Running 6L6's with the bias switch set on EL34's. Dual recto

[tele_jas]

Allright, my other guitarist called me this morning and said he has a chance to score a dual rectifier pretty cheap....but when he tried it out and looked it over he noticed that the amp had 6L6's in it but the bias switch was set to EL34 and he thinking its been that way for a while! So, is that a bad thing or will he just need to replace the tubes? Will there be any other issues that might pop up later?

 

[RoadKinger483]

I've read Bob at Eurotubes does something like this because suppoedly the fixed 6L6 bias setting is set too cold so he switches it to EL34 to get the bias warmer and get a warmer tone. But, I don't know about doing it with 6L6's??? I think, he does it with some different modle of tubes. If i'm not mistake i think its KT88's of 6V6's...... :?

 

[RoadKinger483]

Sorry, KT88's OR 6V6's. I'm not use to typing this early in the morning!!!

 

[oyster]

The following tubes will work in EL34 setting & I have used them all...but they were hand selected for that purpose by Eurotubes. Both Mesa and Eurotubes told me as far as 6L6 goes you can't / shouldn't just stick in normal 6L6s they have to be hand selected for the purpose of running them in EL34 setting. They suggested that normal 6L6s would probably work for a short time (anywhere from 2 minutes to several weeks or even months, very unpredictable) then go up in smoke and could damage the amp.

KT88
E34L
el34 (of course)
6V6
6L6

 

[Guitarzan]

The following tubes will work in EL34 setting & I have used them all...but they were hand selected for that purpose by Eurotubes. Both Mesa and Eurotubes told me as far as 6L6 goes you can't / shouldn't just stick in normal 6L6s they have to be hand selected for the purpose of running them in EL34 setting. They suggested that normal 6L6s would probably work for a short time (anywhere from 2 minutes to several weeks or even months, very unpredictable) then go up in smoke and could damage the amp.

KT88
E34L
el34 (of course)
6V6
6L6

In the El-34 setting... Which did you like best?

 

[Boogiebabies]

I bought a set of # 26 JJ 6L6's from Bob. In the EL-34 bias position they draw about -35ma, which is pretty good sounding and warm. In the 6L6 bias position they draw 17ma and sound like Henry Winkler covered in Bee's.

 

[Guitarzan]

sound like Henry Winkler covered in Bee's.

Correctamundo!

 

[Russ]

http://www.youtube.com/watch?v=eLdjwGV5730

:lol: Sorry, I couldn't resist... :lol:

 

[JamesD]

lol good movie

 

[Boogiebabies]

I'm Mr. Beefy !!!

 

[Monsta-Tone]

Tele,

I just looked at my drawings for the 2 channel DR, and the EL-34 setting will actually lower the Bias setting from -51v (6L6's) to -39v (EL-34's).


If the amp still works, he should be fine, but a new set of Power Tubes & Phase Inverter Tube would be in order.


Look at the Output Transformer and see if there is any "Goop," for lack of a better word, that may have leaked out of the transformer. If it has gotten significantly warm, the resins inside the transformer will have heated up and leaked out the sides.


On the bright side, if the price is right and the transformer fails later, he may still get it cheap enough that it is very worth it.



Maybe have your friend take a new set (or better yet, a set of known good tubes) of tubes with him when he goes to get it and try it out again. See if it makes any unwanted noises or has no power.


Hope this helps, could be B.S. You never know.

 

[oyster]

The following tubes will work in EL34 setting & I have used them all...but they were hand selected for that purpose by Eurotubes. Both Mesa and Eurotubes told me as far as 6L6 goes you can't / shouldn't just stick in normal 6L6s they have to be hand selected for the purpose of running them in EL34 setting. They suggested that normal 6L6s would probably work for a short time (anywhere from 2 minutes to several weeks or even months, very unpredictable) then go up in smoke and could damage the amp.

KT88
E34L
el34 (of course)
6V6
6L6

In the El-34 setting... Which did you like best?

I am currently running 6L6 (inside pair) and 6V6 (outside pair). I also like regular EL34s combined with either 6L6 or 6V6 a lot. didn't like the KT88s or E34Ls. You just gotta try em out and see what you like best.