Tianyun ZERO - Factory(?) Substituting Inferior Parts

I picked up a ZERO 24/192 today.

The Coax input is only syncing up to 48000hz. 16 or 24 works, just no support for 96 or 192khz. Optical works fine at all rates.

I took the top off the unit to see if there was an obvious problem with the unit.

The screw in the Coax jack has been overtorqued and its cracked. There is also no grounding shim. I checked the ground, and its fine.

I then tried a few sources and cables without luck.

Then I noticed that 6 of the 8 Elna Cerafine capacitors have been changed. In the Headphone amp, the 2 25V33uf caps right behind the volume knob are now Elna Silmic II 10V47uf. The other 2 to the right are still the Elna 16V100uf. On the Main Board, all 4 of the 25V47uf caps are now the Silmic II 10V47uf.

All of the 6 replaced Caps are lower spec, but the Silmic II are a new warmer capacitor that is supposed to be better sounding than the Cerafine. It could be that all of the caps were previously over specced for their role in the circuit - I don't know. There are several other substitutions throughout the unit.

I went ahead and pulled the DAC board to check the back side. The solder job was sloppy as hell. Solder across traces in a couple of places. No cold solder joints though. Reinstalled and still have the same problem with the coax input.

I am going to be getting the opamps and volume knob replaced ASAP. The volume currently tracks very unevenly below 3 o'clock. The volume literally fades in from the right. I can deal with this in the HD600's, but the Shures are unlistenable because of the balance issues.

I double check what I was seeing and took lots of pics. I will post them later on.

On the caps, sorry, noob here. Sorry. The ones I have are exactly the same as the ones in the other person's that is doing the HDAM upgrade on page 509ish in the main thread.

On the solder, it was just sloppy work. It looked like they would solder one thing and move on to the next and just leave a little trail of solder. Definitely not intentional. I broke out the Canon and the Macro lens to get pictures before I cleaned everything up. I will get the pics posted tomorrow.

Also, is it normal for the Zero to have a chemical / solvent smell inside? I have worked with a LOT of vintage gear and know all of the smells associated with older or damaged gear. The Zero is a new one on me.

Oh - one important thing - it sounds pretty good so far. I have opamps on order and I am working on getting the vol pot ordered. I think it has a lot of potential (the Zero - no pun intended on the vol pot ). On the quality, maybe I was expecting too much for $140

Looks like its a crapshoot then. My optical plays great with whatever I feed it. My coax looses sync at 96khz and above.

Is there a way to 100% verify that a chip is legit? In the last year I have seen articles in hi-fi mags about the Chinese industry. I remember them talking about one factory getting caught removing DAC labels and then silkscreening the labeling for a more expensive chip.

It would be nice to make sure that CS8416 is what its supposed to be, then start working back up the circuit to see whats causing the issues with bit rates not working on some units.

Could be.

I am also wondering if a 110/50 to 120/60 step up transformer would help.