Posted by Tnuctipun [ 172.154.216.226 ] on May 20, 2005 at 06:44:59:

In Reply to: Push-Pull 300B posted by Russellc on May 16, 2005 at 18:07:32:

Hey-Hey!!!,
One such beast is on my list of amps to build. It is a bit far down the list for a few reasons, the main one being I find dealing with Pentodes a bit more fun( and some Tantalum anode DH pentodes are in my sights.

An 8k a-a with 20W of core rating would be my choice. 10k a-a is twice the SE load of 5k and cuts maximum power just a bit more than 8k a-a. E-Linear taps at ~10% and B+ ~370. Higher load would allow a higher B+ w/o leaving class A and leave more volts for the front end. Keep it absolutely Class A bias, perhaps even to the point of limiting power a bit. 12 or 14 Watts is hard to tell from 17...

For the front end, a differential pair of 6C45's look quite good. Hard to get a matched pair I am told, but I have heard them built in PP DHT amps to good effect.

Lots of options for sure, and with good OPTx design, it will be hard to make it sound bad...
regards,
Douglas

Replies:

• 6S45Pi - Damir 08:13:05 05/20/05 (8)
  • 6S45Pi diff pair input signal headroom - Tnuctipun 08:55:29 05/20/05 (7)
    • Re: 6S45Pi diff pair input signal headroom - Damir 15:05:07 05/20/05 (6)
      • but, but, but... - Tnuctipun 19:10:03 05/21/05 (5)
        • Re: but, but, but... - Damir 03:00:29 05/22/05 (4)
          • so then.... - Tnuctipun 08:27:12 05/22/05 (3)
            • Re: so then.... - manualblock 19:01:52 05/23/05 (2)
              • Re: so then.... - Tnuctipun 20:08:29 05/23/05 (1)
                • Re: so then.... - manualblock 06:37:01 05/24/05 (0)