About this blog
After reading the clock upgrade to the Uptone USB Regen blog, I am inspired to investigate what's possible on the Auralic Vega DAC.
About 20 years ago, I got Wadia's factory upgrade for the clock to the 27 DAC. Back then, the only details I could get were that the 20ppm accuracy clock was upgraded to a new 5ppm which was leading edge for TXCO at the time [- I did read the distinctions in the regen blog for measuring phase noise at 10Hz vs the marketing hype of fS jitter specs @ 100KHz :)] .
The new clock produced a major snap into focus of the soundstage as well as an improvement to the naturalness of the sound. However, as time goes on, as with most mods, the changes that I initially perceived were not near the level of perfection that I could settle for. I then got inspired to power each of the Wadia circuits by battery. The first circuit I converted was the clock. It was significant. The analog Op Amps also benefitted significantly from battery.
If the Vega is using a 20ppm then I am open to seeing if I can reproduce a similar magnitude of improvement to the Vega.
According to the Stereophile review, the Sabre DAC lies underneath the black metal plate labeled "AURALiC DSD DXD".
I'm guessing the clock is also underneath that plate next to the DAC. If so, does anyone have any experience with removing that plate? There appear to be two solder points on the front of the plate and two on the rear. I'm willing to take the plunge.
Entries in this blog
I recently replaced the bridge rectifiers with CREE SiC Schotty diodes in my Vega DAC and then Antipodes DX music server with very positive results. Mainly enhanced resolution, better space, blacker backgrounds, wider soundstaging and removal of glare. I had read some very old posts that advised against using Schottky diodes for audio power amps but these posts were ten years old so after getting good results from my front end I took a leap that these newer CREE SiC diodes would deliver in my Krell amp. When I first powered the amp up after the mod it initially sounded better but as time went by the sound got very squirrelly with a lot of added glare. After then adding shunting cap and resistor across each of the diodes and then across the secondary windings it marginally improved but something was still very wrong. I deduced that the Schottky's in the amp must be emitting EMI into the circuitry which I planned to absorb with some leftover TI shield which I have laying around. Maybe, as an outside possibility a neighbor coincidentally added some AC load that helped pollute the line. I could go back to the original 35A bridge rectifier in the amp to see what that sounds like but the more times you touch a mod in a tight space, the more you risk of breaking joints/wires etc...
I randomly had planned on doing an AC line filter plugged into outlets distributed throughout the house and admittedly better lucky than good, this not only fixed whatever was occurring after the amp Schottky mod but took my system to the next level in lowering noise and glare and delivering spacial detail that I had to tell people about.
I believe this inexpensive mod will incrementally improve many-a-system for the cost of about $2 per filter.
The cap is a WIMA part number MKX2AW21002C00KSSD which is a premium .01uF "X" capacitor meant to be applied across the AC line. It is rated for 305V continuous but is meant to take pulses of thousands of volts across the line and if overwhelmed by a lightning hit, is designed to blow open and not short like other capacitors....
The size of this specific cap happens to fit perfectly into the rectangular cavity inside a 97cent Cooper Wiring Devices 2601W-BU Plug which passes the WAF in the 12 outlets I have these plugged into so far. I used WBT silver solder to solder the 1" 26AWG leads to the cap and I dipped the other end of the leads that I compression fit to the plug with CAIG contact enhancer. I opened the prongs which revealed a small opening near the hinge for the 26AWG leads. When the prongs are closed it will hold the wire with a tight compression fit. The 1" or so leads allow the cap to insert to the cavity sideways then rotated 90 degrees to fit into the rectangular cavity in the back of the plug housing. I used a woodblock to push and compress the plug prongs all the way into the housing. Then I checked with a continuity meter to make sure nothing was shorted and then measured the capacitance. It took me doing two or three units to get the hang of it.
I plan on doing the other 18 plugs in the next several days as I ran out of silver solder. The more plugs added the less effect the antennae effect of the house wiring and noise polluting loads will have.