Matching el84's

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Freddy
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Postby Freddy » Fri 10/29/10 2:19 pm

I wonder if you could wire in a 10 or 25 ohm pot between one of the EL84 cathodes and the bias resistor and then dial in a little "unmatching". Then tweak it by ear to taste.
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dotfret
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Postby dotfret » Wed 11/03/10 6:43 pm

The hum is the only real problem - a badly matched pair will hummmm ...

There are some designs that have balance pots to minimise the hum.
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Bacchus
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Postby Bacchus » Thu 11/04/10 1:49 pm

Your ears - that's all. The other stuff can be both misleading, and give you an amp that sounds sterile by comparison. Just pick pairs of tubes that sound great in your amp. Anything else is baloney.
AMEN to that!

OK, Let’s take a step back here and think a bit;

Even if you had a pair of super duper matched tubes within .0001 of a mA, when you’ll play your amp, tubes will not wear out at the same rate so what’s going to happen after a couple of gigs? Your tubes will be…unmatched!
Is your amp going to have a melt down? Nope! Is you amp going to start doing nuclear fission and cause a nuclear holocaust? Probably not. Are the tubes Gods going to come down and haunt you? Well.., if you buy into the tube matching voodoo, then they probably will! :lol:

Hey, I remember as a teenage bringing a Dual Showman to a party to find out that one of the tubes had fell at the bottom of the cabinet and broke. What did we do? We went to the local music store, bought a 6L6, popped it in and partied on, all that without biasing! Heck, I’d never even heard of biasing back then!!

Like Zaphod_Phil said, use your ears and forget about that Groove Tubes (and others) tube matching hype.


Ok, rant’s over.. thanks for listening! :oops:
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BDC
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Re: Matching el84's

Postby BDC » Mon 11/30/15 9:12 pm

I've been slowly building up a small NOS stash, and just purchased a pair of 6P14P-K tubes, match is 10 ma apart.....I appreciate the contributors to this thread, the match was a concern, though not red plating.......it does sound good......and will probably sound better when I change the cathode resister in the amp...... running a little cold......

How far apart is too far on the match?
I gather when there's a hum problem it's too far......but at what point in a mismatch does that tend to be?........
Much respect, and thanks in advance...........
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