HL tears the ES9038 DAC down to the bones for a full hardware upgrade! In stage 1 of upgrades, I worked on the analog side of the board, replacing nearly all the stock parts, including: resistors, DIP-8 sockets, and capacitors. The results have been impressive, giving a much more reference leaning tone. (ELNA SILMIC Super Gold included)
After spending weeks trying to figure out why I was getting random noise, coming out of my digital equipment, I found the cause. I noticed that it kept coming through, with nearly every op-amp. I figured out my DIP8 socket (on the ES9038 DAC) was faulty. It feels like it has lost all pin tension. The larger op-amps, especially those with lifted DIP8 adapters, tended to fall out of the socket. The review should be out in September. This is mainly due to the number of op-amps involved in the testing process. Which is also why, these sockets are very important.
I also acquired an UpTone Audio IsoRegen, as this is a must for HiFi on a Home-HPC. This totally isolates the USB 2.0 line from the power supply in the computer itself. This is something I had been wanting to get for a while. Got lucky and found one for less than half the normal cost. It looks to be barely used, with the stock power supply, all in great condition.
Tore down the AU-517 once again, to get at the Power & Protection circuit. I made a mistake in replacing the 10D7C silicon diodes and hoping this fixes the relay issue.
You can find the complete C-2 page here. Capacitors Used Include: ELNA SILMIC-II/SILMIC-II ARS/ToneRex, Nichicon Muse/Muse-ES/Fine Gold/FW and a Siemens/EPCOS 1uF MKP output capacitor. Previous Mod: 16V Zener Diode Mod to allow Modern Discrete Op-Amps from Burson Audio.
The first part of my Sansui AU-517/717 restore guide, from recapping to finding those pesky shorted diodes. Not to mention how daunting it is just to remove and then rewire all the PCB’s! Here I hope to help shed some light on the subject.