View Full Version : I liked Sovtek 5881s best !?
slegros
05-09-2009, 07:52 PM
I have a Bluesbreaker Reissue I decided to test power tubes in this weekend. The amp has:
Stock BBRI circuit
M25/H30 speakers
SS rectifier plug
JJ preamp tubes w/ Tung-Sol RI in V1
Tried 4 types of 6L6GC (JJ, Ruby, EH, GE), stock Sovtek 5881s, and Chinese kt66s. Still want to try EL34s. All were biased to 70%(of a 25w max-even for 6L6s- 41mA in this amp) after installing.
The 6L6s were close enough to each other to make a generalization. The 6L6s were just generally too fendery clean for me, and sounded 'hard' overdriven. The JJs especially were just too big in the bottom end for this amp(although they later worked awesome in a buddy's Ampeg 1x12!!).
Chinese KT66s drew a lot of current and I had to dial the bias pot almost to min to get 70% bias. I was really disappointed with these. I was expecting that Classic Marshall Kt66 sound, but it didnt happen. I dont know if I had a bad set of tubes, if the chinese repros are nothing like the originals, or if the differences between the original JTM circuit and the reissues are to blame here. I just hated them, they did have more mids, but were muddy clean and lacked punch overdriven.
No joke, maybe because the amp was designed for them? I liked the Sovtek 5881s best. I hadn't tried them since before the speaker and rectifier swap. Once back in it was right there-the Angus AC/DC sound... I can best describe these as not doing anything bad. Just the right amount of clean room, a bit grittier than the 6L6s, good clean sound, not as hard as the 6L6s overdriven, took pedals really well. No extreme EQ settings req'd to get a good sound. They didnt do anything specifically well-they just did NOTHING bad and were the best all-around compromise if that makes sense. This really surprised me!!
Anyone else find their amps work best with Sovtek 5881s?
RussB
05-09-2009, 09:02 PM
70% is too hot. try all the tubes at a lower setting and have another listen
slegros
05-09-2009, 09:25 PM
70% is too hot. try all the tubes at a lower setting and have another listen
I cant see that making much of a difference.
The KT66 I can't bias much lower with this set anyways, 70% was about 41mA, the lowest I could go with the KT66s was about 40mA with the trim pot bottomed out.
With the 6L6s and 5881s wouldn't going to 60% make them more glassy? If so definitely not what Im looking for. I want a very full warm sound, the 6L6s were quite hard when overdriven, wouldn't biasing at 60% make them even harder?
rockon1
05-09-2009, 10:00 PM
I cant see that making much of a difference.
With the 6L6s and 5881s wouldn't going to 60% make them more glassy? If so definitely not what Im looking for. I want a very full warm sound, the 6L6s were quite hard when overdriven, wouldn't biasing at 60% make them even harder?
Its always worth trying various bias settings.Sometimes too warm a setting makes things hard/harsh sounding. ....and OK I'll admit it I dont mind the way the Sovtek 5881WXT+'s sound in my Peavey Ultra either.Bob
strat a various
05-09-2009, 10:59 PM
I have em in my SF Twin, replaced RCA N.O.S. They don't sound as bad as everybody warned. I can live with them fine, and they're cheap. Also last longer than you read about.
But, they didn't work well in my MusicMan, so each amp is different.
slegros
05-09-2009, 11:35 PM
I have em in my SF Twin, replaced RCA N.O.S. They don't sound as bad as everybody warned. I can live with them fine, and they're cheap. Also last longer than you read about.
But, they didn't work well in my MusicMan, so each amp is different.
Agreed, while playing with the BBRI I was also playing with a friends Ampeg Superjet. The Sovteks were really bland in that, and the Ampeg just sounded awesome with the JJ 6L6s in it. The big bottom end of the JJs really gave the 1x12 a nice full sound.
aleclee
05-10-2009, 09:31 AM
I cant see that making much of a difference.
The KT66 I can't bias much lower with this set anyways, 70% was about 41mA, the lowest I could go with the KT66s was about 40mA with the trim pot bottomed out.
With the 6L6s and 5881s wouldn't going to 60% make them more glassy? If so definitely not what Im looking for. I want a very full warm sound, the 6L6s were quite hard when overdriven, wouldn't biasing at 60% make them even harder?You might be surprised. Hotter bias doesn't necessarily mean warmer tone. Set the bias to what sounds good and then check to make sure it's not frying your tubes. Your ears will thank you and in all likelihood you'll bias the tubes cooler, extending their life.
RussB
05-10-2009, 10:38 AM
You might be surprised. Hotter bias doesn't necessarily mean warmer tone. Set the bias to what sounds good and then check to make sure it's not frying your tubes. Your ears will thank you and in all likelihood you'll bias the tubes cooler, extending their life.
copy that :)
ScottB
05-10-2009, 11:18 AM
The Sovtek 5881's sound pretty good in my Zinky Superfly. It was designed around them, too.
slegros
05-10-2009, 12:44 PM
You might be surprised. Hotter bias doesn't necessarily mean warmer tone. Set the bias to what sounds good and then check to make sure it's not frying your tubes. Your ears will thank you and in all likelihood you'll bias the tubes cooler, extending their life.
