Tube Amps / Music Electronics
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|previous: Per Hi!
|9/2/2000 1:32 PM|
|EDGAR||Re: LANEY LH50R!!!!!!!|
That Laney, is it with two Sovtec 5881 output tubes?
I'm quite shure it runs in some grade of class AB.
(I haven't seen the shematics on it, but I would really like to do it! Is there anyone who has it?)
Very few guitar amps runs in class A, and I think it's almost only amps with EL84:s that do.
I can't tell You about the sonic differences between class A and AB, but I guess there's someone out there who can!?
If You want to compare it proparly, You have to do it in the same amp, or else You compare a lot of other things at the same time. But that's a little difficult, since AB amps usually have higher plate voltages than class A amps.
If the Laney sounds just good, there ain't no reason to change tubes, is there? EL34 and KT88 are more expensive then 5881, (KT88 much more!) and EL84 isn't an option in this amp, unless You put in a couple of the Ruby Tone Bones. But then You get only 18 Watts at the best.
If You want to try EL34:s for example, which is the most natural choice, don't just put it in!! You probably have to get the amp a little rewired first, and the bias has to be adjusted.
What You CAN put in, is different types of 6L6:s.
That's right, You (normally) don't have to adjust the bias in class A amps. It's not even possible, unless You change some resistor(s) in it! But it's a good idea to make sure the tubes are proparly matched, as always.
(Svensk, Per? Ta gärna kontakt direkt med mig i så fall!)