Ayon CD5S Tube Replacement

@mikhaelkuz   
I just used the regular 6H30Pi. 

@csmgolf  thank you again! Did you use regular EH 6H30Pi, or "selected by vendor" (i.e. matched triodes, low microphonics, etc)?

It has been several months ago so I am not 100 percent certain, but I believe they were Sovtek. They were certainly nothing special (i.e. pricey NOS tubes). Knowing how it sounded with the inexpensive factory tubes, I had no problem going with the EH to replace them. 

@csmgolf 
Thank you for this info!
When you replaced tubes, what 6H30 were originally in? Sovtek?

It specifies (4) 6H30 and (4) 6Z4 in the manual. The 6Z4 are Chinese made tubes with very few substitutes. They are pretty inexpensive. I was experiencing some tube noise in mine and changed them all out. I used Electro Harmonix gold pin 6H30s, so the complete tube change out was less than $200. I can't say if NOS 6H30s would be an improvement over the EH, but I am satisfied with the result. 

I am an owner of  AYON CD-5 (bought used, but prob had very little hours on it, looked brand new), and it is really an amazing player (or DAC, as it used 80% of the time). I had the same question, and found on AYON S-3 manual on page 40 instruction on opening the unit, which has the same case as CD-5. But video indeed will be better.
Now I am thinking what tubes I should (and should I) replace. What tubes are actually inside - is it known?

It is best to watch the video that Gammajo mentions. It is not just removing the screws from the bottom, but also how the machine needs to be handled to prevent damage to the internals. I have a CD5s also and agree that it is a really nice player. 

This is a late post but may help anyone with the same question. I have the CD5s and certainly agree it is spectacular! It opens from the bottom with a special long Allen Wrench that reaches through holes in bottom. Call USA Tube Audio and they can send you a short video of opening the unit. Bets tubes to Replace the 6H30's are Russian Reflectors NOS from the mid 70's to 1980, they will take sounds to new level. The power supply tubes are good to go as the stock ones. These are all 10,000 hour tubes but I would consider replacing them when they are about 5 years old depending on use. Hope this helps!

It looks like you're going have to open this one from the bottom. First see if you can remove the door on top where the CD goes in. If it does come off, flip the player over. If not, rest in on one of the sides. 

The top should come off in one of 2 ways. Start by removing the bottom cover. (You may have to remove the feet to access all of the fasteners). Once the bottom is off, you may see a rod in each corner that runs from the bottom of the player and connects to the cover itself. If you do have the rods, there's a good chance you've already removed the fasteners that hold them in. If you have the CD player resting on its side, you need to be very careful because if it you removed the rod bolts in order to take the bottom off, the top will just fall out. I know this sounds complicated, but once you see it for yourself, its a very simple procedure.

Here's the other option. You need to remove the bottom for this way, as well. Once your inside, get a flashlight and start looking. You should see some type of rails that run around the inside permitter of the case. Those rails support the top cover, and they should also have some screws in them. Those are the screws that hold the top on. Remove them and it should come off. As with the above method, if you have the CD player on its side, make sure you are holding the top plate so that when you remove the last screw, it doesn't fall out.

If you're confused about the rods in my first example, do a google search for a Wadia 850, 860,861,27. (The case is exactly the same on all of them). If you look through the pics, you should have no problem finding one with the top cover off and the rods visible. But like I said before, its an easy job.

If you want a manual, call The Cable Company. They sell the entire line, and may actually be the importer (I'm not 100% on that, though). Either way, they'll help you get one. They also have a big selection of tubes. Ask them for a recommendation on what will work best. I can't vouch for them, but I can tell you that I've been dealing with them for 20+ years, and they have my complete trust. That's saying a lot because I don't trust anyone.