View Full Version : MCRU Entry Range PSU's
After months of development I now have a range of PSU's to replace the wall wart SMPS that comes with your DAC, Router or most of the other bits of kit involved with digital file playback etc.
A SMPS which is typically what is supplied with a lot of equipment these days due to costs of manufacture (cheap) and is usually of chinese manufacture and no thought of sound quality has taken place, just cost of manufacture which is usually a few pounds at most, even pence in some cases, these feed a lot of mains noise back into your system and do more harm than good.
The entry range of PSU's are realistically priced for anyone who wants an improvement over their stock SMPS without it costing more than the equipment itself. The major benefit is the PSU is up-gradeable and allows you to experiment with different mains leads as it has an IEC inlet as standard. It can also be up-graded to a higher specification when funds allow.
As standard the PSU is fitted with a detachable DC lead and a basic mains cable and will power many of today's popular items like the Cambridge DACmagic and the Caiman DAC as well as the SB and many of the Netgear routers which have noisy SMPS's as standard.
£99.95 plus delivery, pictures below, please pm for more details or purchase via my website (http://www.mains-cables-r-us.co.uk/power-supplies/333-mains-cables-r-us-dc-power-supply.html), please advise what item you are powering when placing your order.
http://i622.photobucket.com/albums/tt309/themainsman/PSU/DSCF3923.jpg (http://www.mains-cables-r-us.co.uk/power-supplies/333-mains-cables-r-us-dc-power-supply.html)
http://i622.photobucket.com/albums/tt309/themainsman/PSU/DSCF3924.jpg (http://www.mains-cables-r-us.co.uk/power-supplies/333-mains-cables-r-us-dc-power-supply.html)
http://i622.photobucket.com/albums/tt309/themainsman/PSU/DSCF3921.jpg (http://www.mains-cables-r-us.co.uk/power-supplies/333-mains-cables-r-us-dc-power-supply.html)
The Vinyl Adventure
14-08-2011, 21:55
What a bloody brilliant awesome stupendous idea David, you are a genius for coming up with the idea ;)
It's about time someone brought out an affordable upgrade PSU!
The Vinyl Adventure
14-08-2011, 22:01
... As it goes, I've had one powering my caiman over the weekend at 16v
It works a treat and is a lot smaller then and doesn't buzz like the CB psu I had running it before ... Pretty certain it has the edge on the sound quality too although I'm yet to do comprehensive comparison...
It's certainly better than the caiman smps!!
I bet dac magic owners would have wanted one of these a while back when the stock psu s went up in flames.
HighFidelityGuy
14-08-2011, 22:57
Hi David, would you be able to provide some more details on what output voltage and current range you're capable of supplying these in? Thanks. :)
Hi David, would you be able to provide some more details on what output voltage and current range you're capable of supplying these in? Thanks. :)
Up to 22V 1 amp
Any configuration can be catered for, if the current is high the components may be different and price adjusted pro-rata but the basic £100 PSU has been designed with Caiman and Dacmagic in mind.
I have made a 6.6 amp one but it was much higher specification (for a Ripnas Statement).
HighFidelityGuy
15-08-2011, 14:38
Thanks, I'll keep this in mind as I want to swap the SMPS on my router at some point. I'll have to check what it's requirements are though. Cheers.
RochaCullen
15-08-2011, 15:29
Nice one David,
I will definitely be ordering one of these for my Caiman. Just have to wait for next pay day. ;)
Will we be needing to order any special cable to go between Caiman and PSU?
Nathan
In what way are these supplies "better?" Furthermore, are ALL SMPS types to be damned without proof?
Sorry, but funds is tight for many these days and I feel that we need some proper proof in these things :lolsign:
In what way are these supplies "better?" Furthermore, are ALL SMPS types to be damned without proof?
Sorry, but funds is tight for many these days and I feel that we need some proper proof in these things :lolsign:
Which is precisely why I brought this product to market to help replace the wall wart with something better for a reasonable cost. It it was a branded product it would be £295
Just a quick word guys, no discount codes allowed with these please, thanks.
Looks good David, big market for this kind of thing for sure.
Good luck. :)
Hope so, was looking for a better DAC than my current one but does anyone do try before you buy on decent DAC's?
does anyone do try before you buy on decent DAC's?
Dunno, but if you buy it online from anywhere in the EU, the Distance Selling regulations allow you to return it for a full refund within 7 days (or longer if allowed by the sellers T&Cs) regardless.
Hope so, was looking for a better DAC than my current one but does anyone do try before you buy on decent DAC's?
Stans Dac is very good, next I'd say Rega(debatable!) then further up the tree the M2TECH Young DAC at about a grand.
No real need to spend more I hear..
Shame John Westlake's Audiolab Dac never happened...ah well.
Check at your local hifi dealer..sure they would do loan/trial equipment?
(You'd need to pay for it first though!) :)
Shame John Westlake's Audiolab Dac never happened...ah well.
