- Jan 5, 2009
(Mods, if this is in the wrong place, please let me know)
LDMKIV tube rolling question from a newbie.
Bought my first tube to roll with: a pair of Mesa Boogie EL84/6BQ5s, recommended by a local dealer. They aren't working right: there's hardly any sound, just horrible static.
They are seated correctly, and I have de-oxidised the pins. They do not appear to be damaged or dead (silver top, no purple glow etc), and I bought them from a reputable dealer. Stock tubes working fine, with good sound, so it's not the amp itself. Before I send them back: it occurs to me that I may need to change the jumper switches. But I don't know what these look like, and Google is no help. Neither unfortunately is the LD manual/reference guide.
Do I need to change the jumper switches? If so, where are they? And please don't say 'next to the capacitors' - assume I'm an idiot please! Muchas gracias
As far as I have been able to determine the EL84 valve is not a drop in replacement for the LD MKIV.
Here is a link to the owners manual that gives some info on tube rolling, however the power tubes don't include jumper settings for alternate tube types.
https://www.dropbox.com/s/biytahabdg1xs1c/Little Dot MK IV SE Reference Guide.pdf?dl=0
I would stick with the power tubes that shipped with your amp. If you want to experiment with different flavors of sound, its the driver tubes you want to roll. They have far more effect on the sound.