[SOLVED] Kali & Piano 2.1 channel imbalance in dual mono mode.

[DRONE7]

Finally had some spare time to test and troubleshoot this .....

Tim,  in the Chip/Device Options when Analog gain is set to -6dB this is applied to only one(Main) of the 2 dac chips .

Consequently if Dual mono is selected the left channel (Main dac) is -6dB down vs the right channel ("sub-woofer" dac)

In order to operate my amp in it's 'sweet spot' (and prevent huge volume shocks  when changing input sources !) I need the -6dB set for both dacs to be able to use Dual mono...
Could this be a moOde settable value ? or is it part of the Kali/Piano 2.1 firmware package ?

(I have a question in with Allo on this )

Thanks,
Bob

[Tim Curtis]

Hi Bob,

Its prolly a driver issue. moOde just sets the ALSA values below. They also appear in Alsamixer.

Analogue
Analogue Playback Boost
DSP Program

[DRONE7]

I can re-balance using the alsa L/R volume settings but can't make it stick over reboots.

Code:

sudo alsactl store

Doesn't save nor does appending the card number from

Code:

aplay -l

so this doesn't work either.

Code:

sudo alsactl store 1

Any pointer to save alsa settings ??

Also found the filter setting seems to be for the first Dac only too  but that can be worked round by resampling to 32/384 and bypassing the filter for both Dacs.

Allo seem to have a flexible notion of time...   their "we will reply to your enquiry within 48 hours" has stretched to 96 hours and counting..lol

[DRONE7]

Well, having parked the Allo kit (Kali and piano 2.1) for some time (as the infuriating 6db imbalance drove me nuts...) I used some lockdown time to try again to set it correctly..... Previously no matter what I set it was overwritten randomly so the sub volume would one boot be 100% and another 81%....using dual mono meant there was always one channel maddeningly wrong!!

I am now pleased to have equal volume levels in both channels using dual mono after several restarts...  

Here is what worked...
Install the Allo DSP files (note, we will not be configuring the sub-woofer options...just installing the firmware that then allows the sub-woofer dac chip to have the volume setting saved for use with dual mono mode !! )

Code:

cd ~
wget https://github.com/allocom/piano-firmware/archive/master.zip
sudo unzip master.zip
sudo rm ./master.zip
sudo cp -r ./piano-firmware-master/lib/firmware/allo /lib/firmware
sudo rm -rf ./piano-firmware-master

 I have set  MoOde MPD  Config tab >Volume control=disabled
and in Audio Config >ALSA max volume =94
then in Audio Config > Edit Chip/Device  Options
and set Analogue gain =0db
and Subwoofer volume =94

Restarted and from

Code:

./piano.sh

it returns..
Dual mode: Dual-Mono
Subw mode: None
Sub xover: 60
Sub level: 94%
Main levl: 94%
Mstr levl: 94%

so now both DAC chips output the same volume !!!