Modding the PS Audio Directstream DAC MK1 and MK2

The internal power supply is fine in the unit as there are many up stream regulators and filters. It’s not necessary to use an external supply for this reason however using an external supply will remove some heat from inside the DAC.

Also that bridge card destroys the sound of the DS DAC. Best to remove them.

We are the ones who designed and built the APS transformers.  We did extensive testing with all configurations of the DS.  This is how we know what improves the sound and what doesn't.

I didn't say there's no difference. There is. It's just my experience: power supply mod brought more changes than swapping 4400 with APS even WITH Vocm mod. 

The most of the things people described as APS transformers change in the sound: tight and beefy low end, melodic mids, and nimble highs - all these changes did my power supply mod after I installed the 4400 transformers. And APS transformers just tightened and cleaned up the same ALMOST perfect sound signature that I had with 4400 w/PSU before. Now, with APS transformers, it's perfect. 

Shame on me, I haven't done the Vocm mod before I swapped the 4400 with APS transformers... I  wish I could discern the Vcom mod impact on the sound. 

The XS4400 is not even in the same league as the custom designed nickel transformers.  Some of the "cheap" power supplies are designed better than some the the over priced supplies.  We know because we measure, test and sometimes modify them.

Our experience is just the opposite as with the nickel transformers the external supply makes little difference if any.

If you haven’t heard 4400 with a GOOD power supply unit (PSU), then you haven’t heard their full potential.

With GOOD PSU (not cheap Chinese stuff), the sound improvement from 4400 without PSU -> to -> 4400 with PSU was much bigger than 4400 w/PSU -> APS transformers w/PSU AND VOCM MOD.

I can’t say anything about sound improvements when 4400 swapped with APS WITHOUT PSU mod

This DAC upgrade is insanely good. I initially let it burn-in  non-stop via the USB stick on the PST, for 200 hrs, but the sound has continued to improve under normal use.

The soundstage is rock solid with vocals and instruments clearly defined and focused.  The soundstage has also expanded in all directions, creating more separation and air around the performers. And the bass, OMG the bass, is crazy good. Tight, punchy, and incredibly rhythmic. 

This is a component level upgrade, without the price tag. 

We feel the modded MK 1 with Vocm mod and nickel transformers sounds better than the stock ML2.

The MK2 with nickel transformers sounds just slightly better.

From 1-100:

MK2 99

MK1 98

I haven't heard the DSD MKII, but it's been mentioned by those who have, that the modded DSD MKI sounds better. I'm wondering though, how much better does the modded MKII sound compared to the modded MKI? 

From what I"m hearing from my modded MKI, It's hard to imagine the MKII could improve upon that. 

I came from the original xformers and had both the Vocm and nickel xformers installed. It is by a wide margin the biggest jump in sound quality of any electronics piece of gear I have purchased in my audio chain.... ever. I do recall reading on the PS Audio forum of folks who had gone from the Encore 4400 to the nickel xformers and they reported a significant increase in performance. Based on the design of the DS using the xformers as a low pass filter, my educated guess is the nickel xformers will provide the most significant improvment compared to Vocm mod.

WRT disappearing threads from the PS Audio forum. Huge props to PS Audio for hosting a forum that has a discussion of modding their products with input from the chief engineer. Interesting that you can discuss the mods, but they draw the line at describing what those mods sound like. I can understand that their focus is on selling their product and keeping interest in it. IMO, PS Audio could best serve their DS MK2 customers, by changing to a nickel core xformers in their MK2 and offer an upgrade path for those who have already purchased. IMO a used DS with this mod is likely the DAC performance to dollar king.    

Came from a stock DSD MKI. 

I did the Vocm mod for a friend several months ago.  He liked it however he thought his Holo Audio Spring 3 DAC sounded better.

a couple months later I upgraded his Edcor XS4400 to our Nickel transformers.  He loves the MK1 now better than the Spring 3.  He raved about it for several weeks.

Did you come from the original trafos or the 4400?

Can't give you a break down of the percentages of each mod, as I had Jeff install both mods for me. But I would estimate the percentage of both mods combined is easily a 50% improvement, but in terms of musical involvement and enjoyment, there's a night and day difference. Every parameter of the sound has improved. Considering the cost of the upgrades, even if you pay Jeff or someone else to install the mods, is a no brainer. 

For the people who made the VCOM mod and Richars’ transforms, what % quality increment would you assign to each mod? I ask because I’m getting the caps for the VCOM mod but I still haven’t been able to buy the transformers, I’m using the 4400.

What's up with the disappearing post's here? 

It seems the other forum is moving reviews of the Vocm mod and transformers to a members only area of their forum so only members can view them now.

Here is what is being moved to the private area:

kcleveland123

9d

Just received and installed JK Richards’ most excellent APS nickel core audio transformers in the Mk1 DAC. Very initial impressions are extremely positive. Have listened to two very familiar Lyle Lovett cuts so more to come later today and this weekend, but I’m really liking what I hear so far.

Also, @jkrichards tip to buy some kind of proper de-soldering station is brilliant. It took me about 5 minutes to remove both Edcor XS4400 transformers and another 10 minutes to solder in the new APS units. DAC powered right up and worked the first time. Yay!

