Sjöström Audio DIY forum

Projects => Headphone amplifiers => Topic started by: ColinS on July 21, 2009, 02:50:37 PM

Title: QRV-07 Power supply stage
Post by: ColinS on July 21, 2009, 02:50:37 PM
Having looked closely at the circuit diagram for the QRV-07 I have a question about the 100nF capacitor which appears to be part of the feedback loop round the regulator ICs (C26/30/34/38).

This appears to reduce feedback at high frequencies which will increase noise/ripple on the output of the regulator. I believe this will worsen the performance of the powersupply.

What is the reasoning behind the inclusion of these capacitors?

ColinS
Title: Re: QRV-07 Power supply stage
Post by: peranders on July 21, 2009, 03:50:54 PM
Those caps are lowering the gain and by that increasing the feedback at high frequencies. This will also increase the ripple rejection. More info about this can be found in the datasheets for the regulators.