Posted by Tnuctipun [ 64.12.116.14 ] on March 03, 2005 at 18:10:09:

In Reply to: Re: More amp design considerations posted by Cheetah on March 03, 2005 at 17:26:46:

Hey-Hey!!!,
The beauty of this topology is its adaptability to power stage valves.

The front end should be a cascode diff amp. Two 5687's are a fine choice. They have low enough plate z to allow an Ec2 of ~70V, and gm for enough gain. Figure B+ of ~300, and plate loads of 25-30k.

Special voltage ref for Ec2 to the common cathodes instead of the traditional ground. Building a voltage reference is no biggie. Just assume it is as I say for the time being....
regards,
Douglas

Replies:

• Input stage - Cheetah 14:33:46 03/04/05 (3)
  • Re: Input stage - Tnuctipun 14:41:00 03/04/05 (2)
    • Re: Input stage - Cheetah 14:46:28 03/04/05 (1)
      • Re: Input stage - Tnuctipun 20:19:44 03/04/05 (0)