[b0bb]

Thank you for the response, @b0bb !
My DAC still doesn't put out any sound and the voltages on I/V resistors are read between 0.082 and 0.096 volts while playing the test audio files.

Is your DAC able to playback normal audio files?

The test file is a 10s 1kHz sinewave sampled at 44.kHz, try playing it back on something other than the DAC using the same audioplayer

 

[leondikim]

I appreciate your reply! No sound comes out from any other audio files nor from the web browser.. but on computer the sound is coming out on the monitor (you can see the volume meter is moving). Changing the sampling rates doesn’t help either. Even the correct sampling rate is shown on the 004 status screen.

 

[b0bb]

Part of the analog section is not working, probe the pins for the analog supply and check they are at the correct voltage.
There several pins, check all of them.

1. 1.2V (VDD_L and VDD_R)
2. 3.3V (AVCC_L and AVCC_R)

Start with VDD, the regulator on some versions is undersized and not cooled adequately, start there.

 

[leondikim]

Thanks a lot! May I ask you which analog supply I should begin with? Voltage supply?

 

[b0bb]

Start with the pins on the dac chip itself.

 

[b0bb]

VDD pins are at the corners of the chip, relatively easy access, use a needlepoint probe.
This is the standard probe on most multimeters.

Take it slow, do not short the pins adjacent to the corner with your probe, the pins adjacent are ground.
A short will damage the chip.

Some of the AVCC pins are also at the corners

 

[leondikim]

Okay! Thank you for the kind instruction! I don't want to damage the chip. I will post the result tomorrow afternoon.

 

[wersuss]

Hello, i have problem with this dac again , somewhere is short circuit maybe ve + on xlr shows 1.568 volts that's minimum i can set with trim pot. The voltage regulator the middle one gets very hot 90c and first from left 80c. The last from left stays coldest at 40c. Is it possible to find problem?

 

[b0bb]

Hello, i have problem with this dac again , somewhere is short circuit maybe ve + on xlr shows 1.568 volts that's minimum i can set with trim pot. The voltage regulator the middle one gets very hot 90c and first from left 80c. The last from left stays coldest at 40c. Is it possible to find problem

Replied to your private message.

 

[szrurs03]

Here is one way to increase the microdetail and soundstage of the 004.

The 2 pale green resistors with 1904 written on them are 5ohm Vishay VSMP Z-Foil
- Non inductive
- Non capacitive

Makes the near perfect candidate for the coupling resistors connecting the XO to the pair of 9038PROs

dear b0bb
Can you share the mouse link please?

 

[b0bb]

dear b0bb
Can you share the mouse link please?

https://www.mouser.com/ProductDetai...s/Y16285R00000D0W?qs=PQqCikkAB6UJ3wDE6ApbTQ==

The price doubled in the last 18months, consider upgrading the XO if you have not done so, a pair of the resistors costs more than the Crystek CCHD950X XO

 

[szrurs03]

https://www.mouser.com/ProductDetail/Vishay-Precision-Group-Foil-Resistors/Y16285R00000D0W?qs=PQqCikkAB6UJ3wDE6ApbTQ==

The price doubled in the last 18months, consider upgrading the XO if you have not done so, a pair of the resistors costs more than the Crystek CCHD950X XO

I use Newclass d neutron star 2 as a clock

 

[szrurs03]

I use Newclass d neutron star 2 as a clock

Have you tried other upgrades recently?

 

[b0bb]

Have you tried other upgrades recently?

The last upgrade I did to the 004 was to widen the bandwidth of the I/V. DSD512 maxes out at just under 25MHz.
The I/V output transistors on my DAC have a transition frequency (fT) of 50MHz, I replaced them with 150MHz devices.
The higher speed also meant a lot of work to stabilize the DAC, the mod took a few hours, spent the rest of the month tweaking and stabilizing.

The work I did on the 004 also meant that it started to expose the limitations of other items of the chain like the DDC and audio endpoint
The work on the DDC is in the SU2 and SU6 threads.

My latest endpoint is the Fitlet3, dual core atom x6000.
Intel's latest 10nm Elkhart 6W core.Fully passive.
Real time kernel for the lowest latency
Fiber optic ethernet, intel NIC, goes directly to the fiber backbone, 2 hops to the server.

Total power is 6.6W with the fiber NIC active

This is a step up from the CoffeeLake NUC8 I was using.

 

[szrurs03]

The last upgrade I did to the 004 was to widen the bandwidth of the I/V. DSD512 maxes out at just under 25MHz.
The I/V output transistors on my DAC have a transition frequency (fT) of 50MHz, I replaced them with 150MHz devices.
The higher speed also meant a lot of work to stabilize the DAC, the mod took a few hours, spent the rest of the month tweaking and stabilizing.

The work I did on the 004 also meant that it started to expose the limitations of other items of the chain like the DDC and audio endpoint
The work on the DDC is in the SU2 and SU6 threads.

My latest endpoint is the Fitlet3, dual core atom x6000.
Intel's latest 10nm Elkhart 6W core.Fully passive.
Real time kernel for the lowest latency
Fiber optic ethernet, intel NIC, goes directly to the fiber backbone, 2 hops to the server.

Total power is 6.6W with the fiber NIC active

This is a step up from the CoffeeLake NUC8 I was using.