Got my Stereomour in today and fired it up only to notice that the right channel had hum and had significantly lower volume. The Tube on the right had much less blue glow compared to the left. I swapped tubes to check that and was able to get the right channel to sound ok until I tapped the top plate which killed the sound on the right. I found one unsoldered connection on the tube socket which I soldered but am still having issues. This amp was assembled at Bottlehead and was recently shipped from another owner so I know it was working before shipping. Is there another connection around the tube socket which I should look at or just reflow all the solder points on the right tube?