Tube Question

[Spud]

Having recently become the proud owner of a RoadKing combo, I noticed that two of my 6L6 power tubes have white writng on them and are marked STR430 and the othe two 6L6's have black writing and are marked STR440?

Whats the difference and will it effect the tone of the amp?

The two tubes nearest the rectifier tubes are the STR440's if this helps.....

Thanks in advance

Spud

 

[Bren10]

Man... this is just me saying this but I'd ditch those buggers straight away. You can get a set from Eurotubes or Mesa that will work and then you'll know what you've got.

To answer your question directly, I can't find any tube data on either of those numbers. Who knows? As far as tone goes, Mesa amps have no bias adjustment. They want you to buy tubes within a certain spec. That way they can guarantee that you'll get consistent tone. It's not really a bad thing.

The problem is that so many mesa owners think that their amps are "Self Biasing" or something and they put any old tubes in there. When this happens, there's no telling what's going on with the bias.

Anyway, I don't know if those tubes are to the right spec or not but if you put some in that you know are... I bet you'll hear the difference.

That's cool that you got a road king, by the way. I think those things are so cool.

 

[cnumb44]

The STR tubes are Mesa's. The 430s were a Russian manufacturer and the 440s are Chinese (I think). Mesa can sell you a set of matched 440s and you'll like the sound. I think the white and black stripes are like the warmer ratings the Groove tubes uses.

Bren10 is right, Mesa fixes the bias so you need to get tubes that will operate at that specific bias. Mesa will definitely get you the right tubes, but a number of other tube stores will sell you Mesa spec'd tubes, just be sure to tell them what amp they are for.

 

[Spud]

Thanks guys.

I'll contact Eurotubes and see what they say.