Audiovalve RKV MKII Impression and Mod

[rexhu100]

Bought this amp from a fellow headfier. This is going to be my end game amp for the foreseeable future. I plan to try it with different can and improve its performance through various mods. Being a noob DIYer myself, I would appreciate all the help and advices I can get from our community.

A glimpse of the beauty...

 

[rexhu100]

Day 0 Impression:

My very first impression: it is HEAVY! It is a workout taking it from my car to the house.

This RKV MKII is the older version that is different from the one on sale on Audiovalve's website, and you can definitely tell that it went through some usage in its previous owners. But you can simply tell from touching it that it is built like a tank! Its exterior design to me resembles German's famous Tiger Tank's turret. So I don't think a few scratches going to anything to it.

The first pair of headphone that I tried with it is the HD600, and I can bet that it has been sitting in the corner unused for a while. There is significant popping noises when turning the pot, and the overall noise floor is pretty significant too. I can start to hear noise without turning the volume too high. Nevertheless, I can immediately hear the wider and deeper sound stage and better extension in both the low and high frequency (my reference point is Little Dot MKIII). The noise reduced a lot after a couple of hours of listening, but it still bothers me. I guess I'll need to find out how to get rid of it...

 

[rexhu100]

Some scratches on the acrylic top... No biggie though.


The pot definitely reveals the unit's age

 

[rexhu100]

After some quick research online, I found that the dirty connections on the tubes can be a big cause for noise. Based on the overall condition of the inside of the amp (picture below), I guess the tube connection might not be too good. As you can see in the picture, there are plenty of dirt everywhere inside the amp. So I removed the tubes to check the conditions on their pins...

As expected, there are plenty of oxidation built up on the pins of the tubes. So I quickly got to work and started cleaning the tube pins. I used a small piece of sand paper to clean the oxidation, and then clean the residue using some rubbing alcohol. Then I repeatedly insert and remove the tube to their sockets to clean the tube sockets.

With some elbow grease, all 4 tubes are cleaned, and I also did a thorough dusting of the inside of the amp. Now everything (on the outside at least) are in pristine condition, it's time to test the result... (accidentally gotten some rubbing alcohol on the tubes, and it wiped out the paint on the tubes)

I cannot believe how big a change this simple procedure brings! The noise level is greatly reduced. I can barely hear any noise when I plug in my VE Zen 2.0 and the noise is even lower with my HD600. I wouldn't call this "pitch black background", but this is a huge improvement, especially considering how little work that i did to achieve it.

Now I am very intrigued on other stuff that I can do to further improve its sound...