Posted by tnuctip [ 64.12.116.14 ] on December 20, 2004 at 13:35:48:
In Reply to: Re: how simple do you want to get? posted by Wayne Parham on December 20, 2004 at 12:04:56:
Hey-Hey!!!,
On the all valve: The PS should remain shunt regulated,and it will probably be fairly easy. A single pentode configured as a curent regulator to feed the VR tubes is about as simple as the MOSFET version.
The Amplifier active loads are not so easy with a pentode. The g2 circuit in parallel with the plate is the issue( as I see it now ). Sooooo, how about a cascoded pair of triodes? Series curent path and high AC impedance, and still able to retain the mu-follower's signal output. It would probably be best to use a cascoded MOSFET CCS to generate the Ec2, but that would be th extent of it, and that is two DN3545N3 and three resistors...
I have heard another all valve, regulated linestage and it was really good. this should be able to match or better its performance with a simple signal path like my hybrid.
I have another in the planning stage to use the 10Y as the amplifier valve, and this PS and load idea is how it will get done. It will have a few more valves sticking up through the top, but that's OK with me.
You heard it here first!
Of course I'd keep the 816-rectified, L-C unregulated supply...
regards,
Douglas
!