Tonight I finished an active I/V stage for the TDA1545 DAC. Up until now I have used a resistor I/V for both my TDA1543 and TDA1545 DAC, this has some undesirable effects as the current output of the DAC should be looking into a very low value resistor, and a fairly high valued one is needed to get a deecent voltage output (http://members.chello.nl/~m.heijligers/DAChtml/Analogue/IV.html). Besides presenting a better impedance to the current output of the TDA1545, the active I/V stage also brings the output to about 2Vpp, in it's current configuration. The I/V stage was designed by "rbroer" of diyAudio, the original thread is here: Single rail, active I/V for TDA1543, TDA1545A.

The sound with the active I/V is definitely better. My test setup is a long way away from my stereo, therefore the DAC has to drive a 20 meter long cable, which has always led to a "muffled" sound. Since the active I/V has better current and voltage driving capabilities, this is now gone. This is a wonderful experiences, no magic, simple logic, that manifests itself, in the way I would have expected. Everything is firm and in control. As far as I can see this can only improve things, even when the DAC is back in place, with a half meter of cabling.

I will post a the relevant layout files, when I have finished testing and tweaking.

Generated on 2018-05-03 01:14:21.914522