PSRR and Crosstalk

I have a couple of questions about the interelationship between PSRR and Crosstalk as is relates to small scale discrete class A design.

I've been working with a couple of different class-a headphone amp designs that have been popularized on the I've started testing them with RightMark Audio Analyzer and the stereo crosstalk figures are not that great (-60 to -75dB range).

The topology is known to have poor PSRR because of the discrete topology. My bench power supply is pretty clean, but not ultra pristine.

Q: Is there a specific relationship between amps with poor PSRR and poor crosstalk figures?

Q: What mitigations are typical to improve crosstalk figures in discrete class-a designs?

Nelson Pass

The one and only
Paid Member
2001-03-29 12:38 am
This is a complicated subject. There is not a general direct
relation between PSRR and crosstalk, but they are often
found together as a result of poor design or workmanship.

Nothing works as well as mono amplifiers and quiet supplies,
but you can build quieter stereo amplifiers by isolating and/or
filtering the supply rails, and you can improve PSRR by
locating those elements which let rail noise into the gain path
and fixing them up. Often this involves the use of high quality
constant current sources.