• These commercial threads are for private transactions. diyAudio.com provides these forums for the convenience of our members, but makes no warranty nor assumes any responsibility. We do not vet any members, use of this facility is at your own risk. Customers can post any issues in those threads as long as it is done in a civil manner. All diyAudio rules about conduct apply and will be enforced.

Reference DAC Module - Discrete R-2R Sign Magnitude 24 bit 384 KHz

TNT

Member
Joined 2003
Paid Member
How does smaller adjustment steps help? I mean your problem as I understand it is the actual deviation in frequency - if you get to a bad situation (bigger delta Hz), does it matter in how many steps it took to bring it there?

For clock quality in general, smaller but more often clock changes I cant see how this could be an improvement..

//
 
I used an old AVID case for it. Put the active cooling back with the fans running at a very low voltage. 16 DAM1021 together in a case do produce some warmth. :)

16 channels... oh wow. Is that for DIY or (semi-) professional use? What are you driving / is its intended purpose?

I still don't understand how the output op amps in the DAM1021 are powered. It appears the voltage is always only slightly below the incoming DC voltage. That would be fine with a quality PSU powering the DAM, but how can there be clean DC with AC input only?

I'm not sure I understand your question. According to the manual there's a full wave rectifier bridge for AC/DC conversion. It increases voltage by sqrt(2) minus a couple of volts for the rectifier loss. Then I assume it is regulated down by dropping voltage over LDO's.

Most mods on the dam1021 concern the Vref. Myself I would prefer an external PSU so I can pick the amount of regulator noise and buffer capacitance myself, one of the reasons I went with the dam1121.
 
For those who cannot be bothered to right click :)
 

Attachments

  • 3DoR3NOr.jpg
    3DoR3NOr.jpg
    1 MB · Views: 295
How does smaller adjustment steps help? I mean your problem as I understand it is the actual deviation in frequency - if you get to a bad situation (bigger delta Hz), does it matter in how many steps it took to bring it there?

For clock quality in general, smaller but more often clock changes I cant see how this could be an improvement..

//

I want both, the SQ and the deviation problem to be solved. Both can be solved, I think, as the incoming clock is steady when measured over a longer period of time and when adjustments are made more infrequent and finer.
 
16 channels... oh wow. Is that for DIY or (semi-) professional use? What are you driving / is its intended purpose?

It is primarily for use with a large format studio mixing console.

I'm not sure I understand your question. According to the manual there's a full wave rectifier bridge for AC/DC conversion. It increases voltage by sqrt(2) minus a couple of volts for the rectifier loss. Then I assume it is regulated down by dropping voltage over LDO's.

The linear regulators I have used all have a frequency that is either fixed or can be set by a simple surrounding circuit. What is on the DAM1021 appears to drop the voltage to a level in relation to the incoming voltage.

Most mods on the dam1021 concern the Vref. Myself I would prefer an external PSU so I can pick the amount of regulator noise and buffer capacitance myself, one of the reasons I went with the dam1121.

The VREF didn't improve when I added capacitance (tried several cap types and configurations). What did provide a very noticeable improvement was additional capacitance after the the 3.3V regulator.
 
Just a resistor or voltage divider then? Which should be fine if placed after the power regulation circuit, I mean, that would give a more or less constant VDC so also a constant voltage drop. Or are you saying it seems to bypass the power regulator?

It gives a constant voltage drop, but not to a defined level but dependant on the incoming voltage.
 
Or are you saying it seems to bypass the power regulator?


You guys are not the only pathologically lazy ones. I also cannot be bothered to take a continuity tester to the dac :D

Never wondered how those opamps are powered but in my defense they were the first parts to leave the board with one way tickets.

Looking at pics of the pcb it looks like there is indeed no regulation: raw dc seems to be powering those parts. No biggie.
 
Hooked up a Kali reclocker tonight. As I ordered the board last week, I was very much in doubt if that was money well spent. After all, with the FIFO-buffer slaved to the Si570 on the dam1121, could this even be audible? Was I buying into audiophoolishness?

Turns out it *is* audible and amazingly so. I wasn't expecting much and took a critical stance. But the retrieval of extra detail is immediately obvious. It makes saxophones sound more fragile, distorted guitars grittier, percussion more natural.

Stack now is RPi 3B+ > IsolatorPiII > Kali > dam1121. The RPi is fed off one DIYINHK LT3045 board; the IsolatorPiII, Kali and dam1121 digital from a separate LT3045 board that they share for "clean audio power".

In other attempts to reduce RPi jitter, I had set the RPi CPU scaling governor to "performance" and CPU and RAM frequencies to be multiples of each other like so: Archimago's Musings: MEASUREMENTS: Raspberry Pi 3 as USB Audio Streamer (with recommended CRAAP config & TIDAL/MQA arrives). This is now no longer necessary. Back to the on demand governor again without the frequency tweaks. My RPi now runs cooler while drawing less power.

In an attempt to match the 19,2 MHz clock on the RPi, also tried upsampling 44,1 to 48 kHz on the RPi using the ALSA speedrate_best plugin, but thought it sounded ever so slightly thinner with a slight metallic ring to it.

TL;DR an external reclocker in front of the dam significantly improves the sound.
 
Hi Sören,

I am at a loss, sorry if this is the wrong thread...

I would like to buy a DAC2541 but don't know how else to contact you.

Hope you can at least reserve one of your famed converters for me, be they in stock now or in the near future ;)

Cheers

No, this is not the correct place for end-user products.... Please send an email to info@soekris.dk, if you already done that, please just email again.