Toroidal Linear vs Switch Mode Power Supply

[ILYA]

ok, I still haven't purchased the new amps because I'm still stuck on this whole "Toroidal vs SMPS" dilemma... we're talking about a large PA sound system, 8 hornloaded subs, 8 dual-15s and 4 single-15's, running at full blast for 8+ hrs at a time...

built for DJ and EDM music to be played at indoor and outdoor venues, sometimes dirty warehouse power, sometimes huge genset split up through spider boxes, sometimes a nice club with proper wiring, gotta be ready for everything...

the big question (still) is - toroidal vs switching power supplies - and how do they perform under sagging line conditions... there are several schools of thought, some people believe in one technology, some swear by the other technology, and some are on the fence like me and just don't know which way to jump... wouldn't mind lightening up my racks, but don't want to do that at the expense of sound quality or volume...

I realize that amps don't work at 100% duty-cycle at all times, in fact, they don't at most times... however, what happens when there is that 30-second bass drop that the DJ eq'ed up ??? is it better to have a heavy-ass ol-school toroidal transformer that has huge capacitors storing all that current just waiting to be released - OR - is it better to have a light-weight new-age switcher efficiently drawing consistent power from the source ???

any other thoughts on the matter or useful links to other discussions?

[DJPhatman]

... however, what happens when there is that 30-second bass drop that the DJ eq'ed up ??? is it better to have a heavy-ass ol-school toroidal transformer that has huge capacitors storing all that current just waiting to be released - OR - is it better to have a light-weight new-age switcher efficiently drawing consistent power from the source ???

Option 3: use proper limiting, high-pass filters and compression. Over-excursion occurs when the Xmax is exceeded by improper HPF, no or improper limiting, and input voltage spikes. Proper limiting and HPF are a requirement, not an option.

[Rune Bivrin]

I realize that amps don't work at 100% duty-cycle at all times, in fact, they don't at most times... however, what happens when there is that 30-second bass drop that the DJ eq'ed up ??? is it better to have a heavy-ass ol-school toroidal transformer that has huge capacitors storing all that current just waiting to be released - OR - is it better to have a light-weight new-age switcher efficiently drawing consistent power from the source ???

any other thoughts on the matter or useful links to other discussions?

First of all there are no capacitors huge enough to supply power for a 30 second bass drop. The design lets them be refilled 100 or 120 times per second, so that's just not warranted.

Beyound that it's a matter of design goals. There are SMPS-s that are designed to work anywhere in the world and thus will function properly with anything from 80 to 280 volts AC at almost any frequency. With one of those the actual amplifier can be designed for a specific supply voltage using fairly tight tolerances.

An old-school toriodal transformer will always have the output voltage proportional to the input voltage, and thus the amplifier has to be designed to work with a wider range of supply voltages. Or just cut out if the voltage sags and blow if it spikes...

A blanket statement isn't really meaningful, but I'd take the good SMPS any day. Preferrably together with class D amps for increased efficiency leading to fewer tripped breakers.

[ILYA]

thanks for your input guys... so with SMPS, would it be much help to add a voltage regulator (such as TrippLite LCR2400) ??? any recommendations for amps that are known good performers?

[Rune Bivrin]

thanks for your input guys... so with SMPS, would it be much help to add a voltage regulator (such as TrippLite LCR2400) ??? any recommendations for amps that are known good performers?

Totally depends on the SMPS. With a good SMPS a voltage regulator should be completely pointless, as that is part of the SMPS design.

[ILYA]

so how could I tell from looking at the spec's if a power supply is "good" or well-regulated ?

[Rune Bivrin]

Ah, well that's an issue. Without looking at schematics or detailed technical specifications about regulation (that may not be available) you can only guess and go by reputation.

An amp that boasts PFC (Power Factor Correction) is more likely to be well regulated, and also any amp that has a universal voltage (100 - 250 volts) without the need to flip a switch.

One thing to bear in mind is that every computer manufactured since 1981 (the advent of the original IBM PC) has switching power supplies, so it's not like it's bleeding edge technology anymore. No amp needs more stable operating conditions than a computer. The only difference is the computer represents a more static load.