And while I was at it I saw some 0,22uF Epcos MKV from the same seller. The Epcos will do duty as coupling cap, as I've seen good reports (anecdotal) on them.
I asked Ian (gingertube) what the 470R resistors were for. Because I figured the CCS would take care of everything of the balance.
Here was his answer:
Quote:
The 1K pot is to set balance in the diff amp. The resistance in the triode cathode degenerates the tube gm (Ia/Vgk). Sweeping the pot wiper from side to side varies the amount of degeneration on each of the 2 triodes until they match. This is the minimum distortion condition for the diff amp. As we don't want to throw away gm un-necessarily we don't want those resistance values too high - just high enough to be able to adjust for matching behavior.
For a random sampling of 12AX7 and ECC803S that I had, 1K was too much, 100R was'nt quite enough so I dropped the 470R on each side of the 1K pot which effectively makes that pot about
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