DK Design VS.1 Reference mkII - unequal volume

My sincere apologies for not responding sooner. I was new to posting and hadn't set up to receive an auto notification for any responses.  Also, life just took me away from stereo problems. But thank you for your responses.
Yes, I did correct the problem. I ended up having to change the volume controller in order to fix the problem. It was a long journey but I finally linked in with a contact in the US who sold me a controller. Then, I had to find someone will take it apart and install it. It wasn’t a matter of tubes being faulty as the lower volume was maintained even with switching tubes from left to right.

hello did you fix this issue?

Check your tubes. Sounds like one is about too go bad on you.

The DK is a hybrid design using a pair of small signal tubes in the preamp section. I would first suggest swapping the two tubes to see if the volume difference switches channels. If so, the problem is that you just need a new pair of tubes. If not, then it is probably an issue with the volume control tracking and that would have to be replaced.