Location: Coventry, England UK
Posts: 534
I'm Simon.
Apologies for hijacking slightly... What can cause hum to come through the speakers? It's buzzing through both tweeter and woofer also so no idea of the frequency. It's not a ground loop as I do have an amp which doesn't transmit it at all but 3-4 other amps I've tried all do it.
Don't know if it's DC or just dodgy mains. I'm using a dc blocker but it's not doing owt. Thing also is that all my gear with toroids in do have this mains noise but it's very quiet and can only be heard when ear pressed against the case and the room is silent. Even the hum from the speakers is low enough that it can't be heard from about 3ft away so It's not audible at the listening position. It just bugs me that it's there though.
When I stick my head under the stairs cupboard I hear the same noise/hum which makes me think it's dodgy mains... Maybe the 1 amp that doesn't transmit it has something in the circuit blocking it somehow?
Location: Coventry, England UK
Posts: 534
I'm Simon.
Just stuck my head under the cupboard with all the incoming mains and sounds like this noise is coming from a particular box (I'm no expert but it doesn't look to be the main incoming, looks like something attached after, maybe it's polluting the mains). I've tried to capture it the best I can with the crap mic on my phone.
https://drive.google.com/file/d/1hh6...w?usp=drivesdk
Hope the link works ok.
I would also try turning the transformer as well, find that null point and things will improve
Coherent Systems
Real high end sound with musicality not hifi
Ah, I think I know what you mean now. Rotate them on the stud as if I’m trying to find a balance or equilibrium point?
Would this be a painstaking trial and error job? I’m assuming it’s unwise to handle the transformers while connected to mains power!?
Sent from my iPhone using Tapatalk
Location: London
Posts: 17
I'm Tommy.
Noratel is a good brand.
However also they can have the hum problem.
Special the older ones.
The newer Noratel is made better. Dc on the electricity net is more normal now then 10 years or even 5 years ago.
Now the Noratel take that in the consideration.
The Norwegian high End brand Musical Innovation made by Roar Malmin have always used the Noratel trafo. They are known to be very quiet.
A lot of people here in Norway did change to Noratel trafos because of the quality. Tommy
Source
SW1X Universal Music Server UMS I Signature with Power Supply Unit PSU I Signature
SW1X USB II
SW1X DAC III Special
Audiolab 6000 CDT transport
Amps
Pre amps -- Hi fi Collective twin mono ladder stepped attenuator, with Charcroft Z-foil and silver wired. And First Watt B1 active no gain buffer.
Power amps -- Welborne 45 SET monoblocks 1.8W / Decware Taboo 6W / Elekit 300B TU-8600SVK plus further improved components 9W / ICE Power 1000W
Speakers
Highly modified Endorphin P17 open baffle speakers containing both vintage and modern alnico drivers and paper cones. All silver wired - 8" Cube Audio FC8 full range drivers and vintage 15" Altec VOTT 416 bass drivers. All sat on Townsend Audio Podium seismic isolation platforms.
BK Electronics XLS400FF Sub.
Cabling
Silver mains cables, interconnects and speaker cables by SW1X
Headphones
HRT HeadStreamer and SennHeiser HD650 headphones