SU-2 DIY iFi iPower X to DC-DC Converter Power Supply retrofit provides significant Audible Improvements
I owned the Matrix, SingXer SU-6 and lastly, the SU-2 and didn't find any appreciable differences between the three of them.
Nor did I feel they made any meaningful improvement over my USB straight to my DAC.
I bought the SU-2 because I wanted to try its 10MHz external clock input.
I tried it first with an inexpensive ($79?) OCXO from China and it made perhaps a 5% improvement in expanded soundstaging.
So I went for the Mutec REF10 SE120 and it improved my system's SQ by about 15% on top of the budget OCXO when connected to the SU-2.
I was intrigued by John Swenson's thread on DIY DC Power Cables where he asserted that Digital circuits don't typically draw steady state current and to accommodate their instantaneous current draws, Star-Quad DC cables provide minimal inductance/impedance for optimal performance.
https://audiophilestyle.com/forums/topic/31554-diy-dc-power-cables/#comment-653868
Following that, Antipodes Audio announced their new "Fast" power supply which I upgraded to in my server and player.
Antipodes' first iteration was a [Texas Instruments] TI DC-DC Converter fed by an R Core transformer.
Antipodes referred to it as a Hybrid Linear/SMPS Power Supply.
Antipodes later announced a Phase 2 upgrade, replacing the R Core transformer with an SMPS - feeding the same DC-DC converter.
They weren't offering this Phase 2 upgrade on my "older" units as there wasn't enough space inside the chassis.
So I removed the R Core transformer and replaced it with an iFi Elite SMPS.
The result was a 50% improvement over the original 25% improvement of just the TI DC-DC converter.
I owned a Ferrum Hypsos Hybrid PS for a while which I used on my EtherRegen, which I also feed 10MHz external clock to.
The EtherRegen thrives on a good external clock.
Then I started comparing the Hypsos with the iPower SMPS feeding the TI DC-DC converter and found the inexpensive DIY combo was convincingly better than the Hypsos.
Now nearly all of my digital circuits are fed by an iFI Elite or iPower X to TI DC-DC converters. [DAC, Phoenix Regen, EtherRegen, Server, Player-Streamer, SU-2 DDC, Home Theater Processor, Firestick, Cable Modem, Fiber Repeater]
For the SU-2, I used a 5V iPower X [no earth ground] to a TI DC-DC converter [Part # TPSM63606EVM] optioned for 5V to replace the SU-2 LPS .
I heard a 30% improvement in terms of expanded soundstage/holography.
The DC-DC converter can be fed up to 36V input and can be jumper configured for different outputs - 1.8V, 2.5, 3.3V, 5V, 12V
Other resistors can be soldered to the board to configure other voltages but it's a little tricky as you're on your own. I've done 9V and 1.2V
The SU-2 project -
I bought an aftermarket $60 5V iPower X and the TI DC-DC converter can be purchased from DigiKey [or Mouser] for ~$60
https://www.digikey.com/en/products/detail/texas-instruments/TPSM63606EVM/15666796
The iPower X output consistently measures 5.24VDC on each of the five units I own and the TI DC-DC converter optioned for 5V outputs 4.94VDC regardless of input voltage.
You can choose a higher voltage iPower X to feed the DC-DC converter if you want to.
I found the audiophile generalization of "A good LPS is better than an SMPS" to be a myth after trying this.
Although admittedly, I have not had any interest in trying these on any analog circuitry - preamp, analog section of my DAC .
I own a Phoenix USB Regen which uses a custom designed dual 5V Sean Jacobs LPS - one feeding the OCXO and the other feeding the USB chip and circuitry.
I replaced the SJ LPS to the USB circuitry with the iPower X and TI DC-DC converter and there was a 15% improvement in holography.
On my Antipodes EX Player, I replaced the motherboard-provided 5V USB power with the iPower X/DC-DC converter and the holography and ease improved significantly.
Following that, I found further, that feeding the digital chips directly provides noticeably higher resolution than through an existing linear voltage regulator.
I decided to take this route on the SU-2 recently - instead of feeding the 5V [4.94V] to the main PS input to the SU-2 board, I used two additional DC-DC converters - one optioned for 3.3V and the other custom optioned for 1.2V [custom mod-it doesn't have jumper provision for this on the eval board] to replace the linear regulators to the right of the top Accusilicon XO [see image]. This added another very noticeable level of holography, resolution and palpability to the presentation.
For my first implementation, to keep it simple, I made an aluminum plate with DC jack to replace the AC IEC receptacle.
I tried the 5V iPower direct to the SU-2 digital board. I also used a good earth ground to chassis for digital ground.
From memory, I'd say it was about a 7.5% improvement.
Afterwards, I was able to "fit" the added TI DC-DC converter Eval board in the space in back of the front panel.
When I heard the additional SQ improvement, I removed the SU-2 LPS board and fit the naked iPower X PS board in a sealed aluminum box in the SU-2 LPS space. [improvisation required and requires a small TORX driver to remove iPower X plastic case ]
https://www.amazon.com/dp/B015334MMA?ref=ppx_yo2ov_dt_b_product_details&th=1
I also found that replacing the fused IEC inlet with a direct, unfused IEC inlet improved the sound slightly. [Improv and cutting said metal plate with Dremel cutting wheel for IEC]. Ground pin on IEC connected to chassis as was original fused IEC.
https://www.ebay.com/itm/125262497618
The iPower SMPS, which in stock form, directly plugs into the wall, has its own protection internally.
FWIW
], they sure are convenient.
