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Qwin
01-01-2017, 10:50
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.

http://www.jkwynn.co.uk///Project_Images/PDU/pdu_01.JPG

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.
The on/off switch is 2 pole and the internal wiring is a decent 2.5mm sq.
Pretty basic, but at £80, in a well built 1U x 19" case, I'm not complaining.
Being the tweaker that I am, I decided to give it some additional functionality.

http://www.jkwynn.co.uk///Project_Images/PDU/pdu_02.JPG

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.

http://www.jkwynn.co.uk///Project_Images/PDU/pdu_03.JPG

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......

http://www.jkwynn.co.uk///Project_Images/PDU/pdu_04.JPG

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.

http://www.jkwynn.co.uk///Project_Images/PDU/pdu_05.JPG

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.

Sovereign
01-01-2017, 11:35
Nice voltage, mine normally come in at 247v

struth
01-01-2017, 11:44
Nice job that. Be a few tweakers having a go soon i bet

Sovereign
01-01-2017, 11:46
The best thing I like about this approach is that you know longer have to use fuses anymore :clap:

RichB
01-01-2017, 12:05
A mate who's a guitar player has one of these in his rig. His version already has the display. Biggest problem we found in rehearsal rooms was if the voltage dipped too low, the Marshall rackmount amps he used would cut out.

May be fine for effects and preamps but he ended up not plugging his power amps into it and running them directly to a socket instead.

Qwin
01-01-2017, 13:22
The best thing I like about this approach is that you know longer have to use fuses anymore :clap:

Yes, one of the reasons I moved to IEC sockets.

My voltage usually runs a max of 3V either side of 240v depending on the time of day, most of the day being pretty close to 240v, it dropped to the illustrated 233v at tea time (peak) when I pulled 8.5amps with the kettle. The wiring in the house is ancient and the consumer unit runs fuse wire!

Rich - not sure if their is anything in the unit that would cause the voltage to dip so low as to cause the amps to trip. The internal wiring is 2.5mm sq (24amp), maybe the extension lead from the wall socket wasn't as beefy? I don't know enough about these things, to say whether there is anything on the small filter/spike board that would cause this. At least I can monitor the voltage now and if need be, run my power amp to a separate socket on its own, but it may not be a problem. The Furman units with a display cost many times more than this basic unit and have much more filter circuitry in them, which maybe could also have some effect on the amps? I'm guessing about that though.

Qwin
09-01-2017, 14:59
http://www.jkwynn.co.uk/Project_Images/PDU/pdu_06.JPG

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.

These Clipsal Series 56 plugs are difficult to get hold of in the UK, they are popular in Australia etc.
I got mine from an "Audio" seller on the bay, more snake oil than I could stomach, Cryogenic treated, slow buffed pins, Deoxit and a Silver plated fuse. Plain, as it comes, would have done for me.
I bought it because it was available in the UK and at £20 plus delivery was the cheapest rear entry plug I could find, they are usually HiFi plugs and £70+.

Strangely enough, there is an Italian seller on the Bay selling a Russ Andrews version of the Clipsal plug for £50 (Used). I would hate to think what he paid for it new, but hey, it had Silver plated pins. The #56P313 plugs can be bought direct, min qty 100 from China FOB price $7.01 USD each and for $6.00 if the qty is higher. I hate being ripped off and that is just taking the proverbial. There are a couple of UK, Trade only, electrical wholesalers that stock them, but you need an account to see the prices. These will be the plain plugs without any added serpent lubricant, so google the part number if you have a friendly electrical trader that will purchase them for you. They also come in Grey with a clear middle, which is the most popular version with the Audio outlets.

That just about winds up this exercise. :)

Edit: Tried the lead out on the unit last night, at 4:00pm the voltage at mine showed exactly 240v

Qwin
23-02-2017, 12:37
I tried the Furman unit in my system last night as a dry run for a couple of bake off's that are coming up.

Aauughhhhh! :eek:

Sounds bleedin awful. I had to double check I had everything connected correctly.
The midrange sounds clean and transparent, but I have lost all the dynamic range.
The description, that these things just suck the life out of the music seems appropriate.
Left it running for 24hrs, in case something needed burning in, but it made no difference.

I am now in the process of bypassing the filter circuit board so the box will then be just a straightforward distribution unit, which is all I needed in the first place. My advice would be to buy a case, a switch and some IEC outlet strips and make a basic distribution unit yourself. A proper balanced supply is a different prospect, but I certainly would not recommend these filtering units.

Oh well, nothing ventured and all that. :rolleyes:

Ali Tait
23-02-2017, 12:54
Probably still worth having just for the neat box Ken, would cost more to buy all the bits to make your own I guess.

struth
23-02-2017, 13:11
Interesting... ive got the belkin purav unit and didnt find that with it. Not tried system without it for a long time of course, must try that sometime actually

Qwin
23-02-2017, 13:14
Aye, its a close thing on price, cases are not cheap if you do a diy job.

I would have preferred a deeper case (front to back) as the short one means you can't stack things on it.

struth
23-02-2017, 13:19
Look out for one of these

https://uploads.tapatalk-cdn.com/20170223/cf2f705e3d837700db9e36effe07ff67.jpg

Qwin
23-02-2017, 13:22
Interesting... ive got the belkin purav unit and didnt find that with it. Not tried system without it for a long time of course, must try that sometime actually

I can't comment on other units, but this basic Furman is the pits for sound quality, made Grace Jones "Nightclubbing" on vinyl sound flat, when it is a very dynamic album.

