Quote:
Originally Posted by Analogdino
Quick update:
Tried a pair of good 5881's, bias optimized, even balanced the cathode currents to around 1.5 mA.
No good!
Max p-p volts across 8 ohms = 40 VAC, 200 Hz.
Thus, power = 25 watts.
Pretty much same as 6L6's, not really surprised.
We soldier on...
Cheers,
Roger
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The 3500R presented by the existing OPT with 8R on the 8R tap is rather a steep load for the 6L6 family run in the present conditions. Should be more like 6K which I had used.
Try increasing the secondary load R on the 8R tap gradually, say 10R, than 12R & so on. You may see an increase in developed power, a useful experiment. Better still, do something similar on the 16R tap where the OPT copper is better utilized.
I like to set the load lower than the published optimum. The loudspeaker load is complex with its frequency extremities at quite a bit above that published. Some tests reveal the 3H developed in a PP OP is less when the load is set lower than the optimum published.
We don't listen much to ideal resistance loads!! All easy to try.
Cheers, John