Axiom Home Page Forums General Discussion The Water Cooler Who reviews the reviewers in the Audio Industry?

Rich, regarding SMPS vs. LPS, I have a 1000-8 coming that will be used with my actives. That amp is spec'd to give me 375 dynamic Watts on all eight channels simultaneously into 4 Ohm loads from a 120VAC/15A outlet. Show me an amplifier with an SMPS that can do that. Heck, show me an amp that can do that!

Mojo, are you telling me it is impossible to design a switching supply to be as good as the supply in a ada1000?

It is impossible to design a switching power supply that will result in 3000 dynamic Watts from a 120VAC/15A outlet.

Not if you add a flux capacitor, it isn't.

1.21 jiggawatts with that puppy!

Craig, normal caps would probably do the trick ... no time travel needs to be invoked

Nope. Compared to LPSs, SMPSs give you high continuous power with high efficiency in a small package but no dynamic headroom.

Rich - What is this "need" stuff? We aren't commies. We do want stuff!

Dynamic power comes from a combination of higher rails and a bit of storage

To measure continuous power, you apply a continuous voltage and increase its level until clipping is observed into a known load. Say you apply 2Vrms into a 4 Ohm resistive load and observe clipping. That's a total of 1W continuous power (2*2/4).

To measure dynamic power, you apply a transient voltage into the same load. Say you apply 4Vrms for 10 cycles and observe clipping in the last 3 cycles. You could then say the dynamic power is 4W (4*4/4) for 7 cycles. If those cycles you applied was a 60Hz mid-bass, you could say the dynamic power is 4W for 117msec (16.7 msec/cycle * 7 cycles). More accurately, I would say I can support 4W into a 4 Ohm resistive load for seven, 60Hz cycles.

1W of this dynamic power comes from the wall socket and the remainder from charge in the storage capacitors.

In this example, the dynamic headroom is 10log(4/1)=6dB. That's a damned impressive LPS!

I would also keep the power supply voltage fixed at say 120VAC for all tests.