Thanks for the info all!!! I retried the tubes(except for the KT66) at a variety of bias settings. The amp runs about 420V(i know-slight drift with bias adjust!). I ran a range from 35 to 50mA(50-70% using 30w for 6L6GC and 420V). As expected the sound got fuller but lost a bit of detail as bias increased. Ill say this-bias adjustment IS NOT a substitute for tube type. While some tubes responded better to different bias settings they still retained their individual characteristics.
I still liked the Sovteks best in this amp biased around 40mA..... Dissipating 16.8w, fairly conservative for a Sovtek 5881?
rockon1
05-10-2009, 05:23 PM
Well there you have it! The Sovteks are the subjective winner. 40 ma at 420 is a pretty conservative 55% idle dissapation. They should last longer. Bear in mind the Sovtek 5881 isnt a "real" 5881 as of old which is a 23 watt tube. Its a 30 watt tube more like a 6L6. Bob
Are we talking about the full-based 5881 Sovteks? Or the wafer based ones?
slegros
05-11-2009, 12:57 AM
Wafer based. Biased at 40mA they were well balanced, biased any hotter and they got a bit blurry. The 6L6s no matter where biased were just too glassy for me in this amp.
gldtp99
05-11-2009, 01:23 AM
Sovtek tubes sound good in some amps, it's no suprise to me--- i used to despise all Sovtek output tubes because of what i'd read on different forums---- then i started re-tubing some amps for folks with little $$$ with different Sovtek 5881's and 6L6WXT's---- and to my suprise.........sometimes in some amps they sounded really good----not always in all types of amps, but then no type of affordable tube covers all the bases in all types of amps.
Last nite several players were over demo'ing amps and played many different real Fenders and Marshalls as well as many amps that i'd built----one '65 Fender Bandmaster w/Heyboer Bassman OT (w/4/8/16 taps) i'd rebuilt that was one of their favorite clean heads has ALL new production tubes in it ----- Sovtek 6L6WXT+'s for outputs and a RI Tung-Sol in V1 and this amp does take to the new production tubes in a good way------ but if A/B'd with my #1 personal '65 Fender Bandmaster (with RCA Blackplate 6L6GC's and selected USA pre tubes) my personal amp has a much richer, more detailed harmonic content......... it just sounds better------- and no, i didn't let them play both amps back-to-back---- my personal amps are for me, not for demos.
But by itself and not directly compared to a really superior sounding, big $$$ tubed, same yr, same model amp (best BF Bandmaster tone i've ever played---and i've had/have quite a few of them)--- the '65 Bandmaster/Bassman OT head with the new production tubes does sound good----- the one guy "marveled" about how toneful it was and how little backround noise it has compared to some Hot Rod series Fender he just sold-----and then his eyes lit up when i had him use my Keeley Tubescreamer with the '65 BF Bandmaster/Bassman OT head thru a Marshall 1960B.
If it sounds good, then it is good---- Trust your Ears !!!...................gldtp99
rockon1
05-11-2009, 04:23 AM
Are we talking about the full-based 5881 Sovteks? Or the wafer based ones?
Is there really a difference?(aside from the base) Bob
Baxtercat
05-11-2009, 12:01 PM
....supposed to be the same thing, just more plastic on one so the Fender-style grippers can hold 'em.
I like 'em and run 'em in 2 or 3 of my amps. [They were designed to handle the stresses of USSR ICBMs, maybe? http://www.thegearpage.net/board/images/icons/icon7.gif ]
I've had a pair in my main amp for 14 years and I must gig with that thing at least once a week [with judicious use of the standby switch, of course!].
Is there really a difference?(aside from the base) Bob
Who knows?
The Sovtek 5881's sound pretty good in my Zinky Superfly. It was designed around them, too.
Ever try JJ 6L6's? I put some in my MOFO and liked them much better.
EDIT: Until tonight...5881's biased over 25w idle sound THE SAME as the JJ's, with tighter bass.
rockstarjay
05-12-2009, 05:08 AM
Is there really a difference?(aside from the base) Bob
No I've played lots of them and researched pretty extensively. They are different from the wxt+, though. They can handle 500 plate volts but have about 20% less output than an actual 6l6gc. If your interested check out Sovtek 5881 WXT/6L6 WGC Tube Guide (http://www.jayskyler.com/guitar-gear-guide/sovtek-5881-wxt-6l6-wgc-tube-guide.html) for what all the variants and Russian equivalents are.
rockstarjay
05-12-2009, 05:11 AM
They are good for high gain in big X-former amps generally.
No I've played lots of them and researched pretty extensively. They are different from the wxt+, though. They can handle 500 plate volts but have about 20% less output than an actual 6l6gc. If your interested check out Sovtek 5881 WXT/6L6 WGC Tube Guide (http://www.jayskyler.com/guitar-gear-guide/sovtek-5881-wxt-6l6-wgc-tube-guide.html) for what all the variants and Russian equivalents are.
They're not as loud as JJ 6L6C's, however, others have reported they will put out 40W without red plating. Have you seen this?
Observe: http://www.blueguitar.org/new/text/aga_posts/Mic_Kaczmarczik_tube_info.pdf
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