IcePower module

if it's anything like synchronous buck converter design at hundreds of watts potential losses in the gate drivers probably can be significant, too.

One of my PCs has a mobo with some questionable part choices it has gate driver MOSFETs that melt down sometimes, not the output FETs.

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** The Ice Power module, with accompanying pre-amp draws 14W at idle and there is no change with 1W output.

At full output(330W) the power draw is 365W.

The famous Ampeg SVT tube bass head from the 1970s draws 170W at idle, with also no change at 1W since it operates in class AB.

At full output(300W) the power draw is 550W.

So played quietly, the class D amp wins hands down.

At full power, the difference is not nearly so huge.

Interesting.

BTW: the weights

IcePower amp: 3 pounds.

Ampeg SVT: a backbreaking 85 pounds

.... Phil

bring a 50 watt tube amp instead and set a crossover so everything above ~150 Hz goes through the tube amp and put the low end thru a subharmonic synthesizer into a subwoofer driven by the IcePower.

Serious bass:

Get a big f*ck-off sub and power it with the IcePower module. Put the signal from your turntable thru about 50ms of delay line and then EQ it into three bands, low, mid, high. Put a stereo compressor on the mid band and the high band. Adjust mid-band compression and EQ to taste. EQ the main signal's low end down a bit but first pick off and sum the low band signal to mono and put it through a dbx subharmoonic synthesizer:

and then into a third compressor, where its side-chain is driven from a band-pass filter isolating the kick drum frequencies, coming from the main signal before the delay, for look-ahead compression on the sub-bass. Then into the sub. Drive the sidechain of the high-end compressor with the kick signal too, to make it "pump" a little bit as well. Then put the highs through a harmonic exciter.

This is how you become awesome-sound DJ.

With such low weight, it makes sense to integrate it into a subwoofer enclosure. While small, low cutoff frequency boxes will have a low efficiency requiring a lot of power that IceCube has sufficient power to drive hard a big speaker element and still make an easily transportable box.

In an instrument amplifier, you could set the crossover even higher, but of course 150 Hz sounds good for a single subwoofer in a stereo or in a 5.1 system.

Are those guitars really usable in a band or just as novelty solo instrument ?

snipped-for-privacy@downunder.com

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** The Icepower module itself weighs less than 1 pound.

But there is a problem - it needs a small fan to keep it cool when running at high power. See spec sheet, it makes the need fairly clear.

The mini bass amp incorporates a thermistor, screwed onto the heatsink of the Class D stage - it starts a 40mm DC fan running when 50C is reached.

I have also had dealings with some 1kW rated Icepower modules ( type 1000ASP ) that were used in a pro-audio sub cab. They were bolted onto a large, flat, finned heatsink that was exposed to outside air.

FYI:

here is a link to the bass amp:

.... Phil

That's typ, 100 max, and multiply that by up to 2x when the junctions are hot.

The idea behind TO-220 FETs with 5x lower Ron and good thermal tab conduction, is a small heat sink, and no fan or forced air.

--
 Thanks, 
    - Win

It can make 600 watts, and I need 120. I think it will work.

I have plenty of other issues to deal with, so a done amplifier chip is great.

I need an overall fan for the rackmount box, so properly locating the inlet holes puts cooling where it does the most good.

I think I'll put the TI chip on the bottom of the board, with a modest heat sink. Holes in the floor of the box will blow incoming air into the heat sink fins or pins. That leaves room in the top of the small board for parts. Manufacturing says they won't mind doing that. I can add a test point per pin on the TI chip, so I can scope it from the top.

In some extreme future application, we could stack a fan over (actually under) the heat sink; I'll plan for that to be possible.

It's always tempting to design things, but the sensible decision is usually to not design things.

Inductors. And maybe some ESR loss in the big caps.

Sure.

Nope, that's the idea of class D - no heat.

Think of it like the light switch on the wall. Power is the product of volt age and current right ? When it is on there is current but no voltage, ther efore zero product. If it is off there is voltage but no current so no prod uct. It's the in between that makes the heat.

have a big heat sink and forced air flow.

Nothing wrong with that but the cost. Any heat is developed during the swit ching period. The faster it switches the more efficient.

Some semiconductors the switching speed degrades with heat, which will then make more heat which will degrade it further. Like thermal runaway in a re gular amp.

In a regular amp you have to heat sink because that is how it is, and you h ave to have the bias track it with temperature. No matter how good a transi stor you use the limit for wattage is thermal. Like I could MJ15024 and 023 for a 25 watt per channel amp. Temperature mainly depends on that heat sin k. The strong or weak transistor will fail at a certain temperature and it won't be that much different, they all derate to zero Pd at some point. And THE preeminent factor in the temperature is the power versus the surface a rea of the heat sink.

And those transistor that are rated like 250 watts Pd ? Sure they can if yo

.

Bottom line though if you use fast enough transistors you should be able to get away with just using the copper on the board for heat sinking. That's what Icepower does.

Well 12 will carry 30 amps, 14 - 25 and 16 - 18.

I'm pretty sure that is just an expensive novelty. 5, 6, 7 string basses are pretty common but AFAIK you generally don't get more than 1 extra low string (B below the 41 Hz low E on a bass guitar) and the rest go on the top.

The lowest strings on that one are like guy-wires. They just flap around mostly by the look of it

The Chapman Stick is a more practical invention if you wanna get into many-stringed instruments.

$2500 for a base model, new, not cheap but not ridiculously priced as far as pro instruments go.

The real bass is

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-TV