Marshall Leach Amp strapping

[krellmk]

Will this work nicely on them PL Amps?

https://worldradiohistory.com/hd2/I...o-IDX/IDX/70s/Audio-1979-02-OCR-Page-0040.pdf

 

[wattsabundant]

I believe I remember seeing this circuit in Audio Magazine sometime in the 70's. The Leach concept is just a phase inversion circuit. As I recall some of the Hafler amps had a strapping circuit. Look up the pro 500. I think the downside is, in bridged mode, an 8 ohm speaker effectively presents a 4 ohm load to each channel. If my recollection is correct it may not be the best application for a P/L amp.

 

[8991XJ]

Isn't it common for a bridged amp to double its distortion, cut its damping factor in half and present half the speaker load to each amp channel? Not that the distortion is gonna be heard or the damping factor will drop so low as to not be able to handle speakers.

 

[J!m]

I think that’s “rule of thumb” but each amp is different.

Counterpoint didn’t quite double down on distortion when bridged but it is already high, so doing things how Mike directed me, Apparent wattage doubles while distortion remains constant.