SET Asylum: 845 by Gordon Rankin

You will need gain into the 45 as the 845 really needs to see some voltage to get it started.

My first commercial SET was the Sole 5691-> 300B-> 845. It was big and heavy but man did it drive anything. 25W I was using ProAc Response 2's back then and thought the idea of making a sub 25W amp was silly. Before SET I made El34 and 6550 PP amps.

Then I was at a HAM tube fest here in Cincinnati and Mike Marx sold me a quad matched set of 45 tubes. I made that amp in Sound Practices the CCOS which was a ECL86/6BM8 using the Triode as the gain directly coupled to the 45 grid and then the pentode portion of the 6BM8 was setup as a constant current that biased and lifted the 45 to match the triode. It sounded great into the ProAc's and that changed my whole way of thinking. I stopped making the Sole (well the design was stolen as well) and started on the Cardinal 300B and the Bugle 45 amp.

I still use 45 or VT52 amps in my home system. Except right now I have a pair of custom silver wound 300B amps I made on a wim.

Thanks,
Gordon