#1
So I got a used Mesa Dual Rectifier amp with Mesa 4x12 and all the goodies ..... I've played three practices with it roughly 3 hours loud per practice .....

so I finally got it in the house looking at things and trying to get more familiar with it and I noticed it has two KT77's in the outer socket and JJ 6v6's in the two inner sockets ...But .. the Bias setting is set on EL34 and had tape over it so you couldn't move it ...... am I hurting this thing running it like this ?? ..... it sounds beautiful how it was set up when I got it , when I asked about the Bias switch he said it was set right on the EL34 position but after talking to a music store owner (amp tech was out) he said those are 6L6 tubes ... should the amp Bias switch be on EL34 or 6L6's ??


thanks , Eric
#2
KT77 is in the EL34 family not 6L6. 6V6 is a smaller tube and I belive www.eurotubes.com sells kits like this.

The store owner doesn't have a clue, Yes the stock tubes are 6L6, but yours obviously doesn't have them.


EDIT: yep here is that tube combo
www.eurotubes.com/store/pc/viewPrd.asp?idproduct=514&idcategory=151
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
Last edited by Robbgnarly at Feb 6, 2016,
#3
In your situation I'd contact Mesa and see if that type of Config is supported or will break anything without being modified.

Any way to get in touch with the previous owner and ask if anything inside the amp was altered?

You can always open it up and start cross referencing components to the schematic and see what you have.

Mesas are generally over built like a tank.

Ah the joys of buying used!
Guitars:
Jackson Kelly KE3 - MIJ (Distortion/Jazz)
Jackson DKMGT Dinky (EMG 81/85)
ESP E-II Eclipse Custom (JB/'59)
ESP LTD EC-1001FR (EMG 81/60)
Fender MIM Strat

Amps:
Mesa/Boogie Dual Rectifier Roadster 212
Laney IronHeart IRT-Studio
Peavey Vypyr 30
Peavey ReValver Amp Sims
TOOOO many T.C. Electronic Pedals. . .
#4
Quote by metalmingee
In your situation I'd contact Mesa and see if that type of Config is supported or will break anything without being modified.

Any way to get in touch with the previous owner and ask if anything inside the amp was altered?

You can always open it up and start cross referencing components to the schematic and see what you have.

Mesas are generally over built like a tank.

Ah the joys of buying used!

the amp will be absolutely fine.

Mesa isn't going to condone using that tube configuration. They will not even suggest using JJ tubes, only their own re-branded ones
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#6
Quote by Will Lane
So the switch is set to EL34, KT77's are equivalents. Are the 6V6's safe?

yeah read the bias details in the last link:

These amps are fixed bias with no adjustment other than the switch to go between EL34 mode and 6L6 mode. 6L6GC's, KT66's and KT88's are run in the 6L6 mode.

EL34's, 6V6S's, E34L's, KT77's and 6CA7's are run in the EL34 mode.
2002 PRS CE22
2013 G&L ASAT Deluxe
2009 Epiphone G-400 (SH-4)
Marshall JCM2000 DSL100
Krank 1980 Jr 20watt
Krank Rev 4x12 (eminence V12)
GFS Greenie/Digitech Bad Monkey
Morley Bad Horsie 2
MXR Smart Gate
#7
the local store owner did say contact a Mesa service center to be sure since his tech was out ...... I knew Mesa would want they're tubes ..... I love how it sounds and don't want to change anything if the Bias switch is set correctly , my Band mates love it too .....

thanks guy's
Eric
#8
Rob , that link is exactly how my amp is set up , thanks again ....... it sounds incredible with the Mesa 4x12 cab and those tubes