Hi Bob Many thanks for the help. It's much appreciated. I do have an audio probe but luckily for me Andrea had spotted my basic mistake. On the layout there are some wires that are mentioned on the tube pins but for neatness and to save a load of lines all over the layout the actual wires were missed off. It was my mistake and luckily one I managed to rectify after I had mounted the PCB and attached all the pcb to tube wires (and there are a lot!) phew. So how it sounds perfect. Everything works as it should. Just need to double Check the FX loop as I only gave that a quick test.

So I have had another look at it today and am still getting the same voltages everywhere. It all seems to be hovering around the 520V. On all the test points on the tubes and the B+ points too. I checked my PT and that's giving me 120v which is fine. Then I'm getting 376v to D1-D4 on the HT. I'm getting 62v to the bias. 3.3v on each wire to the faux CT And 3.5v on each wire to the bridge rectifier. I have double checked all the wiring and so far I can't see a mistake. Does anyone have any bright ideas?

So I have had another look at it today and am still getting the same voltages everywhere. It all seems to be hovering around the 520V. On all the test points on the tubes and the B+ points too. I checked my PT and that's giving me 120v which is fine. Then I'm getting 376v to D1-D4 on the HT. I'm getting 62v to the bias. 3.3v on each wire to the faux CT And 3.5v on each wire to the bridge rectifier. I have double checked all the wiring and so far I can't see a mistake. Does anyone have any bright ideas?

Hi Andrea. There was no pops or bangs or smoke. In fact it has fired up perfectly every stage of the way which is why I'm stumped. Nothing is hot to the touch and the tubes are stone cold. Fuses have continuity across them so are fine. I have (give or take a volt or two) 515V across both sides of R56/57 and 58.