Power Adapters

[Nightcleaner]

You know the power Adapters you buy for or get with your gadgets?
I Want a replacement 9volt adaptor For an SMSL M8 Dac. What I want to know is two things.

1. If I buy a 9volt power adaptor on ebay. Do 9volt power adaptors all have the same end fitting into The Device , (Do all Say 9 volt devices have the same Standard adaptor fitting)

2. I appreciate you can buy adaptors with adjustable outputs and an multi-choice assortment of adaptor fittings. But which should you buy for your device an adjustable output or dedicated output. What are the cons and pros?

[Buenchico]

When buying a mains adapter there are six things you need to consider:
1. The output voltage (obviously);
2. Whether the output is AC or DC. (DC is the norm for low-voltage devices) ;
3. Whether the output is 'stabilised' or 'unstabilised'. (Unstabilised power supplies can produce voltages far higher than the ones specified on the box if the 'load' doesn't match what the designer expected the adapter to be used with ;
4. The maximum current which the adapter can provide. (It needs to be as great as that required by the device which it's to be used with; it won't matter if it's higher but the adapter could overheat, burn out or actually catch fire if it's lower) ;
5. The size of the 'tip' (= 'plug') which connects to the device it's going to be used with ; and
6. Assuming that it's DC, the polarity of that tip. (Some devices require a 'centre positive' tip; others require a 'centre negative one').

[Nightcleaner]

Thanks for that great response.

[Buenchico]

^^^ Further to the above, look at the power input socket on your SMSL device to see whether the power needs to be AC or DC:
http://www.harmonycentral.com/forum/filedata/fetch?id=31129563&d=1398382724

Assuming that it's DC, also check the tip polarity:
http://www.harmonycentral.com/forum/filedata/fetch?id=31129564&d=1398382724

Then check to see the required current shown (probably measured in mA).

If the information isn't shown on the device, look at the old power adapter (if you've got it) to check whether the output is AC or DC, the polarity (for a DC output) and the maximum output current

Then (unless you can be sure that a particular adapter will definitely match your device) purchase a STABILISED power adapter that can provide 9V (DC, or AC, as appropriate). It's irrelevant as to whether or not it allows you to choose other voltages but it MUST provide an output current which is AT LEAST as high as that specified on the device input (or for the output of the old adapter).

Check also that the TIP POLARITY is correct (or that there's a switch which allows you to opt for the correct one).

Lastly go for a 'MULTI-TIP' adaptor [unless you can be sure that a 'single tip' adapter will definitely match your device].

[Buenchico]

PS: Alternative terms for 'stabilised' and 'unstabilised' (which you might find in product descriptions) are 'regulated' and 'unregulated', respectively.

[Nightcleaner]

Thanks for all that input : To amplify what your saying i looked at power adapters in Argos stores. The buyers reviews were very interesting.

http://www.argos.co.uk/product/9829701

[Nightcleaner]

I tried the SMSL with a borrowed power adapter and the Sml comes on lights up then goes off again . it does this each time you plug and unplug it

Interesting. What do you suppose is going on?

[Buenchico]

^^^ That possibly suggests that the power adapter you've borrowed can't provide sufficient current.

[Nightcleaner]

No better than that after some minor tinkering around. you know know voltage adjustment wheel with an arrow that You put your screw driver in to turn. Well What i did was put the arrow between the lesser voltage and the 9 volt and hey presto we have life.


Here is the device Im not trying to sell it to you ok But This device was tested with some very high end unaffordable Hi Fi for most and the author of the findings could not hear and defined anyone to tell the difference with a high end Dac costing much much more. Sorry I cant put the moral of this story into words :)

[Nightcleaner]

False alarm the device lights up but thats about all as you say it needs the proper power supply or a dedicated power supply 9v 0/P. DC 9v - 1.3A
--

[Buenchico]

1.3A is above the power output of most 9V mains adapters. They typically provide a maximum current of around 0.4A. Anything that can supply 1.3A won't be cheap!