|I've been considering the pros and cons for my audio systems power needs for a while.
Like all things relating to HiFi there are polar opinions regarding mains filters, some swear by them and say they improved the sound of their system, others say they suck the life out of their power amps and wouldn't recommend them.
Ideally, I would go with a big transformer and a balanced output. (+120/0/-120V secondaries) 240v total across the output.
As I don't have the space for this, I will keep it simple, my main need is just a tidy way of distributing power to my gear and a 10amp unit should be enough to power my whole system.
I purchased one of these Furman M-10x E power distribution units from a Pro Audio (DJ) supplier.
The unit has a basic noise filter and spike protection, with a 10amp resettable trip on the back.
There is a single IEC c14 input socket on the back and x10 IEC c13 outlets.
The front has an additional outlet, an on/off switch and a Green LED to indicate it is functioning.
Pretty basic, but at £80, in a well built 1U 19" case, I'm not complaining.
Being the tweaker that I am, I decided to give it some additional functionality.
I got one of these Chinese AC Volt/Amp meters off the Bay (£7 delivered).
This will allow me to monitor the current draw, so I don't overload the distribution unit and keep an eye on the voltage available.
That's the meter wired in, I put a small switch on it's supply, so I can disable it if the constant display gets annoying.
I also changed the units "On" LED from Green to Blue to match the meter back-light and the rest of my kit.
The small board in the centre is the filter/spike protection, which seems nothing more advanced than you would find in a filtered multi way extension block. But that might be a good thing......
It looks smart when set into the panel and I'm pleased with myself for making the changes without scratching the front of the unit.
This is the reading when I plugged my kettle in to the back. There are adjustment pots inside the meter and I calibrated it so the readings match my multi meters at 240V and 9A settings.
This unit will do the job for me.
I finished the job with a decent mains lead, I will make up a short one for my living room, this one is 10m long for bake offs etc. It has pleanty of Copper, I used 2.5mm sq and its a flexible rubber jacket, I hate PVC, especially in cold weather. I put an IEC Locking connector on one end so it doesn't pull out of the unit under the weight of the cable, and a heavy duty IP66 (Weatherproof) UK 3 pin plug on the other (Clipsal # 56P313). I need a rear entry plug as some of my mains outlets are close to the floor and the thick cable wouldn't take the tight turn, plus these are very well made and a joy to wire up, even with the thick jacket and 2.5mm sq copper wire.
I tried the Furman unit and my new lead in my music system.
IT SOUNDS TERRIBLE!
Some people have said that this type of unit with basic mains filtering on board, just sucks the life out of the music.
I have to agree, Grace Jones "Nightclubbing" is a vinyl album with great dynamic range, but it just sounded Flat. The midrange was clean and transparent, but the top and bottom end had gone.
Oh well, you live and learn.
I will bypass the small filtering board and just feed the output sockets direct from the switched input.
installed a 240v/25amp bus bar, removed all the power leads from the
PCB and joined them together using that. I didn't remove the circuit
board as it powers the "ON" LED, but that is its only function now. The
power just flows through the unit unmolested, so it's truly just a
distribution unit now.
I tried the unit back in my music system and the result is fantastic, the music has full dynamic range again. In fact I would go as far as to say it sounds very slightly better, a bit crisper. Getting rid of the various cheap and nasty three pin distribution blocks with their Neon lights, switches, minimum level wiring and poor contacts seems to have improved things.
I've not done anything radical just used a decent thickness of copper in the leads and reasonable quality (not exotic) connectors, the result is very pleasing though.
MY SYSTEM IS NOW SOUNDING GREAT.