[TimMills]

Hello everyone. Thank you for taking time out of your day to look at my thread.

I'm new here and first of all should outline my skill level:
I can solder, (cables and connectors mainly) - I have built speakers and followed diagrams to put together kits of crossover boards... I can use a multimeter, & I have just bought a capacitor meter. My understanding of electronics is growing daily as I've been on a very steep learning curve for the past week with this amp. Uncle Doug on youtube has educated me a little in valve technology, and I've got hold of a schematic for the amp which at first made no sense at all, but now I've learnt a lot more, it does (to a degree). I am having great difficulty in relating the schematic to the physical wiring though as I have no layout/topology for it. I am a broadcast sound recordist of 20 years and a keen vintage hi-fi listener but this is the first piece of audio equipment I've tried to fix myself! Sadly my tiny brain really struggles with the physics and maths part of electronics. calculations of ohms, farads, amps leave me wishing I'd learnt it at school when I had a better working brain. Volts I'm better with, especially now that Uncle Doug has explained that both DC and AC can co-exist in the same wire!

I've been getting a little guidance from a retired electronics engineer via facebook and tested out voltages at certain points but we've come to a point of head scratching... here's the crux of the problem...

The phono preamp is not working... it comprises of 2 12AX7s v1 and v2 on the schematic which are heated from a filament tap from the output valves, as are the other 3 12AX7s that take care of tone controls (I think) - neither v1 or v2 are heating up however. they are wired in series and I've measured 20v going into v1 filament 1 and 10v coming out of filament 2 which feeds filament 1 of v2 (theres 10v on that terminal at v2) filament 2 of v2 however shows no voltage and the pin is soldered to the centre tap which I'm assuming goes to ground somewhere. I've noticed that the 3 other 12AX7 that are heating up, are wired for heating differently to v1 & v2 - My understanding of why is lacking here.

I'm hoping in an ideal world that someone on this forum has had a Trio w-41 on their bench, maybe with a similar problem, and can point out something blooming obvious that I can cope with using my fairly basic skills with soldering and wiring. I have no oscilloscope or signal checking equipment.
The Amp is working on the 3 inputs that bypass the preamp and sounds very nice indeed!.. I have gone to the trouble of furnishing it with a full set of new matched Sovtek valves (9 in total) so would dearly love to be able to get the phono stage working and enjoy some records with the valve tonality that I've come to learn is pretty fine indeed.
Thank you in advance for any help you can give me. Images are attached that will hopefully help...
Tim