Do you use standard filter pack?
Is you PCM stream correct (not larger than 24bit 192k)?
The firmware is done to support the 2nd i2s port, including autodetect, just need some more testing and cleanup before release...
Can't really be a hardware issue. Have you changed settings in uManager ? What channel does it output ?
And no, it measures 30 ohm between each output and gnd, the mute jfets are about 30 ohms when muting. If you need to check output impedance, do it while powered on, but without music playing.
And no, it measures 30 ohm between each output and gnd, the mute jfets are about 30 ohms when muting. If you need to check output impedance, do it while powered on, but without music playing.
Well, as it outputs mono, a short between the channels was suspected - hence the idea to measure the resistance between the channels rather than against ground.
If it outputs combined L+R mono or one channel mono must be verified.
An out-of-phase signal (CD phase test) becomes silent.
On the 1921, what command/setting can produce mono?
Manual says:
set par=value set paramter to value, set alone to show
conspeed = 9600 | 19200 | 38400 | 57600 | 115200
volume = fixed -80 - +10, line output startup volume
filter = linear | mixed | minimum | soft
mode = normal | parallel
//
If it outputs combined L+R mono or one channel mono must be verified.
An out-of-phase signal (CD phase test) becomes silent.
On the 1921, what command/setting can produce mono?
Manual says:
set par=value set paramter to value, set alone to show
conspeed = 9600 | 19200 | 38400 | 57600 | 115200
volume = fixed -80 - +10, line output startup volume
filter = linear | mixed | minimum | soft
mode = normal | parallel
//
Last edited:
It was loaded with this filter:
+ a few biquads not showing here.
dam1021,44100,8,4,1999,8
04 TNT441Lin Linear Phase FIR1, 44.1 Ksps, 0-19,4 Khz - 0.3 db, 22.04 Khz -163db
0.0000000000199589610540556
0.0000000000183149373464365
0.000000000014025867195505
0.00000000000762654397771003
-0.0000000000000419597726246247
-0.00000000000793830876143231
-0.0000000000149570322334715
-0.0000000000200777552540517
.....
//
+ a few biquads not showing here.
dam1021,44100,8,4,1999,8
04 TNT441Lin Linear Phase FIR1, 44.1 Ksps, 0-19,4 Khz - 0.3 db, 22.04 Khz -163db
0.0000000000199589610540556
0.0000000000183149373464365
0.000000000014025867195505
0.00000000000762654397771003
-0.0000000000000419597726246247
-0.00000000000793830876143231
-0.0000000000149570322334715
-0.0000000000200777552540517
.....
//
Attachments
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No crossfeed is a function added in dac1421/dac1541, and the dam1941 is based on the dac1541 so it support crossfeed.
For those who don't know crossfeed, it's a function to be used with headphones to reduce the with of the soundstage to simulate speakers. The dac1541/dam1941 do it using digital filters that mixed the two channels.
Try google if you need more info.
Correct, the first 8 biquads is reserved for the crossfeed so there is only 7 left for the user. I didn't expect that to be a problem, but if needed I can add a software switch to disable to crossfeed function.
The filter file is on the website, new firmware will come up very soon.
For those who don't know crossfeed, it's a function to be used with headphones to reduce the with of the soundstage to simulate speakers. The dac1541/dam1941 do it using digital filters that mixed the two channels.
Try google if you need more info.
Correct, the first 8 biquads is reserved for the crossfeed so there is only 7 left for the user. I didn't expect that to be a problem, but if needed I can add a software switch to disable to crossfeed function.
The filter file is on the website, new firmware will come up very soon.