wrong bias setting on a dual rec... PLEASE HELP

[disassembled]

The disrespect I spoke of was'nt about the mistake of forgetting the bias select switch! It was towards the disrespect of trying "old tubes like from the late 60's probably & well used"! Seems a bit experimental, no? But hey, it's your amp, not mine! And you never know, some of those old tubes seem to last forever, and may sound sweet! But, without knowing enough about them, I would'nt just try 'em without a little hesitance. That's all! Can I get back on my high horse now? Thanks!

It must be hard as hell to ride a "high" horse. I guess it depends what the horse is high on but I just hope you are wearing a helmet!

Greg

 

[jbird]

Helmet! I like Helmet! :twisted:

 

[Boogiebabies]

nothing blew. and the 6L6's were definitely old, like from the late 60's probably & well used. thanks for putting my mind at ease Siggy.

I'll accept the above post! Most of it anyways? What gets me is the disregard towards putting unknown, old tubes in; "Like from the late 60's probably, & well used"! And now someone's worried about the well being of they're amp? I tell you what, go get a meter, and start poking around in there! With the disrespect you have towards an instrument made to last forever, maybe you'll get a little jolt of reality! How 'bout not treating your amplifier like a toy! :roll:

get off the high horse. i was using ge 6L6's that were matched pairs, & it ended up sounding great. and it's not disrespect toward my gear if it was an honest mistake.

I don't think jbird meant any disrespect with his comments. If you read it, it is basically offering you guidance on the worst possible thing you can do to a tube amp. When you put unkown, old, worn out and seriously mismatched tubes in your amp you are gambling with an expensive amplifier. Also, if your new to the nuances of tube amps, read some technical books. Another point jbird made in sarcasm was about poking around in your amp. Another thing not to do. The nice thing is that even a novice can invest in a bias meter and at least see where thier amp is running. If you have cold 6L6's and want to run them hotter, you could possible run them in the EL-34 bias mode. DR's are pretty consisten at 460 plate volts, so 40-45ma from a 6L6 will be fine. Even if jbird was riding a high horse, he rode it with the best of intentions. He mad some valid points and at the end of the post, he rolled his eyes. A lot of guys arounf here are very genuine, but you have to get used to everyones personality. Jbird's a good guy, it just may take a while for him to warm up to you.

 

[mutha]

What about current per tube when Vacuum Rectifier and Spongy Mode are engaged together? Is 7-9 mA per tube still enough or not? The same with RK, especially with EL34's

 

[Schmoog]

its important to remember that randy smith and the boys made these amps fixed bias for a reason. reason 1 was making sure that tubes don't die prematurely. reason 2 is they wanted to eliminate the maintenance of a bias adjust. if you want to run your tubes hotter, by all means go ahead. I do with all my amps (havent had a chance to check my mark III yet). but I don't feel the need to put in a pot. all you gotta do is change the resistor. that way you get warmer running tubes, and still don't need to worry about the amps bias.