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Modding the PS Audio Directstream DAC MK1 and MK2

I would like to continue discussing all the mods we have created for these two DAC's as it seems PS Audio is no longer allowing discussions about them on their forum.

For reference here is a link to the closed discussion.

https://forum.psaudio.com/t/modding-the-directstream-dac-mki/2680

128x128richardselectronics
lkdog
417 posts
 

I think you may be able to order the i2s shorting plug for the i2s input #2 which is supposedly the noisier one from Jeff, or post a WTB on the Marketplace at PSAudio and somebody should have one. I guess you can make them also if you know what you are doing.

I have one and also a USB shorting plug. I use the i2s input #1 from a Matrix USB converter which is fed by Lumin U1 mini streamer.

All I can tell you is the noise floor is lower overall with all of the mods which is always a good thing.

It is a cliche, but the music comes out of a black background and sounds live on good recordings. 

lkdog
417 posts
 

I should note I also kind of lucked out and there was a used analog power board module on the PSAudio forum I picked up and installed. Ordered a decent external Chinese LPS to use with it and that also was a nice incremental upgrade for minimal cost.

Really pleased with this DAC.

 

jannik
1 posts
 

Good thing we can continue the discussion here : )

 

I have a long weekend ahead and hope to share some photos of the internal power supply with changes for the supply of the digital part

 

@Jeff: Do you know when the next batch of APS trafos is ready for shipment? Cant wait

jkrichards's avatar
jkrichards
39 posts
 

These MK1’s are hard to beat.

We will also reconsider making another batch of power boards. Our break even number is 5 boards at $300 ea.

This is a plug and play solution that will allow you to use the internal PS or the external one. If no external PS is hooked up the unit will use the internal PS. If the external PS is hooked up then the External PS will be used. It will be automatic and also will pass the power to the analog board at the correct time during power up. This will be a card that slides in the Bridge port with the external power supply connector and LED indicator. All one needs to do is move the analog PS plug to the new board and connect the supplied cable to the analog board. Kit will include the cable with the 2 pin connectors for the external power supply and the DSD.
We make the cables out of 14AWG 2.4mm OD Silver Plated FEP Wire High Purity OFC Copper Cable.

 

DS DAC External Power Controller PCB Top 2021-11-19
 

 

DS DAC External Power Controller PCB Bottom 2021-11-19

 

This is what everyone will receive.

usps1

 

It’s very simple to install.

  1. Remove top cover and Bridge II / Cover. Use a ground wrist strap for static protection.
  2. Slide this DS DAC EXTERNAL POWER CONTROLLER board in the Bridge II slot and fix with the 2 screws.
  3. Remove the power connector from analog board and connect to the DS DAC EXTERNAL POWER CONTROLLER boards [INTERNAL PSU IN] connector.
  4. Use supplied power cable and connect from analog board power connector to the DS DAC EXTERNAL POWER CONTROLLER boards [POWER OUT TO ANALOG BOARD] connector.
    Note: all power connectors are keyed for correct polarity.
  5. Test the unit by powering on the DAC AC switch “without” the external power supply connected. The DAC should work as it did before using the internal power supply. (NO LED) Internal power supply mode.
  6. Power down the unit with the AC switch on the back of the DAC. Connect the external power supply to the DS DAC EXTERNAL POWER CONTROLLER boards external connector and turn on the power supply “only” at this time. The LED on the Power board should light RED (Standby Mode)
  7. Power on the DAC’s AC switch. The LED should turn GREEN indicating you are now powered from the External Power Supply. (Normal External Power Mode).
    *Always turn on the external power supply first or at the same time as the DAC AC power.
    You can leave external power supply on 24/7 as the DS DAC EXTERNAL POWER CONTROLLER board will sequence the external power supply to the analog board at the correct time.

*** AS IN ALL MODIFICATIONS, WE TAKE NO RESPONSIBILITY FOR THIS MOD IF DONE INCORRECTLY OR OTHERWISE. THIS MOD IS DONE SOLELY AT THE OWNERS RISK. THIS WILL VOID ANY WARRANTY.

Thanks!

jkrichards's avatar
jkrichards
39 posts
 
jannik

@Jeff: Do you know when the next batch of APS trafos is ready for shipment? Cant wait

We have one pair available now. More to come in June.

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