What is a 'Switch mode' amp

Hi whats the different between 'Switch Mode' amps and normal amps. The switch mode amps seem to be a lot lighter than the normal ones please explain.

Hehe, nice to see you here Barry. The answer is of course that switch modes blow up quicker
As you know it's all about the power supply, however a technical explanation of the digital transformer (if thas right) would be nice...
Any takers?

Switch mode power supplies simply get rid of the great lump that is the power transformer and replace it with a much smaller transformer that is working at higher frequency usually in the hundreds of kilohertz region. This allows for incredible small size making great weight savings. All the other components are there for frequency generation, filtering etc.

You will be viewing this post on a computer fitted with a Switch-Mode power supply.
There is absolutely no reason why a switch mode supply amp should not have the reliability of a normal type and there are definite advantages to be had with regards performance as a switch mode can be made that is incredibly stiff with regards rail voltage/output power.

Tony

One more comment to add. Switch mode amps have been out for years, but in the early days they had a bad name. not for unreliability, but for lack of bass. I think that on the professional level, Carver were the first amps that I was aware of.
I'm pretty sure Clair Bros, run with them, and I seem to remember that they had been modified and had external transformers attached to them. Don't ask me how that worked. I only know this because of my involvement with the Who. Clair Bros. did the PA for many years.

I first saw Carvers in Abra's hire stock (Twickenham), they were very thin on the bottom end.
Not sure the reliabilty has been ironed out though? Thomman ones are cheap I know but there have been issues. Reading the posts on SP, also seeing first hand via Tim (Bespoke)
there were some issues with the earlier Matrix renditions. Powersoft do it well, but at what price? Seems to me the costs invloved in making them (see Matrix price hikes since SM)
means there are very few decent budget models.
Unless you know better?

Regarding budget models, If you were as old as me, you would realize that all amps are budget prices. Years ago, when I was involved with Mike Harrison from H.H. He proudly announced that for the first time he was making amps that were £1.00 per watt. This at the time was an achievement. Power, these days has never been so cheap. I guess whatever the price, someone always wants it cheaper.
If you want an amp that's made in England with all the bells and whistles, you will have to pay. Digital amps in spite of not having a large expensive transformer do seem more expensive to produce, although over the years I have noticed the prices dropping, as manufacturers have got to grips with production and the numbers have moved up.

Don't make the mistake of thinking Digital and Switch-mode are the same thing. You can use an analogue amp with a switch-mode supply just the same as a digital amp with conventional power supply.

Budget switch-mode amplifiers with conventional class AB or class H (G) output stages are only just hitting the market, see Behringer EPX range or Thomann TSA range.
Their efficiency/reliability is still to be proven.

That there will be amplifiers with badly designed or underpowered SM supplies out there I have no doubt just as now you can buy a conventional amp with too small a transformer i.e. Berry EP2500 with a 1200va tranny.

For whatever the reason you are definitely seeing the swan-song of conventional power supplies and I foresee within 10 years and may be even less 95% of all amplifiers will be SM. The future for Digital amp's is I think a lot less certain.

Tony

@Nick The price hike with Matrix SM amps has a lot to do with the fact that the conventional ones were seriously under-priced. The low price was in fact to help re-introduce the brand and perhaps to earn some revenue for R&D on the new models.

A 5000va toroidal transformer is still a very expensive component even if you have the facility to wind your own as Matrix do. The SM in the XP5000 is 8Kva, I would dread to think of the cost of that in the old style smiley1 .

Yes, same with everything except houses and fuel, we get it cheap nowadays.
Interesting on the Matrix pricing.
Hopefully the switch over (no pun intended) to switch mode will release a lot of good s/h old style stuff onto the market.

the carvers are not switch mode amplifiers.

Tony Wilkes wrote: The SM in the XP5000 is 8Kva, I would dread to think of the cost of that in the old style smiley1 .

where are these supplies made?