Bass head tubes

[tota_matt]

Anyone ever experiment with any different tubes replacement in bass heads? I know some people use EL34s instead of certain tubes in guitar heads and such.
Any suggestions on other tube options.
I own a Mesa boogie 400+

[runmikeyrun]

6L6 tend to stay cleaner longer than EL34. If you like dirt and grind with a little less punch EL34 would be a better bet. If you play clean stick with 6L6.

[chillerthanmost]

Not many heads give you the ability to just swap out the type of tube it uses at any given time. You'd have to change resistors, re-bias and even tube sockets. There are a few that are ok with swapping, but for the most part it could require more than just placing the tube in there.

I've owned an Ampeg V4, Sound City 120, Mesa 400+, Sovtek Mig100H, Traynor YBA-1 and Sunn Concert Bass. I ditched them all for my Univox UX1501 which uses four 6550 tubes. I haven't used KT88's but out of everything else, I love me a good USA made 6550 for bass. Gives me exactly the sound I want for bass.

[JimmyM]

If it ain't broke, don't fix it.

[4StringShooter]

The new Traynor 300 watt tuber has TWELVE 6L6 s in it.

[B-string]

Tubes are not light bulbs, the supporting components need to be able to handle a different tube type. You could try a 6550/KT88/KT90 or even a KT120 but if the power trans filament winding can't handle the current draw you'll smoke the PT. The screen and grid circuits may not be optimal, each type would require a different bias. Hope you are getting the idea?
It is your amp, try if you want......your tech will be waiting if things go badly?

[T-Bird]

Hi.

Originally Posted by chillerthanmost

Not many heads give you the ability to just swap out the type of tube it uses at any given time. You'd have to change resistors, re-bias and even tube sockets. There are a few that are ok with swapping, but for the most part it could require more than just placing the tube in there.

^This.

If You know what you're doing, it sure can be done, but unless someone has made the excatly the same mod down to the make of the tube, it's always a gamble.

Class A SE, 2 tubePP, even 4 tube PP it's pretty easy, but when the amount of tubes go up from there, it becomes progressively more difficult and more expensive.

The tubes type isn't automatically a sure way to tell how it will behave, there's just too many variables.

Regards
Sam

[BassmanPaul]

EL34s have a 1.5A heater. 6L6GCs, used in the 400+, have a 0.9A heater. That's a difference of 0.6A per tube. Multiplied by the dozen tubes in a 400+ that's a whopping extra 7.2A that the PT has to supply. How long do you think the PT is going to survive???

Just 'cos a guitar player does such things is no reason why a bass player should!!!