The Mk II has an externally accessible fuse. I believe PS Audio is doing that with all future products. PS Audio picked the RCA connectors, they too agree that the current DS’s RCA’s leave something to be desired. I don’t know what they picked, I just cared that they were better and I cared about how they mount on the PCB. 
3 Likes
Another satisfied customer of @wctaudio on the Edcor transformer swap. The sound of the DAC is remarkably better on the first startup. It’s hard to believe that this mod is such a big improvement in an already world class device. Service, price and turnaround time are all top of the heap.
7 Likes
Has anyone done the Edcor upgrade after having installed Sunlight? If so, what difference/improvements have you heard?
Another LPS option: Keces P3.
DS analog board powered by Keces P3 with good results.
After Sunlight, it expands even further the soundstage, the information retrieval and tiny nuances in the music are even more evident.
A single Keces P3 is serving Matrix (7v) and DS analog board (12v).
A second (old) one is serving Bonn N8 network switch (5v) and Custom Roon server (12v).
Ted, will there be a shield between the digital and analog board on the DS MK II? You’ve already explained the AC shield on the board. However, can you further expound on the extent of the shielding for the MK II. Thanks.
The same shielding is used everywhere: a “box” made of flooding of ground on all layers and via stitching on the edges. The bottom of the board is unbroken except for vias (no routing.) The top of the board has essentially only breakout traces or very short point to point wiring where vias would imply too much inductance (e.g. from a bypass cap to the power pin of a component.) The line level AC is treated a little differently, it’s on the outside of the shielding “box” and isn’t flooded with ground, but instead with a separate insulated ground to keep AC shorts from becoming a problem.
Here are the I2S islands each with their own “shield boxes.”
3 Likes
The HDMI connector used for I2S supplies 5V to power small external devices (or interfaces.) The I2S signal receivers and digital isolators use 3.3V. The I2S islands are powered via a 5V isolated supply and on the island some of that 5V is regulated to the 3.3V needed for most chips there.
I2S is the protocol from the I2S connectors to the FPGA ( 
) and from USB to the FPGA. (The Bridge on the DS also connected to the FPGA with I2S.) “Processing inside the Mk II” isn’t protocol related unless you take PCM or DSD as a protocol.
1 Like
Not all digital isolation is created equal. Digital isolator chips were designed for industrial environments where noise is ubiquitous and a little extra noise from the digital isolator is, well, hidden in the noise. Most digital isolators use a high frequency oscillator and turn it on and off to transmit the bits across the physical isolator. Little radio transmitters aren’t what we need in a DAC. There are many choices out there, but I’m not convinced that most audio equipment designers are really checking the RF radiation…
3 Likes
For those who went with the Edcor output transformers. How long did it take for them to arrive after ordering? Thank you
There are many choices available, thank goodness high end audio isn’t the only one that requires very quiet parts.
2 Likes
@paul172… I ordered from Edcor USA and took only 1.5 weeks (ordered late April).
Ok. Thanks for the info. I ordered 5/5 still waiting for shipping confirmation. May get one soon unless there is a run on the Edcor 4400’s!
Hello everybody including me 
Long thread for a newcomer.
I’m unable to upgrade my DAC. My house would definitely be on fire.
A few months ago, I saw a site where they offered different levels of upgrade.
Who could help me by pointing out awesome artisans who could upgrade my Direcstream Dac?
Thank you so much
1 Like
Welcome Jack,
I’m not a DSD expert but I guess the question is what are you referring to as far as an upgrade and what direct stream Dac do you currently own?
Paul
The perfetwave Direcstream DAC.
An upgrade is modification of my unit (clocks as an example) to get it sound the better way it can.
A last a site offered a 4 levels upgrade of the PS Audio perfetwave Direcstream DAC.
If you haven’t already read the second post in this thread, please do:
Basically, if a site offers to upgrade ANY of the things I list in that post that the DS doesn’t have, I’d stay away from them. I’m very skeptical about four levels of well designed upgrades for the DS.
There are others threads with more details. Search for items in a potential upgrade. There might be a post with more info about it (pro or con.)
5 Likes
Now that’s right from the DSD master himself! 
I ordered some Edcor 4400’s to replace the output transformers on my DSD.
1 Like
@tedsmith I browsed a thread and, unless I’m wrong, @Paul ackowledged that upgrading with Edcor XS4400 transformers would improve the sound. It seems that the clock with two can be replaced with better ones : one Premium low jitter clock (44.1, 88.2 & 176.4Khz processing) and one Premium low jitter clock (48, 96 & 192 Khz processing)
That seems to be a two level upgrade.
I suggested the XS4400, the DS was designed to accommodate it. There aren’t two crystals in the DS. If someone is talking about replacing two oscillator packs in the DS, they don’t know what they are talking about. The clock in the DS isn’t really a clock, it’s a (single) VCXO and it’s the highest quality device available for it’s purpose at the this time. That’s precisely what I’m talking about: upgrades that are irrelevant or will lower the sound quality. There are fine engineers out there who do good mods, but the DS isn’t like other DAC’s and modding it like other DAC’s will decrease sound quality or cause it to outright fail. I do list a number of possible mods which are reasonably cost effective and will increase sound quality. But you are free to spend your money as you want, after all, what do I know?
13 Likes
Between the Farad powering your ER and the DS transformer upgrade, which one do you get better SQ improvement?
I hesitate on the transformer upgrade since I would have to mock around with the DS, removing the analog card (not sure I feel confident doing it), sending it away, etc…