Modding the PS Audio Directstream DAC MK1 and MK2

Attached is a sweep of the LUNDAHL LL1948Ag (silver) transformer for comparison. These transformers are some of the best and most expensive units made however are not that good in the DS.

Here is the Edcor XS4400 in 1:2.

And our nickel transformers.

Agree. Thanks for posting this. We feel these transformers are a much better investment than say $1000 power cables and it’s immediately noticeable and measurable.

The MK1 upgrade makes a lot more sense for many instead of the large investment in the MK2 which they still have not moved past Beta testing even thou they are and have advertised it as a "ready for market" product however we feel the MK2 transformers are a must over the currently configured Edcor’s being fitted in the MK2.  Look at the sweeps we have done of each.

Good hearing from you Todd.  Your mods look quite good.  JFET's have been popular for high end audio for quite some time.  I used them in a tube preamp I built many years ago.

I’m kind of on the fence.

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.

We of coarse did instant A/B listening test in our evaluation.

The UI update is great as now we can turn off the power to the WiFi chip inside the unit. The sample-rate screen is also welcoming.

Look up Weedeewap.  See the real reason these units are failing.

This hack job is why.

Yes they are different. The Edcor XS 4400 has 4 windings that can be configured in several ways. (4-center tapped coils. 2- primary and 2 secondary). PS audio just uses the two secondary coils in series without using the center taps. They use the series junction as the center tap. The Edcore is a cheap ($30.00) off the shelf transformer that can accommodate many devices. These Edcor transformers were not designed to do this however it seems to work however with a great loss. Ours are designed specifically for the MK2 or the MK1. That’s why they sound so good. Our transformers designed for the MK2 will not damage the analog board whatsoever as PS Audio is claiming in the link above. It’s impossible unless the technician does it improperly. We have been running our MK2’s continuously for a year now with no issues. We have many customers doing the same also with no issues. Our extensive testing using state of the art equipment shows better performance using APS transformers unlike the statements in the link above.  Using a properly installed APS Audio nickel transformer will NOT damage the board however an off the shelf transformer can as it would not have the correct wiring. This is a passive device that improves the sound quality of the MK2 by a large amount just like the ones designed for the MK1 which are a different design

This is so ridiculous as PS Audio contacted us and wanted us to license or sell them our transformers. I can post emails from them if necessary.

Here is the real culprit of failing analog boards in the PS Audio MK2 units.

Hack job hand soldered adapter boards being installed at PS Audio. Guess they ran of the proper parts so they hacked this in instead. If I paid the kind of money these units cost and found this I would be very upset.

Shall we say more?

Quote from driftingbunnies

"Luckily I don’t see that random PCB sticking out from my pictures of when I opened up my unit".

If anyone opens up their unit and see’s this just put it back together and ask for a replacement unit. It will eventually fail without any help.

I would know first hand if even one unit failed that we installed transformers in.  We have had none fail. They must be talking about someone doing a self install of some others transformers as we only sent out (2) two pairs for self install.  One has already commented here. The other is still going strong.

We did turn down one unit and refuse to install which had this hack job done to it.

As promised. We were busy yesterday measuring the Directstream MK2 DAC.

I knew we liked the previous Massive Beta best (in blue below). It measures and sound best to us.

As promised. We were busy yesterday measuring the Directstream MK2 DAC.

I knew we liked the previous Massive Beta best (in blue below). It measures and sound best to us.

Notice the HF roll-off on the stock unit Compared the a unit with the APS transformers installed.

Quote from emailists :

"This might sound crazy but maybe some of APS's customers can thrown in $40 each and buy Ted a pair of APS he can play with on a spare or pre production MkII.  I think it would yield better updates if Ted could also hear what it sounds like on a nicer transformer."

Unfortunately this will never happen with the MK2 or any other product they sell.  They have to fix issues with the parts they have already released.  Ted would not be alowed to do any programming changes on units with "non-official parts".

Your welcome.  You should give Firmware Snowmass 3.0.5 a try.  With it the MK1 will sound even better than the new MK2 with our transformers installed. It's the most musical sounding firmware ever.

We are deciding if we will even offer transformers for the MK2 any longer.  It doesn't deserve our transformers. PS Audio is causing us more headaches with all the flaws the MK2 exhibits. It's not easy telling customers that they received a bum unit that they need to send it back for a replacement unit before we would even consider installing transformers. 😞

OK... We have only 3 pairs of MK2 cores left and will not be offering them any longer after they are gone. 

Was browsing this AM and found this hack job.  This maybe worse than the first one posted.  At least he is not selling this for retail.

Vocm mod 🤣

This is how we do it.

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

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.

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.