driving two class D buffers with same source.

[montreal]

Hello,

The final stage of my Sony SACD player uses an opamp chip to convert balanced PWM arriving from its internal digital processor into an unbalanced analog signal for delivery to downstream equipment. I want to bypass this Sony opamp chip (BA4558) with a new one (AD8066).

In a seperate project, I want to bypass the analog power amp pre-driver (UPC8521) of my Sony AV receiver to create full 5.1 preouts using other AD8066 chips.

I don't want to remove or alter any of the original electronics in either machine, simply tap into the existing audio signals and route copies of these signals to new circuit boards which duplicate the functions.

In the Sony SACD player, I want to bypass their final opamp filter/buffer, having a balanced input impedance of about 5k. My new circuit will likewise duplicate the current balanced class D PWM low pass filter/buffer function.

In the Sony AV receiver, I want to bypass their final pre-driver chip which has an unbalanced input impedance of 68k.

In both these two machines, we have upstream low impedance circuits driving downstream higher impedance circuits.

If I am to piggy-back my new circuits close by the original ones by tapping into the original signal path without cutting out the original Sony circuits, then I am wondering if the halving of the load, 68k. becoming 34k. in the AV receiver, and 5k. becoming 2.5k in the SACD player, will this result in a loss of sound quality?

All my life, I have never had any problem driving multiple high impedance loads from the same low impedance source. Would doing so in my SACD player and AV receiver be any different?

Thanks for any comments.