what's the difference between SMPS and toroid +supply HG

[terteliu]

I've looked alot on hypex web site and I see that there are two posibilities to power 2 Ucd 180

first by using 1 Transformer TR180 (toroidal) + UcD supply HG - about 250 euros both
second by using 1 SMPS400A180 (it also is enough for 2ucd180) - about 140 euro


What is the difference between them?

I'm looking for 0 noise (heard not measured) when the amplyfier is powered up and volumed up to let's say 1 watt. My Technics su-vx720 has an anoying little noise, when nothing is playing.

Also I'd like a more portable amplyfier, something smaller, and SMPS400A180, is smaller, than the toroid and Hg supply, so does it worth to pay "almost" double, and make a bigger case?

[stratus46]

Originally Posted by terteliu

I've looked alot on hypex web site and I see that there are two posibilities to power 2 Ucd 180

first by using 1 Transformer TR180 (toroidal) + UcD supply HG - about 250 euros both
second by using 1 SMPS400A180 (it also is enough for 2ucd180) - about 140 euro


What is the difference between them?

I'm looking for 0 noise (heard not measured) when the amplyfier is powered up and volumed up to let's say 1 watt. My Technics su-vx720 has an anoying little noise, when nothing is playing.

Also I'd like a more portable amplyfier, something smaller, and SMPS400A180, is smaller, than the toroid and Hg supply, so does it worth to pay "almost" double, and make a bigger case?

The toroid supply is a linear supply that uses a toroidal rather that E/I core transformer. It is comparatively large and inefficient relative to the switcher but not at all a problem. The switcher might include power factor correction and be 'universal' meaning 90-250 Volts and 50/60Hz without any user selections. The linear supply won't do that but likely includes manual 120/240 switching. DON'T RUN 240 INTO 120 as it often destroys the transformer. You're more likely to run into high frequency noise with the switcher but it can usually be solved.

G²

[terteliu]

I see that the TR180 has 3 secondarys:

2 - 30V
1 - 13v

The Hg supply has a 12V auxiliary imput, but I don't know what's the curent in it. How much power VA should have the transformer on this output? I wouldn't like to destroy the amplifyer.
The rest till 160VA will be split into half to the other 2 secondarys. I'm going to get a custom made toroidal transformer at a company specialized in this, the price is about 25 euro.

By using a HG supply and a transformer, will the sistem make a sound at startup, like a big buff? Does it need a delayed start?

[toprepairman]

Analogue power supplies (toroid etc) are much more reliable, likely to last a long time.
All SMPS's are time bombs, they will ALL blow up eventually, anything from 2 to 20 years.

[terteliu]

Just now I've seen that the secondary is AC not DC , but it's ok, I'm collecting data

[Javin5]

Originally Posted by terteliu

By using a HG supply and a transformer, will the sistem make a sound at startup, like a big buff? Does it need a delayed start?

No sound, no thump, neither when switching the amp on or off. This is my experience with a HG supply and UcD180. And in my system, there is no hiss or hum, even if I put my ear close to the speaker. If you hear anything, it comes from your preamp.

[thejohn]

I've only tried UCD400 with SMPS400 and this has probably the least background noise of any amp I've ever owned! Powering it up the first time I thought it was broken.... no thurn on noise, no hiss, nothing. This is with Altec 604s, 4Pi's and my 15" Tannoys - all 97-100dB/w/m.... Very impressive!

If the SMPS is a timebomb, then I guess the amp is too since it's made of the same stuff! I can live with that!

[ssanmor]

All SMPS's are time bombs, they will ALL blow up eventually, anything from 2 to 20 years.

Are linear PSUs with their semiconductors and electrolytic capacitors eternal and I didn't know?

Todays' well designed SMPS have a very, very low MTBF, so in my opinion this is no longer a factor, not to speak about other obvious advantages, lower noise in the audio output among them.

[goosewing]

Originally Posted by ssanmor

Todays' well designed SMPS have a very, very low MTBF, so in my opinion this is no longer a factor, .

That would be higher MTBF we might hope.

[ssanmor]

Oooops! of course. Thanks!