VanWhailin

Hey all,
My Marshall 2204 needs new tubes, so I'm about to replace the preamp and power sections in one go.

Not really looking to increase gain, but I want to get the maximum balls out of the amp and almost to cut back on the "fizzy" sounding preamp distortion. In other words, get the thing to sound more "plexi-ish" and less like a jcm800 if possible.


3 questions for all of you who know about this stuff:

What difference would going back to 6550's VS sticking with EL-34's make, and what kinds of tubes (new or NOS) have you found produce the best sound of both variations?

what should I know about changing the preamp tubes, and again, what have you found gives the best sound?

how does one "bias" the amp when changing tubes, and what difference does the matched pair make?

My problem is that i have no idea how the biasing concept works.
The amp was converted to run el-34's, but I am uncertain if I should keep it that way.

Let's hear some of your input!

Cheers!

VW

Marshall Amps

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HumanJHawkins

If set up right, EL34s are reported by many to be more "musical". Though everyone's ears are different. I believe El34s are considered 25 watt tubes. 6550s are 30 watt tubes so you might end up with a 120 watt amp, though you would not notice the difference by ear.

If your transformer is up to the load, you'll only have minor tweaks to run 6550s. But some transformers will handle EL34s well, yet not support 6550s well.

I'm not an expert. I've just been talking to some knowledgable transformer people about this recently, so thought I'd pass on what I've heard.

bluefrog

good value (valve) from money: JJ el34.
otherwise svetlana =C= el34 or TAD El34.
gues yr amp is made for El34, not experiments pls.