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Uncle Bulgaria · 13th Nov 2018, 5:15 pm

Thank you for the tip, Steve. I have the manual here, with a circuit diagram. I've attached it for future reference. The only one marked as 'metalised paper tubular' in the parts list is C19, which from my amateurish reading of the circuit appears to be something to do with setting the recording level. I'm confused as to what V5 does, as it seems to be after the output. Is C19 a bypass capacitor for the output from the second triode in the ECC83 envelope? Is the ECC83 providing the constant current (I think from the manual it is 1mA) that is the recording meter 'zero' point?

The other capacitors are marked as 'metal tubular', and one of these in the PSU (0.1mfd Metalmite Visconol-X) has measured badly.

13th Nov 2018, 5:15 pm	#7
Uncle Bulgaria Nonode Join Date: May 2016 Location: Cornwall, UK. Posts: 2,333	Re: Ferrograph 4A: Restoration advice needed Thank you for the tip, Steve. I have the manual here, with a circuit diagram. I've attached it for future reference. The only one marked as 'metalised paper tubular' in the parts list is C19, which from my amateurish reading of the circuit appears to be something to do with setting the recording level. I'm confused as to what V5 does, as it seems to be after the output. Is C19 a bypass capacitor for the output from the second triode in the ECC83 envelope? Is the ECC83 providing the constant current (I think from the manual it is 1mA) that is the recording meter 'zero' point? The other capacitors are marked as 'metal tubular', and one of these in the PSU (0.1mfd Metalmite Visconol-X) has measured badly. Attached Thumbnails