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

Quote:

Are there any reviews from someone who upgraded their DSD MkI DAC from the original APS transformers and VOCM  mods to the new Signature series plus?

 

Thought we would post some of the reviews of the Signature Series PLUS.

 

07/07/2024

Allears

We had fun yesterday comparing my Signature Series Plus with my friends modified Directstream.
He had his DAC upgraded last year by APS with the standard VOCM mod, the original APS nickel transformers and some power supply mods. Both units have Snowmass V1 (3.00) firmware installed (The APS recommended firmware)
We started off listening to his DAC. We switched all the cables from mine to his and set the DAC’s volume to 92. It sounded really good although I could hear the deficiencies in comparison to what I was used to hearing however I didn’t say anything. We both listened to his favorite tracks. I picked a couple of my favorites then we switched in my DAC. The first few seconds they sound very similar however after about a minute he looks at me and states I wish mine would sound so real. It was so obvious after a few minutes of play the difference was so big, its chameleon like, mood-lifting performance and energy gains were…so real sounding. You need to hear to believe it how it handles double drums, fast solos, percussive instruments and quick shifts in dynamics. Nothing will slip past its gaze like it knows exactly what it will be playing. With the Signature Series Plus, expect an unlimited well of explosive dynamics and that’s how we both felt it was with every musical genre. It was rich sounding, full-bodied, but also very defined, preserving sharp leading edges. You could hear the room it was recorded in so clearly. Detail retrieval or transparency are redundant with a unit like this, as it will playback every single bit of information with utmost accuracy and in a very life-like manner. It doesn’t sound like digital, it sounds like music played back in real time, by real musicians sitting in front of you, playing just for you. When it comes to resolution and dynamic range, My DAC single handedly outperformed his DAC.
Don’t get me wrong his DAC sounded wonderful just not as good as the Signature Series Plus.
Before he left last night my friend ordered the Signature Series Plus upgrade at the VIP price and never looked back.

 

7/19/2024  Signature Series PLUS upgrade.

Received my DAC back last Tuesday.  After three days of listening,  all I can say is "Wow, that is A LOT OF DETAIL!!" Imaging improved, and bass seems to be significantly extended without sounding bloated.  I had to reduce the volume on my subwoofer. 

Needless to say,  I'm very satisfied and impressed with this upgrade. Thanks for the great job and the fast turn around. 

Keith C.

 

Talked to my buddy last night He received his Signature Series Plus upgrade yesterday. That was super fast turnaround by APS. He sent it out on Monday and received it back on Saturday. He is thrilled with the sound and quality of the upgrade. He thought the new badging on the front is a nice touch.
 

Post removed 

We have some exciting news. We have been working on a new Directstream DAC upgrade for the past six months and have finally released it.

Our new Limited Edition Signature Series PLUS DAC.

The Limited Edition is the latest model in a series of the finest and most successful DAC upgrades ever made. Providing even more presence, weight and definition than that of its predecessor, the Signature Series PLUS.

The Limited Edition clearly redefines the state of the art at a price that is not inexpensive but represents extraordinary value.

While differences in recordings are immediately apparent, the Limited Edition connects you to the intent of the musicians and the soul of the performance, drawing you in even more.

This unit extracts the room ambience like no other. You can clearly hear the room where the original recording was produced.

Only by hearing it for yourself will you fully appreciate the sonic advancements unveiled by the Limited Edition.

The Limited Edition possesses great bandwidth and resolving power combined with a purity and naturalness that is uncanny – grain and electronic artifacts are simply absent. Bass impact, depth and control is startling, while music ebbs and flows with a dynamic life that is rarely experienced outside the concert hall.

 

This upgrade includes the following upgrades in addition to our Signature Series PLUS upgrade:

1- Our New pure copper IEC AC input socket.

2- Silver AC input wiring.

3- A 50% larger pre-regulator capacitor.

4- Our discrete 5 Volt regulator for the digital input board.

5- Additional post regulator capacitor.

6- Hand-picked Rev.2 transformers.

 

Our new pure copper IEC AC input connector.

New capacitors we use.

Our new 5v discrete regulator for the digital input board.

 

https://www.youtube.com/watch?v=iFmOhR0zp2Q&t=1

 

Is there an OP amp in the DSD DAC? If so this OP amp Danny is talking about sounds like it would be worth upgrading to.

The opamps in this Directstream DAC are special high frequency video opamps. The ones Danny is speaking of from Sparkos is a replacement for standard opamps (not compatible at all with the DS). We make our own discrete opamps for other equipment.

We have tested other compatible opamps however the ones in the DS work the best especially when the DC offset is fixed. We have spent 1.000’s of hours working with the Directstream MK1 DAC and feel it’s at it’s best with the Limited Edition upgrade. We even tried using a custom opamp output stage instead of our transformers and it didn’t sound even close to what have now. Ted designed these DS DAC’s to use an audio transformer for a reason.