As the title says I want to know your views on this: I have a receiver which requires 220 volts DC HT for the valve anodes and 12.6 volts DC for the heaters from a seperate PSU at the moment I have it run via a variac fed from an isolation TX the unfortunate thing is its audio output is a bit on the low side so I want to run it through an audio amplifier the thing is the amp has the mains neutral straight to chassis and one side of AF input also to the chassis so if I link the 2 beasts together my receiver RF Earth will also be taking the amps chassis to earth I could run it all from the isolation TX do you think that's the best option?
The usual fix in the old days was to have a double wound 1:1 audio transformer between the live chassis parts and the connectors for the audio to line inputs or in the case of radios also for external headphone sockets. Except on the HRO where the cans are at anode potential, which is not so good if your high impedance phones have exposed 6BA terminal bolts .
Much lighter and cheaper than a mains voltage transformer. Do be very wary of direct rectified mains supplies - you may think the chassis is neutral , but it will work and give no errors with the chassis live as well
I hope you are treating all this with the respect it deserves - I have had a very nasty surprise off the grub screw holding the volume control knob onto an old radio of that era. Originally the grub screw was back filled with some sort of wax, but the plug of it had dropped out.
The usual fix in the old days was to have a double wound 1:1 audio transformer between the live chassis parts and the connectors for the audio to line inputs or in the case of radios also for external headphone sockets. Except on the HRO where the cans are at anode potential, which is not so good if your high impedance phones have exposed 6BA terminal bolts .
Much lighter and cheaper than a mains voltage transformer. Do be very wary of direct rectified mains supplies - you may think the chassis is neutral , but it will work and give no errors with the chassis live as well
I hope you are treating all this with the respect it deserves - I have had a very nasty surprise off the grub screw holding the volume control knob onto an old radio of that era. Originally the grub screw was back filled with some sort of wax, but the plug of it had dropped out.