Bonky
23-02-2017, 18:30
Oh dear, I have one of those Pure AV units after lengthy advice on these forums some time ago. Are we now saying they are a waste of time and money?

(I know, I should do an A/B comparison...)




Look out for one of these

https://uploads.tapatalk-cdn.com/20170223/cf2f705e3d837700db9e36effe07ff67.jpg

struth
23-02-2017, 18:44
Im not... i like mine

Gazjam
23-02-2017, 22:17
Ken,
go balanced mains!

Stick the BMU unit in another room or cupboard and run some meaty soliid core spur mains cable from that through a drilled hole in the wall into a hard-wired 'hydra' in the listening room...
Can all be hidden out of sight.

hardcore, maybe, but short of a dedicated CU to your hifi the next best thing imo.
Didn't get on with mains filters tbh, not bad for sources but sucked the life out of amps I found.
Didn't have the big beastie Grant has, know a lot of folk liked them.

Ammonite Audio
24-02-2017, 10:37
Some years ago I was tempted to buy an Olson 'Sounds Fantastic' distribution block that incorporated an inline filter module and a screened input cable. Guess what? It sounded awful - very much reflecting your experience here. So, I ripped out the filter, replaced the inout cable with an old unterminated Kimber Powerkord that was lying around, and while I was at it, replaced the internal wiring with solid copper stripped out from ordinary twin and earth and insulated in teflon tubing. Result? Dynamics were back and the music with it.

This made me think that any form of inline mains power filtering is musically destructive. I've heard Isotek demonstrations where they went from no filtering, up the range to very extensive designs, and in every case I heard a progressive sweetening of the sound but with a progressive penalty in dynamics and musical interest. A few years ago I bought a Belkin PF30 following forum enthusiasm and it did the same - awful squashed effect on musical dynamics, but it did work well on the telly. A Tacima block was worse, and now powers my home broadband setup, in the hope that it will stop some or all of the switching PSU noise from squirting back into the rest of the house supply.

For anyone with mains problems, my advice would be to experiment with simple plug-in parallel filter devices; and if the problems are really bad, do as Gazjam suggests and look at balanced mains solutions, or for the wealthy a PS Audio Power Plant.

The annoying thing is that, according to objective electrical theory, none of this should make a difference, but sadly my experience is that it does.



I tried the Furman unit in my system last night as a dry run for a couple of bake off's that are coming up.

Aauughhhhh! :eek:

Sounds bleedin awful. I had to double check I had everything connected correctly.
The midrange sounds clean and transparent, but I have lost all the dynamic range.
The description, that these things just suck the life out of the music seems appropriate.
Left it running for 24hrs, in case something needed burning in, but it made no difference.

I am now in the process of bypassing the filter circuit board so the box will then be just a straightforward distribution unit, which is all I needed in the first place. My advice would be to buy a case, a switch and some IEC outlet strips and make a basic distribution unit yourself. A proper balanced supply is a different prospect, but I certainly would not recommend these filtering units.

Oh well, nothing ventured and all that. :rolleyes:

Qwin
24-02-2017, 10:39
Gaz - I initially didn't think a balanced supply was feasible for me, because of space limitations.
However, your idea of putting it in another room has merit as I already have a desk top computer and the air pump for my linear tracking tone arm in the next room. I installed some 22mm dia plastic tube through the wall to help the cables for these slide through. The desk top computer is no longer needed so I have spare capacity to run the PSU cable through.

Longer term this will now be my goal, a balanced supply in the next room feeding my distribution unit at the bottom of my rack.
Thanks for the tip. :thumbsup:

Qwin
24-02-2017, 13:54
Ammonite - When I read various reviews about these devices, there were folks for and those against, so for not a great outlay I gave it a whirl.

Like you, I found the results from this basic entry level item disappointing. I can't say about items further up the range, but I would be doubtful now of anything just claiming to be a filter.

The 60mm square PCB inside my unit, is now being used solely to power the "ON" LED.
I'm waiting for a couple of bus bars to arrive through the post, I'm joining all the outputs to the switched input and just passing the power through the unit unmolested.

Its still a useful item to me, purely as a power distribution unit, keeps my cabling tidy and short and a single easily accessible switch to isolate everything at the end of a session is handy. My added Volt/Amp meter will work as before. The plan is now to eventually build a balanced supply and feed this distribution unit from that. Lots of other things to complete first though. ;)

Gazjam
25-02-2017, 15:09
Gaz - I initially didn't think a balanced supply was feasible for me, because of space limitations.
However, your idea of putting it in another room has merit as I already have a desk top computer and the air pump for my linear tracking tone arm in the next room. I installed some 22mm dia plastic tube through the wall to help the cables for these slide through. The desk top computer is no longer needed so I have spare capacity to run the PSU cable through.

Longer term this will now be my goal, a balanced supply in the next room feeding my distribution unit at the bottom of my rack.
Thanks for the tip. :thumbsup:

Nice one Ken. :thumbsup:

Qwin
26-02-2017, 15:59
http://www.jkwynn.co.uk//Project_Images/PDU/pdu_07.JPG

I 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, 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 and ready for NEBO8 :)