marked, even if they meet the military speciication.

I agree with Hasserl that the NOS Russki tubes are better value than about anything on the market, but I suspect that some of the crunch in his tests was coming from the preamp, and the tubes he rated better were the ones that "forgave" that crunch, rather than passing it on.
It would be interesting to repeat that test, but with the pre-amp deliberately "dumbed down", perhaps with a 5751 or 12AZ7 as PI instead of a 12AX7.
Or maybe I'm just talking through the wrong orifice as usual ....

[Chuck_Farlee]

and 5751 = 12AX7WA

The 5751 is the 9-pin equivalent of the 6SL7 just as the 6CG7/6FQ7 is equivalent to the 6SN7.

[Chuck_Farlee]

I've been using the same set of 6N14N-EP tubes in my main practice and giging amp since this time and they still sound great. These tubes are priced very well, very competitive to anything else out there, including the Sovteks.

AFAIK, the Sovtek EL84M is same as the 6P14P-EV. Maybe yours are from a different factory?

[hasserl]

I agree with Hasserl that the NOS Russki tubes are better value than about anything on the market, but I suspect that some of the crunch in his tests was coming from the preamp, and the tubes he rated better were the ones that "forgave" that crunch, rather than passing it on.
It would be interesting to repeat that test, but with the pre-amp deliberately "dumbed down", perhaps with a 5751 or 12AZ7 as PI instead of a 12AX7.
Or maybe I'm just talking through the wrong orifice as usual ....

I'm sure that part of the crunch was coming from the PI, as in every amp I know of other than the 18 watt Marshall style amp with the single gain stage before the PI, the PI distorts before the power tubes do. But that's not part of the preamp. But yeah, I'm sure the PI was clipping anyway before the power tubes were. It's just the nature of the beast. The amp I used is a channel switcher with a very nice clean channel, as nice as any amp. That channel only has two gain stages, with a Bax style tone stack between them. It has a lot of headroom, and when it breaks up it breaks up first at the PI, then the power tubes. Any breakup at the preamp is minimal and comes in last. I used that channel to push the power tubes hard. Though I also used the "dirty" channel to hit the tubes with even higher voltage levels.

But, the biggest problem I had with the tubes that faired poorly in my comparison was they didn't sound good clean or dirty. The tubes that sounded good sounded good in either case. The Sovteks or the Telefunkens or Amperex tubes may have sounded okay when heard in isolation. But when compared to the others their shortcomings were readily apparent.

[Manic]

But, the biggest problem I had with the tubes that faired poorly in my comparison was they didn't sound good clean or dirty. The tubes that sounded good sounded good in either case.

Yup, thats been My finding too. Which would also include preamp tubes.