Confused by ICE applications

11-04-08: Wonderful_electric
Is it just me or Icepower amps...sound more hyper-detailed than graceful and relaxed.
Wonderful_electric (Answers)

It's not just you. I completely agree.

Just took delivery of an International Recitifier AUDAMP7S stereo half-bridge class 'd' amp.
I'll be trying to build a battery operated 2nd system with it.
Unfortunately, it has NO built in PS, so it is either battery of +-55v or so....or the hardway of a conventional or SMPS.
There are NO 'exotic' parts....caps and resistors all appear to be off-the-shelf.
I wish I could post a picture!
Kijanki, I don't know if I mentioned this before, but I WORK for IR, in the 'fab' making power and other semiconductor devices. I have spoken to the design guys and they will eventually make a house call to listen to there stuff in a Magnepan system.
The voicing of these amps was not a major concern though many panel type listening tests were conducted.

Magfan - I know the IR amp - whole project with schematics and PCB was available on their web site. I like SMPS if designed right. They are regulated and work on non-audible frequency that is easy to filter out (not to mention efficiency). Layout for switching power supply is not a trivial thing and requires detail knowledge of chip's operation. SMPS are also much stronger for the size since 2" toroid at 100kHz can deliver as much power as 10" toroid at 60Hz. Unfortunately designers try to save money and often undersize SMPS.

Half bridge class D amps like your IR or Hypex sound like very good SS amp while full bridge (Icepower) sounds a little toward good tube amp (DIY forum). Full bridge also carries DC equal to half of supply voltage on speaker cables (relative to ground).

If you build your own standard power supply investigate "slit foil" electrolytic capacitors (used in Hypex kits) - very expensive but fast. Cuts in foil break induced currents and lower effective inductance.

Let me know how you like it when you fire it up. Icepower patent is just one of many variations on Sigma-Delta A/D.

Class D without sigma-delta modulator was only good enough for guitar amps since Mosfets were slow and just in recent years Mosfets got much faster (carrier moved to 0.5MHz or better).

Yep, been in touch w/designer. He had to tell me about the 'bridge' switch.....basically 2x juice MONO! Can you spell 's u b a m p'??
My first (guess / intent / urge) is to go with 4x12 gel cells for each rail....This will give REAL clean low ripple power and allow me to hear it at its best and perhaps also allow the sound of various power supplies and associated components to be fairly evaluated.
I suspect that with appropriate hi-sensitivity speakers, no need will ever apparent for more than 2x20 watts....which with appropriate speakers will drive you out of the room. 5amp hour batteries will provide 60 watt hours so should be enough for several hours of LOUD listening. Actually, 50v at 5amps is 250 watts, x2 rails.....well, you can do the math! I'm just confusing myself.
Believe me, I've read the Hypex / ColdPower stuff avidly. This is what got me started on this kick in the 1st place.
I was even thinking of springing for a HYPEX power supply and the 180 transformer. Should 'bout do it?
If I could post a picture....can you post here? I'd setup the macro and get out the AlienBees (lots 'o light, trust me) and take a few pics.
My buddy at IR is pretty helpful and one day I'll have him over for a listen and some Single Malt.
My PSAudio GCC250 really likes the Maggies.....it should be a fun comparo:

It is much better than few hours. Typical average power is only in order of few percent of maximum power and your 60 watt hours battery might give you 20 hrs playtime. Why don't you connect permanently slow/trickle charger. It will recharge over night and during usage won't be "visible" because of extremely low impedance of battery. Be carefull and wear glasses since you're dealing with batteries (no current limit).

2x juice mono is nice when you bridge half-bridges but people often forget that it quadruples power while power supply is only doubled - good for high peaks though.

As for speakers sensitivity - distance is even more important because sensitivity will get you only around 3dB (twice power) while half distance to speaker is 6dB (4x power). Maggies are not the point source and it might drop much slower with a distance but they are not beating sensitivity records.

I've heard a lot of good things about maggies but boy - are they huge!
20W is not bad because it is only half of the 200W loudness.

Avoid 180W (smallest) Hypex - even Channel Island D100 uses larger one (same as D200 at lower voltage). Look at D100 construction - very nice design. Monoblocks in small u-shaped chassis with torroidal transformer attached to front wall. They use a lot of small caps to drop ESR.

Somebody mentioned that they (Channel Island) modify Hypex but I don't know how. We are still on the subject of this thread but it gets more technical than perhaps Macdonj had in mind.