can I use 3, 8 ohm cabs with the sat by 2, 8 ohm cabs in the 2, 4 ohm sockets and 1 8 ohm cab in the 8 ohm socket
simul sat question
- Thread starter JD
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That's not a recommended setup - from the amp's perspective, you're doing the same thing as plugging a 4-ohm cab into the 8-ohm socket - but it won't hurt anything.
You'll lose power (about 30% or so) and dynamics, but it'll work.
A better approach would be to make or buy an adaptor that would put two of the cabs in series for 16 ohms. Then plug that load into the 8-ohm jack and the remaining single 8-ohm cab into the 4-ohm jack. That would result in an optimum match.
You'll lose power (about 30% or so) and dynamics, but it'll work.
A better approach would be to make or buy an adaptor that would put two of the cabs in series for 16 ohms. Then plug that load into the 8-ohm jack and the remaining single 8-ohm cab into the 4-ohm jack. That would result in an optimum match.
thank you
I also tried a pair of e34l jjs tubes in the outer sockets but the sound was awful very nasely like I was overloading the input with to much high frequency do I need special tubes the guy I bought the tubes off said they were a touch hotter than the mesa tubes but they would work fine any ideas
This is only a guess, but I suspect you were hearing extreme crossover distortion.
The 'Simulclass' sockets in Mark IVs (and Simul Sats) aren't well-matched to most EL34s. If you look at most Mesa amps that can switch bias between 6L6 and EL34, you get around -55V in 6L6 mode, and around -39V in EL34 mode. And since just about all the amps use the same power transformer now, it's a pretty good apples-to-apples comparison.
I have a recent Mark IV, and it has about -53V on the inner sockets, and about -49V on the outers. That outer number will have most any EL34 running EXTREMELY cold.
I have a bunch of "Siemens" EL34s, and I probably went through forty of them before I found a pair that idled properly in the outer sockets.
The 'Simulclass' sockets in Mark IVs (and Simul Sats) aren't well-matched to most EL34s. If you look at most Mesa amps that can switch bias between 6L6 and EL34, you get around -55V in 6L6 mode, and around -39V in EL34 mode. And since just about all the amps use the same power transformer now, it's a pretty good apples-to-apples comparison.
I have a recent Mark IV, and it has about -53V on the inner sockets, and about -49V on the outers. That outer number will have most any EL34 running EXTREMELY cold.
I have a bunch of "Siemens" EL34s, and I probably went through forty of them before I found a pair that idled properly in the outer sockets.
thanks again AdmiralB
No problem!
I think the Mark IV (and Simul Sat) just aren't good candidates for EL34s unless you can go through a lot of tubes to find a pair of 'freaks' that work well.
Or you mod the amp - but those are near the bottom of my list of amps that I would enjoy working on.
I think the Mark IV (and Simul Sat) just aren't good candidates for EL34s unless you can go through a lot of tubes to find a pair of 'freaks' that work well.
Or you mod the amp - but those are near the bottom of my list of amps that I would enjoy working on.
disassembled
Well-known member
AdmiralB said:
No way! :lol: Mesa's are laid out like the old 70's Cadillacs.....ok maybe not but yeah I know how you feel. If they add anymore crap on their boards it will probably collapse from the amount of holes in the PCB.
Greg
can any one tell me how to change the bias on the outer tubes to run jj el34s
disassembled
Well-known member
You would have to do some pretty good modding to get 2 seperate Bias circuits in place (one for the outer and one for the inner pair).
I don't recommend it and just be happy with 6L6's
Greg
I don't recommend it and just be happy with 6L6's
Greg
will mesa el34s work
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