Modding the PS Audio Directstream DAC MK1 and MK2

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.

Any updates on the 8139 opamp modification WRT availablity and cost? Understood this is a send in your board modification. You have already performed the Vocm cap and nickel xformer mods. So pleased with this modded MK1, but if the 8139 opamps can provide further performance I’m interested. I suspect this mod will be an improvement, just not as night and day as the Vocm cap and nickle transformer mod, eh? 

Going to give the person some credit. First, they used nickel core APS transformers. Had the right idea on the Vocm mod, just the execution of not using suface mount and creating antennae. The added structural support for the capacitors is creative. Likely sounds good.

Must have been a difficult decision coming to the conclusion of no longer offering APS transformers for the MKII. A real loss for the MK2 community. Hopefully, when PS Audio gets its production issues sorted, you may consider revisiting the decision. 

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.

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.

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.    

The graphs are of interest; however, difficult to correlate to what one will hear. I found Mr. Richards numerical assessment of the sound quality improvement (see below) to be spot on. From my experience doing multi thousand dollar upgrades a worthwhile incremental upgrade of 1 is an excellent upgrade. For the MK1 the Vocm and APS nickel core transformers sound quality improvement going from a 6 to 9 is in line with my experience. Not a subtle upgrade. So happy. If I had not experienced, I simply would not believe the level of performance at this price point. Look forward to hearing from others with the MK2 to see if their assessment is similar.  

“We feel the new firmware made a large improvement in sound quality.

If I had to put numbers on it from 1-10

Stock MK1 6

Modded MK1 9

Stock MK2 with old firmware 8

Stock MK2 with new firmware 9

Modded MK2 with new firmware 10”

Spent a day revisiting the Snowmass 3.0.5 firmware in my Vocm APS xformer modded MK1. In my system, in my acoustic environment, and my ears I prefer Sunlight. Just my experience, YMMV.