It's on beta ATM. ;)
There are other good dacs out there...
100£ is a reasonable price for a well made PSU.
In what way are these supplies "better?" Furthermore, are ALL SMPS types to be damned without proof?
Sorry, but funds is tight for many these days and I feel that we need some proper proof in these things :lolsign:
No, clearly not, as can be seen by the use of SMPS in kit by Chord and Linn. But I would think the fact that Chord have clearly put a vast amount of effort into their power supply R&D would indicate that the £10 supplies that are included with some products can be improved on.
There is no special magic sauce in the MCRU £100 supplies, its just a EN61558 transformer, 10A Schottky diodes in a bridge, good quality cap (22000uf or 10000uf depending on voltage) and a pair of three pin regulators in a tracking regulator setup with good size heatsinks. Simple and does the job very well. You could build yourself one the same for less, but not that much less.
StanleyB
24-08-2011, 09:31
I have often done my best to point out that price is no indication of quality. So the manufacturing cost of a £10 SMPS unit does not mean that it is an inferior product in any way.
My own TC-7510/TC-7520 SMPS has cost a lot of money to develop, but its low price is mainly based on the cost of the components and assembly. It's only designed for low current application, so it does not have to be big and bulky. At the same time it has been built and certified to the following approvals:
Efficiency
• CEC Level 5
• Energy Star 2.0
Immunity:
• EN55011
• EN60601-1-2
• EN61000-4-2
• EN61000-4-3
• EN 61000-4-4
• EN61000-4-5
• EN61000-4-6
• EN61000-4-8
• EN 61000-4-11
In fact, it is so good, it has now been certified as suitable for medical applications.
I wonder how many power supplies costing a multiple of the cost of my PSU can even pass 25% of the above.
No, clearly not, as can be seen by the use of SMPS in kit by Chord and Linn. But I would think the fact that Chord have clearly put a vast amount of effort into their power supply R&D would indicate that the £10 supplies that are included with some products can be improved on.
There is no special magic sauce in the MCRU £100 supplies, its just a EN61558 transformer, 10A Schottky diodes in a bridge, good quality cap (22000uf or 10000uf depending on voltage) and a pair of three pin regulators in a tracking regulator setup with good size heatsinks. Simple and does the job very well. You could build yourself one the same for less, but not that much less.
Thanks Nick, I promise to moderate my pauper pessimism :punch:
Without wating to get into a war of numbers, the efficiency of a SMPS will always be better than a linear supply, no question about that. Most if (not all) the standards listed there are related to EMI emisions and requirements for use with medical equipment, and are clearly important to the designer of the supply you use, but none relate (other than possibly 61000-4-11) to the audio band noise levels of the DC produced.
But its a free market, people can try (or not) and decide what they prefer.
Thanks Nick, I promise to moderate my pauper pessimism :punch:
Hey, no, its a valid point you raise. Thats why I think the best thing is transparency. Its just engineering at the end of the day.
StanleyB
24-08-2011, 11:38
So which testing standard would you suggest that I use for the audio frequency band then Nick? As fas as I can gather, the overwhelming complaint about SMPS is the high level of RF noise from such designs. That's why we concentrated on that aspect of the design for the external power supply regulation. The medical approval standard was the closest thing we could find that tackled noise that would otherwise filter through into the audio bandwidth.
The efficiency was a required by product for many users, who frequently ask about how expensive it would be to leave a DAC on 24 hours a day. So I have made great efforts to tackle customers concern as far as power supply efficiency and noise performance is concerned. It gets on my nerves therefore when I regularly read about low cost power supplies being crap. Not only is that banding all low cost power supplies in one group, it also gives the impression that customers HAVE to fork out a lot of money on a power supply. I don't buy into that expenditure requirement.
Yep, all valid points Stanley. I hope you see that I haven't said that all such power supplies are crap. But its certainly been my experence that some of them certainly leave a lot to be desired. If nothing else because they emit a audible whine.
I agree, that if I was looking for such a power supply to include in something like your DAC, I would look at ones that meet the same standards you mention.
But in some cases, the reasons that those standards exist are due mainly to use of the type of power supply in question. Assuming even moderate shielding and parts, its unlikely that a linear power supply will generate RF of any kind. If all SMPS were blameless the standard would have never been required.
In this case, there seems to be a demand out there in audio land for replacements for some of the SMPS that are supplied, this design was created in an attempt to cater for that demand at a price that reflected the actual manufacture cost, not some accountants wet dream.
This site is full of threads about people modifying stuff (including your own) and finding improved performance. You yourself, sensibly (IMHO) pay attention to that and encourage that sort of investigation and then it seems, incorporate some of those finding to produce new and better products.
The fact you may regularly read about low cost power supplies being crap, doesn't mean I have said so, you may have a valid argument against those folk, but I don't think I am one of them. You could frame the same argument:
"It gets on my nerves therefore when I regularly read about internal DAC's being crap. Not only is that banding all internal DAC's in one group, it also gives the impression that customers HAVE to fork out a lot of money on a DAC. I don't buy into that expenditure requirement."
