For technical people

Everything in life is a compromise. Chord have developed similar technology for using fast switching power supplies. I believe it's similar logical technology to that used in power supplies for PCs.

As for benefits, well obviously Chord and Linn think there are some, whereas other manufacturers believe that it causes compromises elsewhere.

Frankly I wouldn't worry about the technology that's in your hi-fi. Just listen to it. If it sounds good, it is good.

Linn use what would normally be known as switching power supplies (switch-mode power supply, or SMPS).

These are used almost everywhere today, as they offer very high powers, from much smaller more efficient and cooler-running units. I won't go into the details of why here, but a web-search for SMPS + efficiency will probably get you all you need to know.

Other potential advantages are that because the energy in the PSU reservoir capacitors is being replaced more quickly, and at a frequency above audio (usually) they can cope with musical power demands much better.

The downside is they are all noisy - Linn claim to be able to make them quieter than conventional supplies, to which my response is their linear supply designs must be very poor indeed!

They are much harder to design, and also tend to radiate electro-magnetic interference unless well screened and designed.

Frankly there is no way on earth you can make an SMPS PSU quieter than an optimal linear supply, without degrading most of the benefits of SMPS in the first place.

They do have very real benefits that make them worthy of consideration - maybe when followed by a high quality linear supply.

Additionally they need mains input filtering to comply with EMC regulations, and Naim systems don't like these filters on the same mains sockets as the system.

Six of one, half dozen of the other...

Andy.

As with a great many things electronic, it is the implementation, not the ideology. A good idea poorly implemented is a "mistake"!

I beleive Andrew pointed out in another post regarding circuits in naim amps that the devil is in the details.

There's still no magic bullet.

Also, switching PSUs have the nasty habit of launching a whole lot of nasty harmonics on the mains side.

The DC going to the device's internals might (and that's a big if) be clean but the rest your system will have deal with the pollution.

Also, if your utility's power isn't very stable frequency wise, the switching PSU's high frequency will have to compensate... can anybody say FM source ?

For kicks, plug and fire a desktop computer (even with a top notch PSU) on your wiremold power bar

Martin

PS: First post, woopee

Salut Martin,
Welcome to the Forum.

Emmanuel

All opinions are my own, and reflect those of the organisation i work for, even if not stipulated.

quote:

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Originally posted by Andrew L. Weekes:
Linn use what would normally be known as switching power supplies (switch-mode power supply, or SMPS).

These are used almost everywhere today, as they offer very high powers, from much smaller more efficient and cooler-running units. I won't go into the details of why here, but a web-search for SMPS + efficiency will probably get you all you need to know.

Other potential advantages are that because the energy in the PSU reservoir capacitors is being replaced more quickly, and at a frequency above audio (usually) they can cope with musical power demands much better.

The downside is they are all noisy - Linn claim to be able to make them quieter than conventional supplies, to which my response is their linear supply designs must be very poor indeed!

They are much harder to design, and also tend to radiate electro-magnetic interference unless well screened and designed.

Frankly there is no way on earth you can make an SMPS PSU quieter than an optimal linear supply, without degrading most of the benefits of SMPS in the first place.

They do have very real benefits that make them worthy of consideration - maybe when followed by a high quality linear supply.

Additionally they need mains input filtering to comply with EMC regulations, and Naim systems don't like these filters on the same mains sockets as the system.

Six of one, half dozen of the other...

Andy.

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Thank god there are people on this site like you Andy....With something important to say. If I get banned so what...but this site is going down bank. Regards, to them that actually have something interesting to say.
Regards, to them that matter.

Hi-Fi a means to an end.

For those of a technical persausion, the application note below provides a vast array of very useful information about switching power supplies and noise reduction.

http://www.linear.com/pdf/an70.pdf

Cool cartoon on the last page...

Andy.