Update: Thanks to JK Richards for pointing out the need for the Vocm upgrade as part of the nickel transformer swap. Bought a magnifying lamp and discovered I can still handle surface mount parts without too much fuss.

Just finished this and playing some more classic Lyle Lovett. Man this DAC is getting absurdly great.

Much lower distortion. The nickel is just part of the equation in making a great transparent audio transformer.  We design these specifically for the MK1 or the MK2.  They are not interchangeable.  

I'm curious what properties nickel has that gives it an advantage over iron transformers? I still can't believe how much better the PS Audio DSD MKI sounds after replacing the off the shelf transformers with nickel transformers and upgrading the caps. 

No schematics on the MK2.

Good to know you found a good replacement power transformer.

Thanks for the info.

And may I ask, do we have any schematic info on the Mk2? Output section in particular? Thanks, TK

Speaking of heat sink heat, I had to replace the transformer in a Mk1 this past week. But the original is a custom unit rated 8v secondaries, 2 x 25VA and not available. I chose an off the shelf 6V rated out 2 x 25VA unit and tg it's working fine, with less heat across the linear regs too of course. It's actually delivering about 7.4V AC V out in mine. The original toroid has a band shield, and there was room in there to wrap a band shield around the new one. I went with this one: Triad- VPT12_4170

TK

There is nothing to worry about however there is 4 heat sinks, two of which are not being used or at least not very much (without the Bridge installed) and do not get hot.  By installing a heat spreading material between these heat sinks distributes the heat more evenly.  I have used M.2 heat spreading material.

Just gently spread the heat sinks slightly apart and slide the heat sink pad (for a M.2) it between the heat sinks. I held the heat sinks together with a U shaped metal spring wire I made up.

Hey Jeff I thought the heat sinks with the mod installed would get hot?  Is there a way to correct this?  Or is it not something to worry about?  

HERE:

@richardselectronics 

You will be very happy. 

Sent my DS1 analog board for modification today. After re-visiting the 5000+ post thread pretty excited about this mod. Interesting to see the evolution of mods. Folks were really pleased with the results of Encore XS4400 (used in MK2) and Lundahl xformer, but designing xformer for this specific application appears to be the way to go. The Vocm mod was also universally loved by those that accomplished. Glad I came upon this and look forward to listening to the results.

First pair of APS audio nickel transformers for the NEW Directstream DAC MK2.

Read first post

Having a DirectStream MK1 that's really cool.  I'm interested in the upgrades but have been unable to locate any contact information regarding.🙄

I am interested in this Mod', I have only learnt of this option today, even though I have seen in the past other references to a Transformer and Fuse exchange.

Is there a Ballpark Figure that can be supplied for the purchasing of all the necessary parts required for the full Upgrade?

I am only a few years into taking a Digital Source seriously and commenced using it in conjunction with the long-term used Analogue Source. I took to digital as duck does to water, and there is no conflict between the hard media types when used in my system, each are embraced for their merits.

At present I use a PS PWT MkII > Bespoke Built Valve DAC, and have been interested in having a SS DAC as a option as well. I have been demonstrated SS DAC's up to a value of £5000ish, in systems I am familiar with and not familiar with, but have yet to discover one that has really made the idea of a Home Demo' seem worthwhile.

Maybe not of too much interest to this thread, but during some of the DAC Demo's there has been the use of different hook up methods and during the short periods of trials, I always seem to prefer the Coax Cable over others used.  

The method under discussion for Mod's does seem to produce a DAC that is competitive with high price tag models for a reasonable cost, as well as offer a further option for a DAC to be used when carrying out Streamer > DAC investigation, which is yet to take place. For this reason my attention is captured. 

What heat issue?

I'm curious about the heat issue.  I know having the external power supply will reduce the heat issue but how do we obtain the parts to use the external power supply?   Thanks!

I can see Paul shaking his head right now

I use this one. The DS has several local regulators so it’s not super critical. 
 

https://www.aliexpress.us/item/2255800739878853

Wow Jeff these power boards are elegantly designed. Thats more plug and play than I would have ever expected. 

I know this is a hard question to answer, but how "good" of an external PSU is needed to make a sonic improvement? Would a mid-level Chinese eBay linear PSU be better than what's in the unit already? Or is a top-flight linear needed to make a difference? (Obviously a better supply is a better choice but I am wondering how high/low the baseline internal PS is)

Glad you are enjoying your MK1.  The USB shorting plugs makes a big improvement If you are not using that port.

Jeff

Been letting my upgraded DAC continue to break in when not listening via the USB stick on the PST. Listening this morning and the sound has continued to improve. Soundstage has expanded and image specificity has become more pinpoint and focused. Overall the music has become even more satisfying and intoxicating to listen to, leaving me grinning ear to ear. Thank you so much Jeff for making these upgrades available. Once everything settles in I'll be ordering the shorting plugs. 

MK2 transformers will be available in June.

If you do trash your analog board, it is not the end of the world. I performed the xformer mod. Difficult to remove xformer without a quality solder sucker. Although I thought it was performed properly, I had some intermittant noise. Sent to PS Audio who replaced the audio board for $300. So it was $300 plus shipping to PS Audio. I was expecting the repair it to be much more expensive. Hats off to PS Audio.

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.

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.

 

This is what everyone will receive.

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

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.