Just reporting something I did, today ... just in case anyone else has noise-floor problems.
When I built my ANs, I was always conscious of some hiss from the tweeters and a buzz from the mid-bass drivers ... low-level and probably not hearable at the listening position - but annoying all the same.
But I recently read a 'white paper' on reducing noise in amplifiers; it covered all the normal things like twisting wires together - but I did come across an idea which I'd never thought about before.
This was, to ideally have the L&R input RCAs located close to each other, to "reduce the loop area", But, if not - to attach an earth wire from the RCA earth tag on the Left input ... to the RCA earth tag on the Right input.
Normally, I do have both input RCAs close to each other in a build - but in the AN's case, due to the board layout inside the case, I had the input RCAs on the outer edges of the back panel ... so as to keep them as far away from the mains wiring as possible.
Anyway, attaching an earth wire between the input RCA earth tags (and routing this earth wire well clear of the mains wiring) ... has resulted in an absolutely quiet amplifier! 👍
When I built my ANs, I was always conscious of some hiss from the tweeters and a buzz from the mid-bass drivers ... low-level and probably not hearable at the listening position - but annoying all the same.
But I recently read a 'white paper' on reducing noise in amplifiers; it covered all the normal things like twisting wires together - but I did come across an idea which I'd never thought about before.
This was, to ideally have the L&R input RCAs located close to each other, to "reduce the loop area", But, if not - to attach an earth wire from the RCA earth tag on the Left input ... to the RCA earth tag on the Right input.
Normally, I do have both input RCAs close to each other in a build - but in the AN's case, due to the board layout inside the case, I had the input RCAs on the outer edges of the back panel ... so as to keep them as far away from the mains wiring as possible.
Anyway, attaching an earth wire between the input RCA earth tags (and routing this earth wire well clear of the mains wiring) ... has resulted in an absolutely quiet amplifier! 👍
@andyr
Thanks for your confirmations Andy! It agrees with the recommendations brought forth by Andrew Russell @Bonsai of Hifisonix if I am reading it correctly:
https://www.hifisonix.com/articles/reducing-loop-area-in-audio-power-amplifier-wiring/
Best,
Anand.
Thanks for your confirmations Andy! It agrees with the recommendations brought forth by Andrew Russell @Bonsai of Hifisonix if I am reading it correctly:
https://www.hifisonix.com/articles/reducing-loop-area-in-audio-power-amplifier-wiring/
Best,
Anand.
It was a different white paper that I read, Anand ... but it had similar diagrams - so maybe Andrew Russell had some input to the one I read. 👍
Another interesting point in the article - which I certainly have never tried - is to rotate your power transformer in a 60 deg arc; one position within this arc ... will produce the lowest noise from the spkrs! 😵
