Originally Posted by cburbs
I am also going to test out the following with the headphones when I have time.
Ive generally found a couple small very cheap tweaks can make a very nice difference in detail/tansparency, imaging, and staging for all qualities of components.
First is some type of isolation between the pc and the dac chip, either spdif toslink or spdif coaxial, optical has complete electrical isolation though higher jitter and coaxial uses a small isolation transformer(still some leakage but better than nothing, and lower jitter). If the digital to digital converter(DDC, usb to spdif/i2s/etc) has a decent low noise linear power supply and upgraded oscillator all the better.
Putting a hub chip before the usb input of the dac or ddc improves the usb signal integrity and reduces phy noise generated by error correction.
The ifi power supply is low noise but the output impedance is much higher and really masks micro detail for imaging/staging. The jameco linear supplies are decently low noise but have much better output impedance and are 1/4 the price.
If possible using low inductance quadrapole/star quad) dc cables into various digital components significantly reduces noise generated by the varied current draw of digital signals. Make em yourself for a couple bucks or find someone that will make them for cheap. Same goes for ac power cables for digital components. The varied current draw causes a noise generating voltage to develop across the inductance of the cable, lower inductance, lower noise.
And last removing as much common/traverse mode noise on the ac line as possible. It can be a bit more complicated but ive had a great experience with using Topaz line noise suppressing isolation transformers, very small 125va 250va units for headphone systems can be found for $30-80. Though it is imperative that full electrical isolation from the pc is used with these via toslink optical, as coaxial, ethernet, and usb isolators dont completely block high/low impedance leakage currents without the use of very specific and more expensive($250 used 400 new) power supplies. Theres also caution with the neutral line on the secondary, if grounded a gfci on the output is mandatory, if isolated the only risk is if 2 ungrounded metal chassis are used with ac inputs, and v+ shorts to chassis 1, v- shorts to chassis 2, and a person touches both chassis at the same time. A rare possibility but better to be informed.
PC USB >
Uptone USB Regen, powered by a Jameco LPS, the jameco feeds into a lt3042 regulator and then a star quad dc cable into the regen. The usb regen is a hub chip on steroids, with an upgraded xo and regulators, you can often find them used for $50.
Regen into a Breeze DU-U8, a ddc eith tcxo and lps
Optical from the duu8 to an Audio-GD NFB-11.
The NFB11 is the only component on a topaz 91092-32 and I use a star quad ac cable as well.
End result is perfect clean lifelike audio. While it doesnt have the absolute rendering of a balanced system with vastly upgraded power supplies and an i2s signal to the dac chip, it quite literally sounds better than those superior components if they dont also have the same tweaks.
I also use the hifiman he400is with this system, with some mods:
-dekoni lcd velour pads
-custom rear grills with 1/4" opening and very open cell foam
-sorbothane lined inner cups
-melamine fuzzors on the rear magnets(which i wouldnt recommend as it can be less reversible)