Hello from the UK

Hi everyone
Just a quick introduction before I post a querry for some advice.
Not a total newbie to this subject as I built my first crystal set some 40 years ago with numerous projects including breathing life back
into the odd valve radio.

It's only until now that I decided to design and build a valve stereo amplifier out of the parts I've collected over the years. It sounds good, well to my ears anyway but working on it for possible improvements now requires the advice of those far more knowledgeable than I. Any help would be greatly appreciated. Cheers