pre amp and psu placement

Posted by: dektop100 on 14 August 2016

Most of my listening is through headphones these days - I have a Naim 82 and Supercap, an NH2 headphone amp powered by a HiCap. The primary source is an LP 12, Keel, Lingo, Ekos and DV xx2. 'phones are Sennheiser 650s. I don't have a dedicated rack for the electronics but I've tried to keep them apart from each other - though there is one 'stack' comprising: 82/Supercap and lowermost an unused 180 power amp. Recently I tried re ordering the 'stack' so that the 180 was between the pre amp and it's supply. This has made for a rather large improvement in SQ - both sonically and musically. The sound is clearer, more 'open', vibrant and alive. Music is more coherent too, with a greater sense of 'progression', flow and expressiveness. I'm hearing new details on familiar discs. My question to you 'pre-power' users is, how far are you keeping apart your electronics?

Posted on: 14 August 2016 by Foot tapper

Hi Desktop,

The transformer in your Supercap radiates a strong magnetic field, even though it is shielded.

As I understand it (note this qualification!), the magnetic field mainly radiates vertically, i.e. above & below the transformer. Hence, if you have one stack of equipment, then you want the most space you can manage between your sensitive, low voltage electronics (especially the phono stage & pre-amp) and your largest power supply transformer.

Better still is to have 2 stacks of equipment - the so called "brain" and "brawn" stacks. Brain for components that don't have a mains transformer in them; brawn for those with mains transformers.

I am one of the many people who used to have 1 rack, then switched to a brain & brawn arrangement. It's a considerable musical upgrade.

Hope this helps a little, FT

Posted on: 14 August 2016 by MDS

Very much agree with FT's advice here. Ideally a 2-stack 'brain' and 'brawn' arrangement gives the best isolation for the pre-amp. I was surprised at the scale of the improvement when I split my single rack and went to two. The system just seemed to relax.

If that isn't possible keep the vertical gap between Supercap and the 82 above it as big as your stack arrangement permits.

Posted on: 14 August 2016 by dektop100

Foot tapper posted:
Hi Desktop,
The transformer in your Supercap radiates a strong magnetic field, even though it is shielded.
As I understand it (note this qualification!), the magnetic field mainly radiates vertically, i.e. above & below the transformer. Hence, if you have one stack of equipment, then you want the most space you can manage between your sensitive, low voltage electronics (especially the phono stage & pre-amp) and your largest power supply transformer.
Better still is to have 2 stacks of equipment - the so called "brain" and "brawn" stacks. Brain for components that don't have a mains transformer in them; brawn for those with mains transformers.
I am one of the many people who used to have 1 rack, then switched to a brain & brawn arrangement. It's a considerable musical upgrade.
Hope this helps a little, FT

Thanks. I knew there was the potential for degradation - I didn't appreciate how severe it could be. I seem to remember some 'NMR' guys once telling me that magnetic fields 'fall off' quite quickly - more than an 'inverse square' - as is common with other forms of radiation. I believe many hifi racks leave the electronics rather close. My current equipment arrangements are a bit informal - with two distinct groups, but not properly organised along 'B n B' lines of thought.