Another question. Why not matched EL84 quads?

[Murphy Slaw]

Huh?

Guess it doesn't matter. Any ole' tubes will be just fine........

Best of luck.

Murph.

 

[ThunderMonkey]

EL84's are used in Class A amps exclusively.
Class A meaning there is no push/pull circuit or Class A/B like most amps.
There's alot more to it but they don't share the same circuit like A/B duets so they don't need to be matched.

 

[Rocky]

Lots of people assume that EL84=Class A. This simply is NOT the case. My Nomad 45 uses 4 EL84's and it isnt Class A

I use to have a Marshall DSL 401 that used EL84's and it wasnt Class A either.

 

[Guitarzan]

Ruby and GT do matched EL-84 quads.

 

[ylo]

Most (but not all) amps with EL84s use cathode bias (self bias) on the power tubes, and matching the tubes is probably not as critical as on a fixed bias amp. Unless you are talking about a single-ended design (one output tube), EL84 guitar amps run Class A/B push-pull, not really Class A, despite the marketing claims.

I have never tried matched tubes in my LSS (which uses EL84). In my push-pull 6L6 amps, the only difference I have ever noticed with matched tubes is a little more headroom.

 

[fatboy135]

EL84's are used in Class A amps exclusively.

Totally wrong, el84 are used on Class A ( bad called single ended ), Class B, Class AB, 6v6 are also used in that topologies, the only truth is that in class A amps it is better to use el84 due the few watts they dissipate, you could use a 6550 on a class A but maybe you will lost a lot of money with your electrical company.

On the other hand I always recomend to match all the power tubes in push-pull circuitries

And yes I have noticed a bit fuzzy sound using non matched tubes, but sometimes that fuzzy sound helps you for a new metal sound :lol:

 

[Guitarzan]

Hey Gordo! Where have you been?

 

[fatboy135]

I have been working too much
**** GAS I´m spending my life for the GAS

 

[Strat N My Stuff]

So is the answer ........ Matched EL84's produce a cleaner, higher headroom on channel one of the LSS. (I assume the settings would be 15/30 watts, diode rectification, as that would be where to start for the most clean headroom anyway, right?!)

To my knowledge, Mesa doesn't offer them as "matched sets", so it would require GT's, Teslas or other brand to be named?

BTW, these are supposed to be questions. Later. Jeff