REVISIT#2 - DIY TDA1541A DAC

Recently retrieved the unit (REF: http://myoldvintagehifi.blogspot.com/2018/04/revisit-diy-tda1541a-dac-with-usb.html) from storage for a listen, only to discover that it did not sound as clear nor as precise as my Meridian 600-series DAC. I do not expect it to best the Meridian but the reproduction was clearly "more muddle" than it could have been.

Hence I Google-d for TDA1541A DAC schematics and upon review, discovered the capacitor values deployed in the output stage (where the opamp are) can vary drastically, depending on implementation - section encircled by yellow line in the pix below.

Output section with op-amps

Cross checking the Google-d information for the capaciitors deployed in the op-amp section, vs,  the values etched onto the op-amp section of  the PCB, these values differ drastically. And examining the capacitor themselves, again result in different values than the etched values on the PCB next to the capacitor itself!😒 Well, what can I say - I did buy it from a China based eBay seller....

For the record, all the blue capacitors deployed in that section are Vishay 1nF 100V. 

After some basic tracing of the PCB connectivity, I decided to try replacing the encircled capacitors in the pix below with Wima 100pf 100V.

1st Capacitor to be changed in op-amp section

Opon power-up, output clearity and realism (being less muddle-d) has been drastically improved ... will update after I have an opportunity to "run-in" the change.