6l6 tubes:How many hours before changing? & Bias questions

[KLINKDETROIT]

How many hours are too many for 6L6 tubes by Ruby?
I have a 1999 Mesa dual rectifier that is possibly in need of a tube change. I already have the new Mesas. The Chinese Ruby tubes are in it now and have about 350 hours on them. not sure if thats alot or not for tubes? They have dark brown burns on parts of the glass where metal touches. I had a Voodoo mod and adjustable bias installed around 8 months ago so I will be biasing it myself for the first time. I may get a Weber biasrite unless its not necessary with just a voltmeter. I also want to try try my Mesa el34 svetlanas. and need to bias for that as well. I am not as interested about doing alot of math as just what the number should read on the display of the biarite or a voltmeter. Any help is very much apreciated. Thanks
Do you happen to know the bias numbers for Mesa 6l6/ EL34 tubes or possibly Ruby 6l6mstr tubes? I would like to compare these tubes but do not want to mess up the amp. I know the Mesa tubes are real close as the Mesa is a fixed bias amp originally. I just need to check the tubes I have to see what tubes contains "The tone" Thanks alot

 

[mrid]

Re: 6l6 tubes:How many hours before changing? & Bias questions

You need to figure out the plate voltage. There is no magic value that is right for every amp.

 

[KLINKDETROIT]

Re: 6l6 tubes:How many hours before changing? & Bias questions

How do I do that? and does it vary per tube? I hear the mesa 454 svetlana is really higher bias than the mesa 430 even though they are both used in a fixed bias amp.

 

[sweet_lou]

Re: 6l6 tubes:How many hours before changing? & Bias questions

I don't know about tube life but here is some bias info


https://forum.seymourduncan.com/showthread.php?t=27957

I will be contacting Bob @ Eurotube about the tube #s

 

[Hellion]

Re: 6l6 tubes:How many hours before changing? & Bias questions

Ya know, when they're not sounding right to you anymore, it's time to retube. I like Ruby Tubes, but I've heard they're inconsistent.

 

[some_dude]

Re: 6l6 tubes:How many hours before changing? & Bias questions

Ya know, when they're not sounding right to you anymore, it's time to retube.

+1. I think my last set lasted about six months....now idea how many hours though.