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In the Forum: Melquiades Amplifier
In the Thread: Single-stage Melquiades vs. DHT amps
Post Subject: Optimal operation of 2A3: an experimentPosted by drdna on: 2/14/2009
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 floobydust wrote:
[The Moondog amplifier has] a higher B+ voltage (350 volts) with a 1K cathode bias resistor and the 2.5K load.


 Romy the Cat wrote:
...the most proper operation of this tube will be at 275V on plate and 4.1K load.


 floobydust wrote:
3.5K is the optimum load. I prefer ~290 volts on the plate (plate to cathode measurement). I have a 350-volt plate supply, a 3.5K primary OPT, and an 866 ohm cathode bias resistor (bypassed). Pd is 17-watts, cathode bias current is 58ma and it puts out a solid 4.5-watts.


So it would require a new OPT to be made with around 3.5-4K primary impedance. The power the amplifier puts out is already far too much. I always have the volume dial around 1-2, so this will be okay. I don't have such an OPT on hand so I will need to buy one...

Will that be an adequate test or would you suggest changing the values of R9 and R10 also?

Adrian


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