QSC style single supply

[Gold_xyz]

I want to rebuild my old 100W amplifier with BDX66C/67C
which advantages do I have if I use a scheme as the famous amplifiers QSC?

Filter capacity is 4700/2 = 2350uF

[Jan Dupont]

Famous in what way ?

Only advantage is that you only need a single rail power supply.
On the other hand, you get two large caps in the signal path

[Eva]

The capacitors are *always* in the "signal" path, no matter if the transformer has a center tap. However, they may be inside or outside the global feedback loop.

In that particular schematic the capacitors will be always inside the feedback loop, no matter if ground reference is taken from capacitor mid point and feedback from the emitters or vice-versa. Some means of DC balancing is required, though.

[Gold_xyz]

Originally posted by ACD
Famous in what way ?

Only advantage is that you only need a single rail power supply.
On the other hand, you get two large caps in the signal path

Famous at least for the schematics...
(My face at the first look of these schematics : )
This configuration can resolve the start amp bump.
-experiments coming soon -

Originally posted by Eva
The capacitors are *always* in the "signal" path, no matter if the transformer has a center tap. However, they may be inside or outside the global feedback loop.

In that particular schematic the capacitors will be always inside the feedback loop, no matter if ground reference is taken from capacitor mid point and feedback from the emitters or vice-versa. Some means of DC balancing is required, though.

Yes, for my amplifier I need to added a small capacitor for feedback
line. Resistor of feedback R15 is 5.6K
Schematics:
From Italian PHILIPS ELCOMA (1981)

[richie00boy]

I would add balancing resistors across each cap. Other than that, interesting!

[jaycee]

Surely this is bad news if one of those caps fails ?

[richie00boy]

How is it any worse than if a cap fails in a 'normal' PSU?

[Gold_xyz]

This solution in my amplifier not eliminate the bump at start.
(when the capacitor are discharged)

[richie00boy]

There is probably nothing you can do. You should post your schematic of amplifier

[Gold_xyz]

Originally posted by richie00boy
There is probably nothing you can do. You should post your schematic of amplifier

schematics can be found here :
From Italian PHILIPS ELCOMA (1981)
and here:
http://ck703.altervista.org/subdir01/philipselcoma.html

I try to rebuild my old amplifier100W with bootstrap and single supply.