Preamp Noise with High-Efficiency Speakers

Worth seeing if changes in location of preamp (and associated ICs, especially if not shielded) relative to surrounding gear and any other electric gear, power cords or appliances results in any change in the buzz level. If so, take note of where noise level is minimal and use that to help identify what the external source of the noise might be. Repositioning gear alone might be a practical solution. The further each piece is away physically from each other and other potential noise sources, the better. Flourescent and halogen lighting as well as dimming devices are also often culprits for causing noise and interference with other devices, as are many digital devices and devices with large power transformers, like many power amps for example. Use of mu-metal sheets to provide additional isolation is another cost effective option to help in many cases. I use mu metal as an external barrier around my phono step up transformer device. Low level phono sections/gear are the most noticeably sensitive usually to external sources of noise.

No doubt very high sensitivity speakers like Avantegarde up the ante in terms of need for that feeding them to keep noise levels minimal.

I had hum/noise issues with my phono rig that came to the forefront a few years back when I switched pre-amps and had to add a step up device to match my low output Denon DL103R to the new pre-amp (ARC sp16) phono section inputs. Location/orientation of devices and wires affected the level of hum. The source is most likely nearby power transformers, most likely mostly from teh outdoor heating and AC units on teh other side of the nearby wall. I solved the problem by placing the Electrocompaniet step up device I use inside a cylinder of mu metal foil. Its been dead quiet ever since.

Non of the speakers I had attached were high efficiency which would make the issue even harder to resolve no doubt.