I disconnected all interconnects and changed them round, no difference.
I did notice hum increase or decrease if I wiggled either of the power amp cables.
Ground Loop Hum
Re: Ground Loop Hum
I did notice hum increase or decrease if I wiggled either of the power amp cables.
Re: Ground Loop Hum
You definitely want the amps safety grounded - connected to mains earth in other words. Especially with valve amps in particular.
Its worth putting in half an hour to reposition the amps, cables etc to see if some re-routing could kill the hum for you. I take it these are commercial valve amps, or are they DIY ones?
Its worth putting in half an hour to reposition the amps, cables etc to see if some re-routing could kill the hum for you. I take it these are commercial valve amps, or are they DIY ones?
Do or do not, there is no try
Re: Ground Loop Hum
This clicks with me. I had a horrible hum and it was because my phono stage was too near the valve power amp. Not near in any obvious sense but still too near. Moved bits about... problem solved.
Vinyl -anything else is data storage.
Thorens TD124 Mk1 + Kuzma Stogi 12"arm, HANA Red, Gold Note PH 10 + PSU. ADI-2 Dac, Lector CDP7, Wyred4Sound pre, Airtight ATM1s, Klipsch Heresy IV, Misc Mains, RCA + XLR ICs, Tellurium Q spkr cable
Thorens TD124 Mk1 + Kuzma Stogi 12"arm, HANA Red, Gold Note PH 10 + PSU. ADI-2 Dac, Lector CDP7, Wyred4Sound pre, Airtight ATM1s, Klipsch Heresy IV, Misc Mains, RCA + XLR ICs, Tellurium Q spkr cable
Re: Ground Loop Hum
Croft valve amps, have had them for centuries, ha!Fran wrote: ↑Wed Feb 14, 2018 10:44 pm You definitely want the amps safety grounded - connected to mains earth in other words. Especially with valve amps in particular.
Its worth putting in half an hour to reposition the amps, cables etc to see if some re-routing could kill the hum for you. I take it these are commercial valve amps, or are they DIY ones?
Re: Ground Loop Hum
aghh.... doesn't everybody love ground
sd card player, modded soekris dac, class a lifepo4 amp or gb class a/b amp, diy open baffle speakers based on project audio mundorf trio 10's
Re: Ground Loop Hum
Somewhere to keep your feet.
NigeAmp, NigeSD DAC, Airtight ATM-4, Ruark Accolades, Pink Triangle TT, Roksan Artimiz, Clearaudio Discovery, Tom Evans Microgroove Plus, Fran DAC, Dalkey Audio Interconnects.
Re: Ground Loop Hum
Hhhmmm! So that's the best anybody can do!
Re: Ground Loop Hum
if you cant resolve it externally,
its probably time to look inside to see what way it was earth grounded and if it can be improved apon
if its crudely connected chassis earth to signal ground an alternative is likely to easily solve it
its probably time to look inside to see what way it was earth grounded and if it can be improved apon
if its crudely connected chassis earth to signal ground an alternative is likely to easily solve it
Last edited by nige2000 on Sat Feb 17, 2018 12:17 pm, edited 1 time in total.
sd card player, modded soekris dac, class a lifepo4 amp or gb class a/b amp, diy open baffle speakers based on project audio mundorf trio 10's
Re: Ground Loop Hum
Just wondering... I have the amps on a 3-tier Target stand. Power amp on top, preamp in middle, power amp at bottom.
Could the metal stand be having an influence?
Could the metal stand be having an influence?
Re: Ground Loop Hum
Is the preamp active or passive?
Are you confident opening up the bottom of the amp where there are lethal DC voltages - not like AC these are much more dangerous?
Are you confident opening up the bottom of the amp where there are lethal DC voltages - not like AC these are much more dangerous?
Do or do not, there is no try