I just yesterday took ownership of a LD MKIV SE, bought direct from David@little-tube.
Unpacked it and noticed the volume knob was very loose, but have learnt a 1.5mm allen will fix that.
But sadly I am having an issue where the left channel starts buzzing. It usually happens when the volume is lower then average, or during quiet sections of music. The buzzing goes away if I turn up the volume by about 20-30 percent, then back down. I can also rid the buzzing by tapping the top of the unit. I can also start buzzing by tapping the top. Unplugging the input cable does not stop it, when it's doing it no music can be heard through that channel.
First I thought it could be one of the tubes, so I swapped round both sets of tubes, the buzzing remains on the left side. I have had a play with the DIP switches, moving them all back and forth, before settling on 5x gain.
I have contacted David who has suggested I clean the tube pins with deoxidiser...but the buzzing occurs on the same channel even when I swap the tubes.
I can't think of anything else I can do to make the buzzing go away.
Anyone have any ideas? :)
Thank you for any advice!