Mesa Boogie F50

[Spence]

Anyone modded one of these?
I find they're a little hard sounding so I've ordered a vintage style alnico speaker for it in an attempt to sweeten it up.
Be interested to hear of any improvements with tubes too.

[Analog Assassin]

No mods here, but I'd like to see what it is...my bandmate has one and it is a really nice sounding amp. Doesn't have all that extra bull that Mesa usually has.

[Spence]

Well, some years on now and I still don't find this amp quite right even with a much better alnico weber speaker.
I'm startimng to think it's like the bastard child of Fender and Marshall. It's like a jack of all trades and master of none. The amp is quite hard sounding and I'm wondering if I can change the power tubes to a more Fender taste.

[MWAMP]

Hard Sounding Mesa Boogie F-50

Well, some years on now and I still don't find this amp quite right even with a much better alnico weber speaker.
I'm startimng to think it's like the bastard child of Fender and Marshall. It's like a jack of all trades and master of none. The amp is quite hard sounding and I'm wondering if I can change the power tubes to a more Fender taste.

Yes they can. I checked this out recently when a amp named an "F-50" could only be made to output about 30W or so using new 6L6 and discovered that the output transformer impedance is better suited to EL34 - not ideal but closer than for 6L6. I measured it at around 4k anode-anode and there was no fault. In fact MB appear to have been making provision for both types (to the extent of tying pin 1 of the output tube sockets to ground to satisfy suppressor grid requirements for EL34s) and not optimizing for either. You will almost certainly need to alter the biasing (lower voltage in all probability) to suit EL34. The output power climbed to about 50W before optimally biasing the tubes.