60db and 90db is just estimation, because I didnt mesure it. It is so low that I have to set maximum volume on my amplifier but still cannot hear normally.
If I2S signal cannot cause this issue, then I can ignore the SDTrans384.
Regarding filter, I still use stock filter, never upgraded.
How about PWR voltage input? I feed 6.4VDC to Soekris, but it was operating normally for a longtime before.
I noticed onetime output level is suddenly came up, but for few second only and then became very low. It might be a stability issue, but I do not know where to check.
If I2S signal cannot cause this issue, then I can ignore the SDTrans384.
Regarding filter, I still use stock filter, never upgraded.
How about PWR voltage input? I feed 6.4VDC to Soekris, but it was operating normally for a longtime before.
I noticed onetime output level is suddenly came up, but for few second only and then became very low. It might be a stability issue, but I do not know where to check.
+-6.4V DC is below specs, mute circuit might be operating just at the limit....
Check the control signals to the mute fets, measure the voltage on the center pin, the one going away from the resistors networks, on the sot23 fets next to J7.
And connect the serial cable and check the volume.
And measure the vref voltages directly on the shift registers.
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Vref voltages is 4VDC, are Mute fets Q3 and Q4 next to J7? I could not measure voltage on its center pins, it is almost 0V or sometime fluctuate around 0.3V. But voltage at capacitor next to it is 9.5V.
I will try finding a serial cable to check volume, never connected it to my computer before.
Thanks Soren
I will try finding a serial cable to check volume, never connected it to my computer before.
Thanks Soren
The mute jfets are Q3 & Q4. I have no idea what capacitor you're referring to.
If center pin on the jfets are 0V, or close to, then the fets are ON and will mute the signal. Are you sure you're feeding the dam1021 min 7V ? Try measure the PWR- on pin9 on J2.
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Hi Soren,
Those capacitors I mentioned are marked as in the picture below.
I am feeding the DAM by +-9.88VDC and PWR- at J2 is -9.54V.
Suddenly today when I turn on DAC to measure voltage again, voltage at center pin of Q3,Q4 is +-9V, and I got normal output level again.
Not sure this issue comes again, in the worst case, can I remove Q3,Q4 to get normal sound?
Thank you.
Those capacitors I mentioned are marked as in the picture below.
I am feeding the DAM by +-9.88VDC and PWR- at J2 is -9.54V.
Suddenly today when I turn on DAC to measure voltage again, voltage at center pin of Q3,Q4 is +-9V, and I got normal output level again.
Not sure this issue comes again, in the worst case, can I remove Q3,Q4 to get normal sound?
Thank you.
Attachments
Eeeh, do you measure +9V or -9V ?? the jfets are on (audio muted) when there is 0V, and off when there is -9V....
I don't recommend that, as you instead will get large thumb at power on/off....
You really need to figure out what the problem was. Maybe you had a bad connection somewhere....
I didn't notice it is + or - 9V. But I got normal output level.
Unfortunately, after few hours listening at normal output level, issue is back while I am listening. Got 0V at Q3,Q4 center pins.
Is there other thing that controls this voltage, or it is quality of Q3, Q4 itself. I lost sound output level on both channel at the same time.
Unfortunately, after few hours listening at normal output level, issue is back while I am listening. Got 0V at Q3,Q4 center pins.
Is there other thing that controls this voltage, or it is quality of Q3, Q4 itself. I lost sound output level on both channel at the same time.
I suddenly have problems with DSD playback, I do not remember to have changed anything in the setup and before DSD played fine.
PCM playback is still fine. Data is coming via USB and an Amanero, FW 1.06.
Now, when I play DSD I get only a slight noise and in the terminal it displays L176 as "sample rate". So it seams the DSD data is processed as PCM.
To be on the save side I reinstalled 1021full_106.skr (so with the DSD filters - I hope). No changes
Any ideas?
PCM playback is still fine. Data is coming via USB and an Amanero, FW 1.06.
Now, when I play DSD I get only a slight noise and in the terminal it displays L176 as "sample rate". So it seams the DSD data is processed as PCM.
To be on the save side I reinstalled 1021full_106.skr (so with the DSD filters - I hope). No changes
Any ideas?
Latest updates:
Updated muting circuit/relays with 5 second power-on delay & bistable latching relays for headphone amp/xlr output switching. This means no longer is the headphone amp sharing the xlr outputs, an upgrade that was a long time on my todo list. Haven't yet decided on how to do the latching control circuit but am thinking something very simple with 2 pushbuttons/transistors if Audiozen keeps ignoring firmware requests for some extra remote control hooks/outputs.
Remove 15/15/9/9 30va r-core, install 6v/6v 15va donuts/toroids to replace the r-core and az-lite 6va transformers. The original transformer that came with the Audiozen az-lite was a 110/110 unit, at the line voltage of 125V the small core was certainly oversaturating, creating a massive magnetic field and becoming rather warm as a result. A recommended upgrade for anyone with the same issue from the audiozen supplied part. This was mentioned before in another thread by another member, you know who you are, thanks.
Not yet installed: 15v/15v 15va for the headphone amplifier & 15v/15v psu.
Updated muting circuit/relays with 5 second power-on delay & bistable latching relays for headphone amp/xlr output switching. This means no longer is the headphone amp sharing the xlr outputs, an upgrade that was a long time on my todo list. Haven't yet decided on how to do the latching control circuit but am thinking something very simple with 2 pushbuttons/transistors if Audiozen keeps ignoring firmware requests for some extra remote control hooks/outputs.
Remove 15/15/9/9 30va r-core, install 6v/6v 15va donuts/toroids to replace the r-core and az-lite 6va transformers. The original transformer that came with the Audiozen az-lite was a 110/110 unit, at the line voltage of 125V the small core was certainly oversaturating, creating a massive magnetic field and becoming rather warm as a result. A recommended upgrade for anyone with the same issue from the audiozen supplied part. This was mentioned before in another thread by another member, you know who you are, thanks.
Not yet installed: 15v/15v 15va for the headphone amplifier & 15v/15v psu.
Attachments
Meanwhile the 1021filt_105.txt at soekris.dk downloads has changed and includes die DSD filters. But no DSD playback with those either .... so probably the filter is not the cause of my problem.
By the way, the MKROM output of the "current" 1021filt_105.txt is different from the 1021filt_105.skr that came with the 1.05 firmware.
By the way, the MKROM output of the "current" 1021filt_105.txt is different from the 1021filt_105.skr that came with the 1.05 firmware.
Speaking of the content of the filt.txt files...
The "current" 1021filt_099.txt at soekris.dk is:
which only contains filters in the new format (04 etc), but the 0.99 firmware needs the old format.
The "current" 1021filt_099.txt at soekris.dk is:
Code:
-- Format:
-- signature, samplerate, interpolationrate, type, numbercoefficients, multiplier
-- type 1 = FIR1, 2 = FIR2, 16..30 = IIR, 30 = Deemphasis
-- type 4..7 = FIR1 new format, add 1000 for shared filters
-- type 8..11 = FIR2 new format, add 1000 for shared filters
--
-- IIR Coefficients is b0, b1, b2, a1, a2. a0 is assumed to be 1.0000
--
-- FIR1 filters for 44.1K/48K Samplerate
dam1021,44100,8,4,1975,7.8
04 Linear Phase FIR1, 44.1 Ksps, 0-19.7 Khz - 1 db, 22.3 Khz -150db
0
-0.0000000000031857274815944411
...which only contains filters in the new format (04 etc), but the 0.99 firmware needs the old format.