Yes worth doing, means you can isolate it to a source or the amp, we can then proceed from there.
Yes worth doing, means you can isolate it to a source or the amp, we can then proceed from there.
I've now uploaded some video of the hum & cones flapping on both my La Scala's & Naim Speakers (easier to see on the Naim's):
https://www.youtube.com/watch?v=9JBn8A8WFzU
https://www.youtube.com/watch?v=j9DtfjsJziM
could be dc from amp. can you try another amp?
Also try moving the amp around, see if the hum changes/goes. Could be picking up RF from another component.
Seems to me more like the pre. The power-amp will usually produce a very slight hum through sensitive speakers, audible close up to the speakers, with nothing connected.
If the hum gets louder with pre connected and louder still with the pre switched on, it is likely to be the pre. Also, that thing with the volume control is worrying.
After lots of fettling, I think I can narrow it down to the Power Amp...
I set my Croft Integrated (active pre & power sections) to the speakers & powered up with nothing connected - very low hum but only if i put my ears very close to speakers - this hum doesn't go up & down with volume.
Connected my X40 Streamer and powered up, all is good no extra hum there.
I then connected a SS Power Amp (Cympol CPA3) to my speakers with no source connected to that - absolute silence. Same when I use my X40 as the pre so all is good there.
I then connected the Gate Pre Amp to the Cymbol PA & used the X40 as a source then. With nothing playing there is silence except when I tun the volume on the Gate up & down - no hum but a sort of white noise sound but again very low. When playing a source this way there's no hum either.
So I think it must be the PA - trouble is how do I solve it?
I would get it checked out by an engineer.. may be the start of dc getting onto the speakers, or it could be something else. You have said your not comfortable with electrics so getting it checked by someone that is is important in case it gets worse.
the amp could still be ok, and it is something that is affecting that amp but not your others, but getting it checked and either fixed or cleared of having a fault is the first step. Until that is done its difficult to be sure about anything else. :)
Alas everything is not always straightforward on these occasions
The usual cause of hum like this in a unbalanced audio system is a cable with a ground connection missing or broken - like a RCA cable looking OK externally but actually having a
broken connection for its ground. Suggest disconnect input cables to power amp... does hum disappear ? If Yes then fault is a input cable.requiring repair or replacement.
Opto coupling with a LDR attenuator enables total silence for audio attenuation- which is a amazing feature of LDR's that other preamps cannot match.