Modding the PS Audio Directstream DAC MK1 and MK2

Here is three of the five we compared.  The stock units are gone.

Can we purchase APS stickers like the ones shown above? You installed the Vocm and your nickel APS transformers. I do not consider it a DS anymore and would like to have a way of showing. Sent same message on your website.

Hello Guys.

Has anyone used silver bearing conductive adhesive instead of solder for the caps  with the Vocm mod?

There are some very low resistive ones to chose from and easy to apply without the danger overheating the SMD. Durability does not seem to be a factor according to the manufactures data sheet.The adhesives are not cheap but neither is a new board.My most concern is with sound quality.

Thanks .

Quote by georgeab

"Can we purchase APS stickers like the ones shown above?"

We started using these badges on our signature series DAC upgrades where we fine tune the DC offset and use the newer revised transformers in the MK1.

Using a preamp, we feel Firmware fpga1_208_Antero or the first fpga1 228 Massive sound better. The new fpga1 233 Massive is clearer and can have more detail and a larger stage however for us just doesn’t sound as "real". Just a little thin sounding for our taste. String instruments have lost their body and texture.

Hi Jeff. Was this evaluation done on a MkII with your trafos, or a stock unit, or both?

With our nickel transformers and stock. To us it sounds like a fake top end and lack of low/mid dynamics.

We like fpga1_208_Antero best. We also feel that both the MK1 and MK2 needs a preamp to sound it’s best just like most other DAC’s.

Do both the MKI and MKII use the same software and firmware?  

No.  The transformers are even different. .

We have decided to build and offer our external power boards.again.  We have many request for them.

PM if interested.

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.

The green LED indicates the external supply is power on and being used.

I overlooked the reason some didn't think Snowmass 3.05 sounded better than other versions.

We revisited this with the original Rev.1 transformers and the difference between the firmware is very close. We feel Windom or Sunlight do sound very good however with the new Signature Series MK1 DAC Snowmass definitely outshines the others.

Just wanted to post my limited experience with the APS transformers in the MKII. I’ve only had them playing 48 hours or so. I don’t know Jeff other than dealing with him through the purchase and install of the transformers, but what he and his son have created are a revelation. I have only dreamed of sound this good. The reference tracks I use have never sounded anything like this, even in more expensive systems. the purity of sound, the intimacy of vocals, the realism, staging and separation are abundant in spades. My system, being beryllium for mids and tweeters, along with an electrostatic super tweeter, can be brutal, letting you hear every shortcoming with sources. The APS transformer upgrade, in my system I think is bigger than an amp or preamp upgrade. As can be seen from the response curves Jeff posted, yes the treble is more extended and crystalline than the stock Edcore units. Buzzy brass from the Athena Rachmaninoff Symphonic dances sounded much more like real horns and less buzzy mess. I could hear much more of Bill Evans hands doing different things and get a much better sense of the piano’s soundboard in general. Right now I’m not using a preamp, so I’m only playing my DSMKII between 40 and 70, so when I finally put a preamp back in the system, I may hear even more goodness. I’m not running Massive firmware yet, as I didn’t want to change too many variable at once, but it will be interesting to hear if I like Massive more than Antero. I do hope Jeff decides to offer the MKII transformers again some day, as I’m trying to convince a friend with a MKII he needs to do this upgrade.

How much of an improvement are the new signature series MKI transformers, and is a trade in possible?

We are very excited about our new Signature Series Modded MK1 DAC.

Before the new mod the DC offset averages between 3.6mv and as high as 12mv. No unit we ever received here was below 3.6mv. Most were about 7mv or more. With our new DC offset tuning we get it down to 0.5mv or lower. Low frequency distortion is now much lower and the sound quality has increased quite a bit. We should start receiving reviews soon. We could not stop listening to ours last night.

They are back in stock now.

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.

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.

Another interesting fact is the Signature series will accept and playback DSD 128 (DSD 2X) via AES XLR.perfectly however the stock unit will only accept DSD 64.

@richardselectronics 

Following on that, about 2 years ago I had the then new PSA Gain Cell preamp which I found lacking a quality PS. I think the internal PS could be bypassed and a outboard LPS added. Seems right up your alley

Finally, JKRichards admitted that for the DirectStream DAC to sound good, it’s not enough just to swap the transformers and do the simple Vocm mod. You need a good power supply for the analog board.

People on the PS Audio forum (including myself) already installed these power supplies 2-3 years ago. And previously, you, Jeff, argued with me that you could NOT hear the difference with the additional power supply vs. without.

Now, waiting [another 2 years?] for you to admit that the stock power supply needs to be modified for all these mods to really showcase their best. Because the stock awful noisy power supply is still there in your "Signature plus" version.

Here's a free business idea for you. Modify the stock power supply and you will have a Statement version, that you could offer for the price of a new DirectStream MkII .

The DSD DAC already sounded good, before the upgrades, and better after the upgrades. Of course there's always room for improvements, by upgrading more of the internal components. 

Anton, Antony_s0s Please get your facts straight.

We don’t just do a simple Vocm mod like the weird “sandwich conglomeration you did. Who would even consider buying anything done that way? What a mess. We professionally change and add many other components and adjust the DC offset for our new R2 APS audio transformers. This lowers the low frequency distortion even more. I believe you purchased our old nickel transformers which show little difference if any at all with different power supplies. Things have changed a lot since we started using these new improved R2 audio transformers. What a difference they make. No one has ever used the power supply we are using including us until recently. We have tried many designs with very little improvements if any until we used these APS modified supplies together with our NEW R2 audio transformers and mods. Most internal supplies that others have performed in the past looks like a hack job at best that no one would want to pay good money for. Ours are done correctly and professionally. We warranty our DAC’s for a full year.

Unlike you, we have measured the stock power supply and found it is NOT noisy. There are another issues we discovered and corrected that you don’t know about. Imagine that😊. And no, schottky diodes are not the correct thing to do as you did. That creates other issues you are overlooking.

Our Signature Series PLUS is already a statement DAC that we feel sounds better than the new MK2 and all previous MK1’s.

If you don’t have anything constructive to say or add truthful information to this discussion besides your negative remarks and comments please go elsewhere. Your negative comments are not welcome here.

You did the same thing with TurboTK’s (tekaudiospecialties1) post. You only criticize others work and don’t add to the discussion with useful information..

No... Sorry, you would be the last person we would take any "free business ideas" from.

I might know the same about shortcomings of the stock power supply or maybe even more than you. Imagine that! But we won’t find out because I won’t share with you, so you can’t sell a $10 mod for $1000 (just a random number as an example).

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You measured and found it not noisy. LOL Tell it Amirm (audiosciencereview.com) who measured DirectStream DAC a long time ago.

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Come on, man, the stock power supply uses a SINGLE ML317 in simplistic configuration to feed the whole input board plus display and processor board (one cheap integrated circuit serves them all). And this is the foundation of your statement DAC? LOL

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I didn’t overlook anything. Because I rebuild the whole power supply ground up. Only the toroidal transformer and heat sinks remain from the stock power supply.

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Your original APS transformers with my complicated Vocm mod really showcase the difference with the additional power supply vs. without it. I don’t know, but it could be your simple / cheap Vocm mod that didn’t allow you to hear the difference in your modified DAC.

PS

Yes, I did the same withTurboTK. I told him that he is wasting his really brilliant ideas when he uses this stock power supply as is.

Ignorance is bliss.

Re-posting someone else old data. This is from years ago with a stock unit.

Guess you will never know what you are missing.