Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: fdesalvo on February 24, 2021, 10:52:13 am

Title: '55/'56 5E3 on the bench - filament question
Post by: fdesalvo on February 24, 2021, 10:52:13 am

Hi, all.


I've got a late '55/early '56 5e3 on the bench.  Owner wanted a cap job, some protective mods (backup rect diodes/MOVs on OT secondary), and some noise reduction.  This is his amp, which is routinely gigged, so he has no cares of future value.  I've updated grounding after installing the protective mods and completing the cap job, but some hum remains from the heater circuit.  The pilot lamp housing only has a hot lug and as you'd expect, the filaments are ref'd to ground at each socket.  Have any of you updated this to twisted pair with an artificial CT to ground? 


TIA and I hope you all have been well


~f

Title: Re: '55/'56 5E3 on the bench - filament question
Post by: thetragichero on February 24, 2021, 10:59:30 am

sounds like a good plan to me, either two 100 ohm resistors or a humdinger pot of ye're feelin' fancy