PS with boosted rails for IPS, VAS and Pre-Drivers

[jkuetemann]

I have a selection of reclaimed power transformers from various pieces of gear and am looking to make a power supply for a smallish ~25W amplifier. I have never before bothered with a design with boosted rails but these old transformers have two separate secondaries that look like it would be a decent idea. They have a 20Vrms main secondary and a lower current 11Vrms secondary. I'm thinking simple RC filtering for the 20V secondaries and using a capacitance multiplier on the boosted rails, the 20V+11V. This will give me quiescent rails of about +/- 26V for the OPS and +/- 36V for the IPS and VAS.

Any opinion if 10V extra per rail would be too much? Any specific suggestions? See attached image. Obviously fusing will be included, just not shown in the diagram.

[AndrewT]

looks good to me.
Needs more work on how you connect all the zero volts together.

[jkuetemann]

Originally Posted by AndrewT

looks good to me.
Needs more work on how you connect all the zero volts together.

Yes, I definitely agree that how it is drawn and how it should be built aren't the same thing. It will likely end up something like 'star on star' to keep the heavy current pulses localized and provide a quieter return for signals. I guess it is considered good form to draw it exactly as it will be built, not just showing the required connections.

I haven't inserted any bypasses or snubbers at this point, at the target level of voltage and current would they be of much benefit?