Ok, some objective comparisons. 12v MCRU supply and 12v plug top supply of the type that might come with kit. It was the first one I put my hands on, many are better I am sure. Both supplies are being asked to deliver 750ma, both less than 50% of their rated current.
First the Switch mode.
http://www.lurcher.org/~nick/ps/SM1.gif
Then a closer look at each of the spikes from the switch mode, same vertical scale
http://www.lurcher.org/~nick/ps/SM2.gif
Then on the same scale, the £100 linear supply
http://www.lurcher.org/~nick/ps/LN1.gif
Of course if you increase the scale you find the noise from the linear supply, but its at least an order of magnitude less than the switcher.
Reid Malenfant
24-08-2011, 20:31
So what is the transient response like on a step load change? What i mean is assuming a nominal 100mA current delivery if the circuit demands say 500mA all of a sudden what are the scope traces like then?
Continuous current draw doesn't tend to happen as i'm sure you know, so just asking ;)
Continuous current draw doesn't tend to happen as i'm sure you know, so just asking
Neither does instantaneous changes in demand from 100ma to 500ma for that matter. But I will try and capture that response. Will be tomorrow now.
:popcorn: :popcorn:
Marco.
Neither does instantaneous changes in demand from 100ma to 500ma for that matter. But I will try and capture that response. Will be tomorrow now.
It will have to wait till the weekend. the power supply I was measuring before has gone to its new owner. I will get another to prod soon.
BTW, I had a quick look at the power supply that the Squeezebox Touch comes with. I will post some images later, its much better than the first SMPS I tried, but far from blameless, its got 38kHz spikes on its output when its under load.
No worries, Nick. Do update us though, when you get a chance, as I'm following this thread closely :)
Marco.
Nick,
Some nice and smiple easy to follow comparsions there thank you.
Now would that particular unit actually pass the CE directive on conducted emmissions Nick?
Specifically:-
BS EN 55013 : 2001 + A1: 2003 + A2: 2006
BS EN 55020 :2007
BS EN 61000-3-2 2006
BS EN 61000-3-3 2008
BS EN 61000-4-2011
A great many of the audio products currently available I feel would not pass the conducted emmissions, radiated fields, harmonic current emmissions, Immunity to EM field carrier tests, fast transients (iec outlet) etc. Not to mention the ESD testing lol lightening strike anyone ?
For those of us who comply with the regulations and invest a great deal of time and funds into making our products fully certifed CE approved leaves us a little sour
If people understood the complexity and stringency of the directives and the amount of 'hoops' you have to jump through to achieve this you may find quite a few products wanting.
Not to mention the second stage 'Safety testing'
IEC EN 60065G Annex ZB, Annex ZC and A deviations
Everything from a component drop test (where applicable) to the owners manual layout and information, equipment packing even down to the screen printing on the back of the components!
Every single product has to have a build manual, parts list approval noting on EVERY part where possible.
Obviously not all of the divertives apply to all audio products and CD players / Dacs have other directives which apply to them in relation to RFI ingress and radiation.
Anyway, sorry for the ramabling back to my original point Nick, you observations of the SMPS do you feel from your limited measurements you have made so far it would pass a CE approval centre testing procedure?
Tony
Hard to say Tony, what I can say is that both the SMPS I have tested and reported on were bought by me in the UK and they both have CE markings.
And just in case anyone want to know, the MCRU power supply PCB design was done with the EN60065 Limits on creepage and clearance distances and Insulation requirements in mind. Also all the parts used are all approved including the transformer to EN61558, EN60950, UL, C-UL and CE.
Cheers, Nick.
And as far as I'm concerned, with any sales of these PSUs through AoS, that's fine.
Tony, if you have any issues with David or Nick for selling these PSUs, then please take it up with them in private, via PM or email, as I have no wish to host these discussions here, and allow further 'thread crapping' on someone's trade advertisment, which is in conflict with the rules of the site.
Cheers! :cool:
Marco.
Back to business, anyone with a Technics SL1200/1210 and standard platter who does not want to / cannot spend £300+ on an external PSU may want to try one of these as a 21V version is available for use with the Techy, it won't be as good as my £495 one of course but will still improve on the psu inside the deck as we already know removing the existing PSU works wonders anyway.
Back to business, anyone with a Technics SL1200/1210 and standard platter who does not want to / cannot spend £300+ on an external PSU may want to try one of these as a 21V version is available for use with the Techy...
"These" being what exactly? :scratch:
;)
Marco.
Sorry Marco, should have made it clear, the same model of entry level PSU will also power the Techy so for £99.95 you can get an entry level external PSU for your SL1200/1210 with standard stock platter, sorry for any confusion caused.
PM to discuss your requirements or phone me anytime.
No worries, dude - gotcha now! :)
Marco.
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