Rectifier: running 6L6 with EL34 BIAS setting

[blackcom]

I've heard about a few players running their Rectifiers with 6L6 in EL34 BIAS setting cause they prefered the sound of this. Suposedly the tubes will run "hotter" or something like that. I'd really like to try this myself, but i'd like to know if it could damage the amp in anyway first.

Anyone with any experience on this matter?

 

[RR]

Personally, I don't think this is the wisest thing to do. May blow a grid resistor, tube(s) failure, sudden fuse blowing, ...

but be my guest?

I'm sure someone will come up with a rebuttal that its o-kay since I'm no electronic technician whizz.

Guitarzan? Boogiebabies? Stoke?

 

[parsky1]

Yea the tubes will run a little hotter... basically your're going to wear your tubes out a lot faster.

 

[Platypus]

I've heard of people doing this with tubes that were of a cooler grade than usual to get them hot enough for the effect without burning them out. I'm by no means an expert, hopefully some of our resident tube gurus can help you out.

 

[blackcom]

Well, I have enough tubes to go, just gotta make shure I don't melt my rectifier or anything...

 

[blackcom]

Called Mesa, they said it would be safe, but tubes would only have a 25% lifespan....

 

[oyster]

Really, this would actually work & not damage the amp other than tube life?? This is the first I heard of it.
Mesa actually told you it would be allright to do this? If so I'm rushing home to try it :wink:

 

[4nkam]

If you do a search on here, you'll find a thread where this was discussed including measurements/ratings for 6L6 v EL34 in bold/diode and tube/spongy. I tried it for awhile and it was ok, but I put it back to matching the tubes in use.

mJ

 

[Chad]

In 6L6 mode, the hottest bias is obtained by going with Bold/SS rectifier.

If you want to run a little hotter bias, try running EL34 mode with Spongy/Tube Rectifier. That should be the coldest EL34 bias, but it will still be hotter than 6L6/Bold/SS.

 

[LSS718]

First I want to say I have been reading the forum for a long time. I really enjoy people taking the time to share their knowledge and experiences with each other. I know we all are searching for that ultimate tone we hear in our head.

Over the last several years I have owned a Nomad 55 (twice), LSS, Lone Star, F-50, in addtion to some other makes like a Marshall 2061X. Recently I picked up a SROV head. I am older and not a heavy rock or metal player, but for what ever reason this amp seemed much more versatile then metal or modern rock. I play a lot of classic rock.

Since this post is discussing running 6L6's in the EL34 bias mode, I thought I give it a try at recording some comparison tracks. I am new to this home recording and these are the first tracks I have ever posted, so pointers would be appreciated. I did the same take using 4 different setting. Ch1 - Pushed to Max on gain, Ch2 - Raw @ 3:30 on Gain, Ch2 - Raw @ 3:30 on Gain in EL34 bias mode, and Ch2 - Vintage @ 12:30 on Gain. I was playing through the (MESA 5881 STR 425) 6L6's and my Marshall 2061CX with Celestion vintage reissue G12H30's. For guitar I was playing a PRS CU22 with JB in bridge position. Unfortuately I bumped the mic before the last take in the EL34 bias position, so the track is a little brighter than it would have been if the mic had not been bumped.

I don't know if the tubes would last long in the EL34 bias position, but it sure did enhance the gain, smooth it out, and warm up the sound. I sure did like it. If anyone tries it and has some feedback, I would appreciate it.

Since I have never posted personal clips to the internet before, I set up an account here. Hopefully the link works.

http://www.putfile.com/eddie53023

Also, one clip combines the pushed and EL34 bias take in a left and right pan. These 2 sounded best to me for the style music my clip represents.

 

[codyrg]

Called Mesa, they said it would be safe, but tubes would only have a 25% lifespan....

I just wanted to say that I too called Mesa about five minutes ago, they told me that it will run the tubes hotter but it will put stress on transister and that he wouldn't recomend doing it.

 

[Platypus]

Called Mesa, they said it would be safe, but tubes would only have a 25% lifespan....

I just wanted to say that I too called Mesa about five minutes ago, they told me that it will run the tubes hotter but it will put stress on transister and that he wouldn't recomend doing it.

Transformer maybe?

 

[codyrg]

Yup, transformer. I have the memory span of a small rodent and I know he said Trans.....so I decided to make up the rest

Either way, I know I won't be running my 6L6's in EL-34.

 

[Scary Guy IRL]

I know he said Trans.....so I decided to make up the rest

Put Stress on the Transexual...? the Transvestite..? :shock:

 

[jamme61]

Buy a weber bias rite and you can make sure your ok. It plugs into the power tube socket, and then the power tube plugs into it, you take your reading and your safe. On my LS I had to run the el34's on the 6l6's setting to get the tubes even close to where they should be. If any power tubes are running to cold, they sound thin and even can distort (cross over distortion, sounds real bad) here's a link to the bias rite for info
https://taweber.powweb.com/biasrite/br_page.htm
here's a link to the bias calculator page
http://www.webervst.com/tubes/calcbias.htm
hope this helps