Tube Recommendation for a '92 Dual Rec

[nephilim616]

What seems to be the most acceptable answer for the tube set on first year (Rev F specifically) Dual Recs? I've owned my Dual 'Racto' for about a year now and I've been wanting to replace the 5881s and preamp tubes that have been in it for 30+ years with some new ones.

All roads lead to various different brands/tube combo amalgamations (Genalex, JJ, Ruby, Mesa, etc.) so I'm having a hard time trying to find a decent combo that will sound crushing with my rig.

 

[Alpha Stryke]

I used / liked the Sovtek 6L6 - WXT+'s

 

[Beyond Black]

Winged C EL34’s sound KILLER in two channel Rectos.

 

[Nigel]

What seems to be the most acceptable answer for the tube set on first year (Rev F specifically) Dual Recs? I've owned my Dual 'Racto' for about a year now and I've been wanting to replace the 5881s and preamp tubes that have been in it for 30+ years with some new ones.

All roads lead to various different brands/tube combo amalgamations (Genalex, JJ, Ruby, Mesa, etc.) so I'm having a hard time trying to find a decent combo that will sound crushing with my rig.

What tones are your reference point, specifically, Albums/Songs/etc.?

 

[Alpha Stryke]

Winged C EL34’s sound KILLER in two channel Rectos.

Good luck finding a quad that aren't "factory seconds".

 

[Hiwatts-n-Gibsons]

Winged C EL34’s sound KILLER in two channel Rectos.

Came to say this. Also another way to make the amp more usable in tube rec mode (at least for me), was swapping in a pair of 5AR4/GZ34 rectifier tubes. It warms up the bias some, and decreases the rise time so the amp has significantly less sag in tube rec mode.

Fwiw if you really like the EL34's it's easy to mod the amp to run them safely with the silicone diodes. Contrary to Mesa's literature the problem with running EL34's in them has nothing to do with the quality of available EL34's, and everything to do with the underspec (for EL34) screen grid resistors. Swapping out the 2 watt SGR's for 5 watt versions will let you bias up a set of EL34's correctly without excess risk of frying the SGR's and taking out the tubes with them.

Edited to change increases to decreases.

 

[Alpha Stryke]

6L6's is the rectifier "sound" and EL-34's sound best w/ Marshalls but we all different.
My old 100 watt rectifier would shake "snow" off the ceiling tiles. Not kidding.

 

[anomaly]

I always have good luck with Mesa branded power tubes. They seem to sound the best in Mesa amps IMO, although it's very subtle.

 

[FourT6and2]

JJ 6L6GC
Sweet spot for bias in that amp is 55%.

 

[ChurchHill]

Also another way to make the amp more usable in tube rec mode (at least for me), was swapping in a pair of 5AR4/GZ34 rectifier tubes. It warms up the bias some, and decreases the rise time so the amp has significantly less sag in tube rec mode.

I'll second this. I've been using 5AR4s in my DR for a long time. The 5U4s it came with were just too saggy for me. Switching to the 5AR4s helped make the tube rectifier mode much more usable.

 

[311boogieman]

I have Mesa 6L6s now but generally have had great luck with JJ's too.

6L6's is the rectifier "sound" and EL-34's sound best w/ Marshalls but we all different.
My old 100 watt rectifier would shake "snow" off the ceiling tiles. Not kidding.

I think that was just dust CharvelDan

So what other Rectifier have you had in addition to the Single?

 

[Hiwatts-n-Gibsons]

6L6's is the rectifier "sound" and EL-34's sound best w/ Marshalls but we all different.
My old 100 watt rectifier would shake "snow" off the ceiling tiles. Not kidding.

I didn't really want the "sound" you are referencing, and imo EL34's sound best in Hiwatts. We like different sounds obviously.

 

[Hiwatts-n-Gibsons]

I have Mesa 6L6s now but generally have had great luck with JJ's too.



I think that was just dust CharvelDan

So what other Rectifier have you had in addition to the Single?

I can tell you my Tremoverb with EL34's would shake more than dust. Good vibrations were had.

Tbt my favorite powertubes with it were 6550's, but that was achieved using the loop to split the signal stereo sending one side to a 6550 head slaved as a power amp.

 

[FourT6and2]

I always have good luck with Mesa branded power tubes. They seem to sound the best in Mesa amps IMO, although it's very subtle.

Mesa-branded tubes are from all sorts of manufacturers. You can get Mesa-branded EL34 and 6L6 that are JJ, Sovtek, TAD, Shuguang, RFT, etc. So unless you know the specific STR code of the tube you're talking about, it's anybody's guess.

 

[FourT6and2]

I have Mesa 6L6s now but generally have had great luck with JJ's too.

The Mesa STR-445 is a JJ 6L6.

 

[Dale B]

I like the Sovtek or EH 6L6GC for the late 90's sound. If I want clear, I throw in Philips 7581A power tubes. JJ has always been all right. The older Ruby EL34B-STR was a good tube. I still have a stash of those. I have some of the RFT EL34s, but they don't really sound that great to me in those amps.

I absolutely loved the =C= EL34 or 6L6GC in those amps. It's just too bad those aren't being produced any longer. We lost one of the best modern power tubes when they stopped production. I wouldn't ever pay the astronomical prices being asked for them these days.

 

[311boogieman]

Mesa-branded tubes are from all sorts of manufacturers. You can get Mesa-branded EL34 and 6L6 that are JJ, Sovtek, TAD, Shuguang, RFT, etc. So unless you know the specific STR code of the tube you're talking about, it's anybody's guess.

For sure. I think when people say "Mesa Branded Tubes" they are only talking about the matching (color coding) that is done to try to give you a matched set that will work best within your given Rectifier. I've never bought tubes from Mesa so I wouldn't know directly, but I do know Mesa doesn't manufacture their own tubes.

 

[Nigel]

Bet JJ KT77’s would breathe fire at volume and Eurotubes can hook up the right current draw. Would give 6L6 bottom and top with mids better than the E34L too.

I agree with Bob Gjika that they are the best EL34 type available. They’re pentodes too, not true Kinkless Tetrodes.

But yeah if you want the real old school Recto sizzle and glass kick in the ass, 6L6’s are the way. JJ’s will sound more brown and smooth, for brootz Sylvania/Phillips is the way.

On the cheap, Russian 6P3S-E’s, aka the OG silver letter Sovtek 5881. Get the Foton ones if you can find ‘em.

 

[saxxamafone]

How do you deal with the ‘non mesa tubes’ and fixed bias thing with rectos?

 

[Nigel]

How do you deal with the ‘non mesa tubes’ and fixed bias thing with rectos?

Probes or guys like ET that grade their own and sell brand/model specific sets.