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
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We finished our last MK2 transformer install yesterday.

Wow... Many flaws. All digital boards standoffs were completely loose. The bolt that holds the power transformer was not even tightened. It was moving around inside the case. The i2s inputs grounding tabs were not contacting the chassis, The ribbon cable to the display was resting on the power transformer, Three adapter boards were used on the SPDIF / AES XLR circuits causing a loud pop when switching from DSD to PCM. We have seen many of these adapter boards in customer units over the past 6 months.

These are just some of the reason we are no longer offering transformers for the MK2. We have found many other issues as well.

If you see these adapter boards in your unit you will have this loud popping issue.

Fortunately our unit we sold a few weeks ago did not have any of these adapter boards.

We are very excited to announce our Signature Series PLUS upgrade.

It includes our Signature Series with a very good internal linear power supply for the analog section. We even isolated the AC lines going to each power supply.

We have been working on finding the very best supply for this application and we feel we nailed it.

We use the complete bottom of the DAC for the heat sink keeping the internal temperature low. We use only the best capacitors and diodes available as well as using a high quality discrete circuit with a MOSFET (attached to the bottom of the unit) to regulate the voltage. The R-core transformer is icing on the cake and is very low noise especially with the thick copper flux band.

Signature Series PLUS

In this configuration we use both the factory Digital and Analog fuse locations.  You can pick your best digital fuse and your best analog fuse.  Digital is 1a analog is 5a.

We could not believe how real percussive instruments and vocals sound now with this supper low impedance power supply powering the important analog stages. We thought the original Signature series sounded better than the new MK2. We feel this new PLUS blows it away.