[mikeydee]

Thanks Crackle for the update. I recognise that drifting oscillator too when I had D16 in place. I haven't checked after removing but I will. As I suspect that is why my GM were all about 9.5-10 when I expected more like 11+

I saw your note about the alternative input source:

Not sure if I mentioned this before but I have fitted a means to disconnect the AC signal from the grid and inject an alternative signal through the patch panel.

Was that just a part of debugging option or do you have plans to be able to do listening tests or insert an separate oscillator. It sounds intriguing either way.