Posted by Tnuctipun [ 64.12.116.14 ] on February 19, 2005 at 16:15:01:
In Reply to: Re: Some thoughts...tubes posted by Damir on February 19, 2005 at 15:23:54:
Just out of curiosity, what is a pair of matched pairs of 300B going for these days? I know WE is ~$1k/pair. Seems sort of nuts, I'd rather build an 845 amp. The other end of the spectrum is where? ~$200/pair? more or less?
I have no problem with building for 300B's. The only thing I keep running into is a perception based issue. 4k is a reasonable( and WE specified ) anode load for a SE 300B. Extending our 'double the SE load for PP', means we wind up at a 8k a-a OPTx. Not that this is altogether bad. I can think if a few really good OPTx's in this general neighborhood.
According to WE between 6 and 8k is a reasonable PP load for this valve. I do put in my vote for higher a-a load. Power output goes from 20W for a 4k a-a to ~13 for a 10k load. 6k comes in at ~16 Watts. Almost splitting hairs at the higher loads, hence the vote for better damping afforded by a bigger( higher numeric ) load.
Individual valve filament TX is easy, so is a -100V fixed bias supply. PS will be a big L-C supply no matter what amp we decide to put behind it.
regards,
Douglas
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