DAC Mute on for high bitrate files

[Tranquility Bass]

Hi Dave

Can you send me that table. I assume it is in Excel.

I think I know what's going on.

Regards
David

[dch53]

Here you go.

[Tranquility Bass]

OK I have added another column for the codes in binary and you can see that the third bit is always stuck high so the DSD modes get translated into unsupported modes where the software will always mute the preamp. Other modes will be translated as well not giving the right indications on the front display.

You may have to disassemble the Amanero/isolator board (screwed from the bottom of the chassis ) and first check the connections between that and the isolator board. If you PM me your email address I will send you the schematic of that board so you can trace the connections (look at F2 on the Amanero side and DIO10 on the DSP side). Because I hand solder the IDC connectors there can sometimes be a residual bit of flux that can may affect the connections if it hasn't been cleaned off. You may need to spray the connectors with some contact cleaner or I like to use CRC-226. Alternatively the Amanero board maybe flaky but check the solder joints on the IDC headers on both boards. Also it is possible that it is stuck high on the DSP board but first check on the Amanero side.

regards
david





 

[dch53]

Thanks to David for giving me debugging directions. Problem is probably a dodgy connection of pin 112 of the DSP chip to the main PCB. Prodding the pin with a very fine probe seems to have fixed it for now.

I use a company in Perth to solder very large surface mount ICs for me when I have projects that require them. If the problem recurs I'll take my UP to them and get them to resolder that joint.

[Tranquility Bass]

Thanks to David for giving me debugging directions. Problem is probably a dodgy connection of pin 112 of the DSP chip to the main PCB. Prodding the pin with a very fine probe seems to have fixed it for now.

I use a company in Perth to solder very large surface mount ICs for me when I have projects that require them. If the problem recurs I'll take my UP to them and get them to resolder that joint.

Hi Dave

If you have access to a high mag viewer check the relevant pins of the QFP chip to check that the leg is not floating above the pad by wiggling it a bit with a very fine dentist pick. I usually reflow these pins with a hockey stick type iron tip and some flux.

regards
david

[dch53]

Thanks David. If the problem recurs I'll do that. I'll see if I can get a hockey-stick bit for my soldering iron.