Thoughts on the old Schade PP series feedback?

[jhstewart9]

Here is the cct with 50% NFB. DF greatly improved.
But the drive requirement has increased as well.
All fixable with boot strapping, just as it is in the
McIntosh & Electrovoice.

The stray C's & L's will have to be fixed in the real
thing.

 

[CSandrelli]

This can be obtained with a proper project without any problems also including the FB loop out-in.
The quality of project and OT is the secret, no way.
And still I can't see a proper test results done on desk.

Walter

Listen. I have problems with my eyes and I have no more equipment except an old Unaohm and a home-made signal generator.
If you want to try to build it here is the .asc file. The coil on Gs is essential. Diodes D1 and D2 must be bridge rectifiers. The 27 1N4148 series is to be tried instead of the Rk 270ohm. However, some values should be adjusted based on the type of output transformer used, but it is the starting point.
I do not take responsibility for construction failure.

 

[waltube]

If you want to try to build it here is the .asc file.

Thx but it is not my interest now.
I have a lot of stuff to use for Schade config, in case.
But it is interesting that it is difficult to see some real test on lab of this config.

Walter

 

[waltube]

Here is the cct with 50% NFB.

Have you built it?
In case have you check the performances?

Walter