Modding the PS Audio Directstream DAC MK1 and MK2

I managed to get the 8139 opamps working with the stock power supply. I just had to beef up and modify the up stream regulators / filters. I now have a schematic of the analog board.
Sound wise… Sweet.  We feel this MK1 is now better sounding than the modded MK2 by quite a bit.  Worth the effort for sure.

We will be offering this upgrade before the end of the month.

I have both the modded MK1 and a MK2 with Nickel transformers.

I can honestly say that I feel the MK1 sounds better than the stock MK2.  With the nickel transformers installed in the MK2, I feel it is just slightly better sounding however, I prefer the touch screen over the new interface in the MK2 and also not dealing with the issues the MK2 has currently.  The firmware updates have yet to correct these issues as well as supporting all the features promised.  Many features still do not work or work correctly. 

The MK2 USB input is better sounding than the MK1 however I just use the i2s input and install a shorting plug in the USB port.  Also, the USB input on the MK2 has some issues with some streamers that cause a loud noise when switching from DSD to PCM.

Quote:

I for one felt that there was that much enthusiasm for the mods of the Mk1 on the PS Audio forums that there was a push against it as it was taking sales away from the MK 2

So true. It used to be a fun place to hang out and help others. Any positive reviews seem to get deleted or moved to a private area.  Not much activity there anymore, Sad.

I feel the reason they are having a hard time selling the MK2 is because of all the issues with it, not because of people keeping the MK1 and modding them. These owners don’t feel it’s worth the upgrade price especially with all the issues and the lousy user interface. Most everyone likes the MK1 touch screen, reliability and great sound the MK1 is known for. Why pay so much more when you can have the same sound with the modded MK1.

My $.02

I don't understand how this thread has become a pissing contest !

I read the modifying a Direct Stream DAC Mk1 thread on the PS Audio forums several times , all 5000 + pages . There were a few people who obviously had the technical ability to offer suggestions for modifications to the DAC . The designer , Ted Smith included . Some did the mods themselves , others opted to ask the likes of jkrichards would he be prepared to do the mods for them . For me being in Australia meant that sending the DAC to the USA wasn't an option . So I purchased the parts  from  jkrichards and had them installed locally . APS transformers and vcom mod capacitors . I could have purchased the MK2 DAC but at $14000 AU it better be a hell of a lot better than the Mk 1 . So my starting point was to upgrade the MK1 . Best choice I could have made . I finally listen to the music and not my system . The comments about increased , cleaner Bass and mid range are true .The sibilance that I heard on some tracks is gone . And yes I did demo the MK 2 .

I couldn`t  be happier with my choice .  So why am I telling you all this ?

I thought the comments "It’s because you are a good seller." are unfair to jkr .Read the forum people asked jkr .  

If those upgrade options weren't offered , then I would not have had the opportunity to choose to make the changes to my MK 1 .

I for one felt that there was that much enthusiasm for the mods of the Mk1 on the PS Audio forums that there was a push against it as it was taking sales away from the MK 2 .

Here is the data on the 298D

BTW just so everyone understands the 298D series is not an electrolytic cap.  It's the new Vishay Solid Tantalum Chip Capacitors MICROTAN®

We use these as they are the largest value available that will fit in the 0805 space and has a low ESR, and 0.01 CV DC leakage value and are rated to operate over the temperature of +85 C.

We tested many capacitors and found these to be the best fit and best sounding.

The reason I opted to send my DAC to JK Richards to have the nickel transformers and VOCM mod installed, other than I wan't comfortable doing it myself, is not because of some great sales pitch, it's because of all the great feedback from others who either did the mod themselves or sent their DAC to Jeff. The improvements to my DAC exceeded my expectations. 

QUOTE:

"You could be right if you weren’t wrong. I have a dedicated streamer."

I believe you told us you are using a Bridge II board.

QUOTE:

"And as I've told it before (I think, I did on PS Audio forum), with a dedicated PSU for analog board, the Bridge card gets better power, and it doesn't spoil the sound of the DAC anymore (okay, not as much as it did before)."

Oh, I just realized, it's not APS transformers less sensitive to power supplies. It's Vocm mod makes any transformers less sensitive to power supplies.

But, anyway, I can still hear the difference between power supplies, power cords, and interconnects. 

I think your Bridge II card is flawing your listening. When we did testing, the Bridge card totally trashed the sound quality no matter what mods were done. I would not recommend using the Bridge card as one could never get the great sound these DS’s can provide. With our External Power Board one can A/B the sound difference by just turning off / on the external supply (the internal supply takes over automatically).

The panel of listeners we had could hear NO difference between the internal supply and external supply so it’s not just my opinion. This was also done with the XS4400 transformers as well as our nickel transformers.

The external supply makes no difference in our listening tests however the nickel transformers along with the Vocm mod makes a huge difference.

We had one member with the external power supply, XS4400 transformers and the Vocm mod that used it for several months.  We changed his transformers to the nickel ones and he was blown away.  He also could not hear any difference between internal supply and external power supply.

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: