In Reply to: Re: ss vs tube ccs posted by Lew on June 07, 2000 at 12:06:27:
To me that is still pretty low, but every amp is an optimization exercise. I would try to boost that current - that shoud give you extra load drive from the output tubes.
That 60k number is pretty high. I would not replace it with a current source - it will not be easy to match that 60k resistance with a tube source.
No further discussions till the 19th - going on a trip.
Which is "pretty low", the current across the 60K cathode resistor in the cf (5 to 6mA) or the bias on the 6C33C output tubes (280 to 300mA)?
You yourself once suggested to me that I bias the 6C33C closer to 240mA (with ca 135V plate to cathode), so I assume you do refer to the current thru the cathode resistor in my cf. Anyway, I cannot fit a tube ccs and am thinking of using a ss ccs, which can easily exceed the 60K resistor in impedance. That was my question in the first place. But are you hinting that I should use a smaller cathode resistor so that more current will flow in the cathode of my (6SN7) cf, when the output tubes achieve proper bias? Have a nice fishing trip.
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