Best Source for ‘Matched’ Tubes?

PDC

PDC

Well-known member
Hello all - I’m seeking some experience and input as to which tube supplier has the best / most closely matched tubes?

I just went through 2 different allegedly ‘matched’ quads of EL34s from 2 different suppliers. In each quad, I had a pair that was very closely matched and one way lower and one way higher (?) For example, once I had bias settled in at 30 and 31 for the closely matched pair, the other two tubes were 25 and 37 mA respectively.

After hours of tube rolling and amp warming and cooling, I finally found a pair from each quad that settled in within 2-3 mA across the board - but it took forever. And now I have 4 mis-matched EL34s left over. I ‘might’ be able to narrow down the closest pairs from what’s left - but they could never function as a matched quad.

Hoping to avoid this frustration going forward and wondering where to source reliably matched glass in the future..

Thank You!
 
PDC":3irn5j30 said:
Hello all - I’m seeking some experience and input as to which tube supplier has the best / most closely matched tubes?

I just went through 2 different allegedly ‘matched’ quads of EL34s from 2 different suppliers. In each quad, I had a pair that was very closely matched and one way lower and one way higher (?) For example, once I had bias settled in at 30 and 31 for the closely matched pair, the other two tubes were 25 and 37 mA respectively.

After hours of tube rolling and amp warming and cooling, I finally found a pair from each quad that settled in within 2-3 mA across the board - but it took forever. And now I have 4 mis-matched EL34s left over. I ‘might’ be able to narrow down the closest pairs from what’s left - but they could never function as a matched quad.

Hoping to avoid this frustration going forward and wondering where to source reliably matched glass in the future..

Thank You!
Click to expand...

Sorry to hear this, but I've experienced this with many top sellers. I finally went out and bought tube testers.

To answer your question, tube depot has been pretty good with matching.
 
Mismatched tubes produce asymmetrical clipping and more even order harmonics, looser bass, and “give” under drive. I prefer about 10 ma myself, and even use different cathode bias resistors in my custom amp to produce this effect.
 
All the Apex matched quads I've had in various amps have been within 2-5 mA of one another. Amplified parts sells Apex matched pairs/quads.
 
+1 to getting a tube tester especially if you have several tube amps. You can sometimes find a used Orange Valve Tester on fleaBay or reverb.com for under $400.
 
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