Review from Head-Fi.Org Forum

I know you were directing the Linear PSU question to jtwrace, though I have some experience running the Gemini 2000 using a Regulated Linear PSU (R-Core) by HD-Plex

Costs $USD 358

To answer your question, yes their is.

I found a significant improvement to the Gemini 2000 by using a Linear PSU.
I listened for 10 minutes to the PSU and then the Auralic supplied laptop charger went straight into the cupboard.

The Gemini 2000 needs a 19V supply ( … that is what the Auralic supplied Toshiba laptop charger provides, 19V with approximately 4 amp capacity I believe.
Also it is important that the DC lead supplied with the PSU has a 2.5mm DC plug, that is what fits into the Gemini. So if you decide on getting a Linear PSU
it is essential that the cable’s plug can fit as well as it being essential that is 19V).

The HD-Plex has 4 independent rails , 5V, 9V, 12V, and 19V … with total capacity of 100W.

I use the 12V for my Vaunix USB Hub, the 19V is being used for the Gemini 2000.
100W is available from the HD-Plex … I tested the power draw of the Gemini 2000, with kill-a-watt … it only use’s 12W.
I wanted a Linear PSU with plenty of “power headroom”, with a capacity of at least 4 times what was being used.
The Vaunix Hub only use 1W, so along with the 12W drawn by the Gemini 2000, I am only drawing 13W of the available 100W from the HD-Plex.

I spent a lot of time investigating Linear PSU’s and I narrowed it down to a Linear PSU with at least 2 rails, with both 12V and 19V available.
I ruled out Paul Hynes which is very well thought of, mainly due to cost and wait times (his is probably the Rolls Royce of PSU’s), though I was looking at his best PSU which is nearing $1K I believe.
So with a budget of less than $1K …. the contenders were PPA (Paul Pang Audio) and HD-Plex.
Paul Pang products are also highly respected (like Paul Hynes and Teddy Pardo products), Paul Pangs PSU was about $599 shipped though I found it difficult to find much feedback on the web.

I liked the price of the HD-Plex ($358) … though the HD-Plex also had one feature that really appealed to me, that is it used an R-Core transformer.
I read the information Solude wrote on his website
Power Supply, Filters
from my understanding of reading this, R-Core transformers appeared better than Toroid transformers (in a PSU).
The HD-Plex PSU had a R-Core transformer so that is what influenced me to purchase it.
The other thing with Regulated Linear PSU’s to watch for is the amount of ripple (that is how good is the Regulators in the PSU).
The HD-Plex has very low ripple … plus they got it measured (as well as getting it CE approved).
It was a extremely close call between the PPA (due to his very good reputation) and the HD-Plex, though for the reasons above is why I went with HD-Plex.

One thing to note with HD-Plex was before I ordered on the HD-Plex website, I was unsure if the supplied XLR-to-DC plug lead had a 2.5mm DC plug… so I asked for an extra lead.
Larry from HD-Plex answered my query in 2 minutes and promised to send one (I just had to make a note of it in my order).
When the HD-Plex arrived, the standard XLR-to-DC cable only had a 2.1mm plug … it would not fit into the back of the Gemini.
Though the next day, a separate package arrived from HD-Plex and that cable was a XLR-to-DC cable with a 2.5mm DC plug , so I was able to now power the Gemini.
As an aside, Larry did not charge me for the extra cable and kept his word (supplying me with an extra cable, which had a 2.5mm DC plug), so I had a very good experience with his company.

To give some context on the degree this upgrade provided, I consider it significant.
My Audeze LCD3 got an overall improvement of about 30% better, when I upgraded from the DACmini CX (an affordable DAC/AMP which I highly respect) to the Auralic Gemini 2000.
Adding the Linear PSU improved the Gemini by another 30% IMO… it was just as important as doing the DAC/AMP upgrade.
The noise floor dropped further, wider soundstage, I heard more detail, more control, more clarity, better micro & macro dynamics and tone.
It pretty much just enhanced the improvements that I heard with upgrading to the Gemini.
It was a much more significant tweak than the Vaunix USB Hub powered by the Vaunix SMPS (though the Vaunix gave me better timing and PRAT, the Vaunix actually did scale up quite well once it was also powered by the HD-Plex, rather than using it’s SMPS wall wart. The Vaunix powered by the HD-Plex is now a definite keeper, a much better upgrade than say a HP cable upgrade.)

Anyway, that is the best I can articulate the improvements of providing a better power supply to the Gemini 2000.
It has been about a month now with using the HD-Plex …. though I wrote the following to a friend on Head-Fi a few days after getting the PSU…..

“Anyway , these are my chronicles of my “poor mans Vega/Taurus setup” (if I was to get a cost no object system, it would be that) … though by paying attention to power & USB & source , I actually wonder how close I have come to narrowing the gap of my “Lifestyle” product … I think I may actually be quite close, could potentially exceed it with the remaining tweaks. I wonder.

Going back to the HDPLEX, it was money very well spent.
The construction is superb, very solid.

Sound quality improvements … the widest soundstage ever from my LCD3 … surpass’s the HD800.
LCD3 now has pin point imaging of the HD800.
More controlled tuneful bass.
Hearing low level detail that I have never heard before (even though some of my songs I have been listening to since a teenager).
No mid range grain or treble glare (my pet hates) … unless it is in the recording.
Inflection (not sure of the audiophile term) … I think the human voice is the most powerful musical instrument, and the tone or inflection a singer selects to use is important to convey the emotion … anyway, the emotion is conveyed more effectively. I actually “get” more of the feeling the singer was trying to convey.
Complex or very dynamic music like orchestral … I use to notice that the LCD3 would lose control when on the DACmini on this type of music … though this issue is no more.
It is like the Auralic Gemini 2000/HDPLEX PSU combo has made the LCD3 it’s bitch.

At this stage I feel that all of the strengths of the HD800 have now been added to the LCD3 (sometimes superior to the HD800 as far as soundstaging / equal for imaging / equal for dynamics) … though the LCD3 strengths are even better due to the HDPLEX, as the LCD3 is now operating at it’s peak … with optimal power being provided to the Auralic Gemini 2000. I often only listen at 15 to 25 % volume, so really unsure of what the Auralic Taurus would offer as an upgrade even though it has more than double the power. So, out of all the tweaks I am extremely pleased with going for the HDPLEX (especially as I dithered between getting the Paul Pang Audio PSU and the HDPLEX for over a month … even though the HDPLEX is half the cost of the PPA PSU, I actually much more prefer the design of the HDPLEX from a sound quality perspective … that R-Core transformer type which more knowledgeable people than me seem to go crazy for. It’s built like a tank, released on November 15th in Hong Kong and arrived on November 18th in OZ).