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RE: Medium power SET + minimonitors

Posted by kurt s on December 1, 2007 at 09:29:10

In Reply to: RE: Medium power SET + minimonitors posted by sheldone on December 1, 2007 at 08:30:14:

I have built a 45 amp that produced 2.5 watts running class A2. I even did that without a follower. I just ran a 6H30P driver at 15 mA CCS current and when it swung high that big driver current all fed into the 45 grid. No FET or cathode follower was actually required, although it would have been better with it through the zero Vgk region if it had, with a smoother transition due to a lower impedance drive.

A 6H30P has a bit too little voltage swing for 15 watts into a 300B, however, so it would look like a better way to go would be to have another stage added with another power tube driving the 300B. I could add a 45 stage and maybe a high current interstage transformer to do it. Unless using that SLCF circuit for a follower, I have my doubts it will be transparent enough for my tastes.

OTOH, instead of adding circuits that tend to degrade performance of the sound quality and probably getting maybe 10-12 watts, the only other option I can think of is that 300BXLS that will do 15 watts class A1. And even then, I could make that class A2 and pump it up to 20 watts or thereabouts if I could find a suitable OPT.

Just thinking out loud. Thanks for the suggestion.

Kurt

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