Mesa Branded STR-415

[zodiac272]

Will two matched pairs of the Mesa brander STR-415's work in my MK IIC? The current is matched within the rang, but will they be at or under the required plate voltage or whatever it is? they are slightly used, and I guess what I'm asking is will they work like a set of new mesa tubes? or will i need to have the bias checked

thanks

scott

 

[dodger916]

Matched pairs or a matched quad of Mesa-branded STR415 should work safely in your IIC. Mesa's are fixed-bias amps, so rather than adjusting the amp's bias to the tubes you install tubes that will operate safely within the amp's fixed bias. Being Mesa-branded means they meet the specs of the amp. It's been my experience that 415s will work better than new-production Mesa tubes in your IIC. After all, the amp was designed when 415s were THE tube.

If your amp is Simul-class and you know the idle current draw of the tubes, put the lower current pair (usually expressed in milliamps) in the outer sockets.

 

[94Tremoverb]

They will be fine. As dodger said, if you know the current draw you should probably put the lower ones in the outer sockets, you'll get slightly better life expectancy this way, but if you don't know then don't worry about it - they will all be well within the safe range. 415s are some of the best and most long-lasting 6L6s ever made, so I wouldn't be in the least worried that they're slightly used. I've been using old (tested) tubes in my amps for over 20 years, I very rarely buy new ones - I stopped once the new ones were all Chinese or Russian, even though it's not as hard to find NOS US or European ones now that we have the internet. I don't have any problems with reliability at all.

 

[zodiac272]

Nice. I figured since they were Mesa branded they would work, but I just wanted to double check.

thank you!