View Full Version : 5v 6 amp too much current for squeezebox?

2008-03-21, 23:03
I am going to buy a medical grade smps for my squeezebox since I heard the stock sb wallwart beats the Bolder modified Elpac power supply. This works if a felix power conditioner is used in the power circuit. Here is the link.

I figure if a cheap smps wallwart can beat a good linear supply than a good smps should be able to beat a high class audiophile linear supply.

2008-03-22, 01:44
As long as the PSU is voltage stable, it should only deliver the required current that the Squeezebox needs. It can only be a problem if the voltage output of the PSU is not stable (5v) at low amp output.

Shouldn't be a problem.

2008-03-22, 17:03
If your PSU can deliver substantially more than the original, you should add a fuse for safety. The original PSU will go into current - limiting if there is, for example, a damaged cable or fault in the unit. A beefier supply may just burn its way through the fault, the wiring, your house etc.

However a SMPS designed to do 6 amps may actually be more noisy if run a long way below its rated load - at some point most supplies will go from a continuous mode to a 'hiccup' or discontinuous mode, which could well produce more audible artifacts and output voltage fluctuation.
'Medical grade' generally only affects earth leakage, and not the level of noise on the output.

2008-03-23, 07:20
the sb3 will draw the current rather than the psu supply it !

2008-03-24, 23:27
Hah! "Medical Grade"! Hah! Hah!


2008-03-28, 06:58
Medical grade powersupplies are great, great filtering, low noise, low rfi/emi emissions and very stable voltages. Unfortunately high prices.

2008-03-28, 07:47
Medical grade powersupplies are great, great filtering, low noise, low rfi/emi emissions and very stable voltages. Unfortunately high prices.

Do you have an example of the actual specs for these figures of a "medical grade" vs a "standard" power supply or are you just assuming that the higher price buys you those things? More importantly, are the improvements in those specs relevant to the sound of your audio system?

I think this is just the old high-end audio myth that says "if it costs more it must be better."


2008-03-28, 09:18
I think this is just the old high-end audio myth that says "if it costs more it must be better."

That's no myth. In fact, it is a direct relationship. A component costing $300 is exactly 3x better than one costing $100.

One time I needed to do an upgrade but the $500 model seemed to cheap to be a worthy upgrade and the $1000 model was too much. I told the guy my budget was somewhere in between. In the end he made some special concessions and let me buy the $500 model for $750. I jumped at the opportunity because it was right at my price point and it sounds so much better than it would have if I'd only paid $500.

2008-03-28, 09:29
If you really want the best, forget "medical grade"- you need to find a military power supply! Everyone knows the military pays absolutely stupid money for everything- remember those $600 toilet seats (imagine how SATISFYING it must have been to use one of those!). If you find a military supply, you know you'll have the best possible supply because the most possible money was spent on it. You can either buy the supply new from the military supplier, in which case you'll get maximum improvement from your audio system, or you can find a surplus unit and get close-but-not-quite the same satisfaction from knowing that at some time in the past the military guys paid a huge price even if you didn't.

Oh yeah, one more thing... the relationship between price and improvement is exponential- that's why the improvements resulting from expensive power cords and audio cables are always described with adjectives like "huge", "day and night", "tremendous", "resplendent", etc.


2008-03-28, 12:29
You need to understand what "Medical Grade" really means. I am an EE who designs medical systems. It means it was built to, and passes, a series of standards set forth by testing agencies (like UL). It has to do with safety, and in some cases reliability. Yes it is somewhat true that medical grade supplies may have better specifications for ripple, noise, etc., but that is not always true. It is highly dependent on the manufacturer and type of supply. In general a linear is better for audio applications than a switcher (less noise), but is less efficient. A wall wart may or may not be better or worse depending on how its built. Given the exact same specification, for audio I would take a linear wallwart. But just because it says medical grade, doesn't make it better. In fact gievn 2 supplies, 1 medical one not with the same specifications, I'll take the cheaper one. The key is Identical specifications! And thats not usually the case.
The whole idea of an external supply is to supply the unit with the cleanest, most robust DC power available, without having AC noise within the system.