68.221.12.142
In Reply to: RE: best lundahl to use with pcm63 and tda1541a posted by AlexanderKonyarov@yahoo.com on June 02, 2009 at 06:47:04
With DAC chips like the PCM63 that have a unipolar current output and bipolar power supplies, and have, therefore, no DC bias on the current output, you can use pretty much any transformer that fits your need for output voltage level. I prefer the sound of the cobalt amorphous strip core transformers like the LL1636 and LL1674.
With either voltage or current output DACs with differential output stages and unipolar power supplies, you have to take care to exclude the flow of DC "offset" current through these transformer's primary windings unless the windings are symmetrical and the magnetic field resulting from current flow can be canceled by counter-directional flow.
For differential voltage output DACs, you probably don't need more than a 1:1 transformer, such as the LL1544A or the LL1690. I don't have much design experience with voltage output DACs (we prefer current output DACs), but the issue of current flow in the primary is the issue if you are to avoid coupling capacitors.
Kevin Carter
K&K Audio
www.kandkaudio.com
Follow Ups:
Post a Followup:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2009, Audio Asylum, all rights reserved ]
[ Go Green ]
[ Take5 ]