I'm looking to pick up a pair of matched Mullard el34's for a marshal 18watt. What should I be looking for in the numbers people are posting about the matching?
are these matched well?
mullard el34
are these matched well?
mullard el34
Marshall 18W uses a pair of EL84
And matched pairs aren't so necessary for guitar amps. Just so long as you can bias them properly.
And matched pairs aren't so necessary for guitar amps. Just so long as you can bias them properly.
webelo said:
A small number of $. 😀
More seriously:
You probably don't need matched valves.
A single point measurement is only useful if it's at your operating condition.
The AVO CT160 gm measurement is based on a very dubious assumption.
webelo said:
Yikes ... NOS tubes are expensive!!
Personally, I recommend getting tubes from a vintage tube amp tech. Fortunately, there's one in my town that's very helpful: Larry Rodgers at (239) 649-8799.
Last time I was there he had a Ceriatone TMB in for repairs and new tubes. It's an 18-watt that sounded very cool!
Re: Re: matched tubes?
Let me mention a couple things:
1. Current matching of the valves/tubes is a real necessity in a Marshall since there is no individual bias adjustment. Tubes matched for cathode current are a requirement.
2. In discussing single vs. multi-point measurements and the way a CT160 measures Gm - it's not really relevant here. The absolute value(s) of Gm is not really a concern, it's Gm relative to each other that may be important. So as long as the method of measurement is consistent it's fine.
Besides, some players prefer mismatched Gm, they like the tone better. But current matching is a must.
The tubes on the eBay listing would have likely been fine.
EC8010 said:
Let me mention a couple things:
1. Current matching of the valves/tubes is a real necessity in a Marshall since there is no individual bias adjustment. Tubes matched for cathode current are a requirement.
2. In discussing single vs. multi-point measurements and the way a CT160 measures Gm - it's not really relevant here. The absolute value(s) of Gm is not really a concern, it's Gm relative to each other that may be important. So as long as the method of measurement is consistent it's fine.
Besides, some players prefer mismatched Gm, they like the tone better. But current matching is a must.
The tubes on the eBay listing would have likely been fine.
Ive been ripped off a couple times on eBay. You're much better off buying NOS tubes from reputable websites like AES or TubeDepot.
TubeHead Johnny said:
That wasn't what he was asking, nor what I was recommending. I just meant the matching listed would do fine.
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