JK-47
100+ Head-Fier
- Joined
- Jan 2, 2015
- Posts
- 374
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- 68
I try to stay away from the Cryo treated tubes. I recommend platinum or gold plated tubes.
I thought platinum and gold grading was how closely matched a pair of tubes are... One ebay seller grades platinum <5%, and gold <10% variance between mutual conductance measurements... Upscale Audio's definition is slightly different...
http://www.upscaleaudio.com/grading-and-matching-small-signal-tubes/