Class D 4 channel

[Haunz 10+ year member]

^ I actually found that first link last night squeak.... Interesting stuff !

Pretty pimp of O&B and Dr. Nielsen to post those papers online.... I have not had a chance to read any of them in depth (would take a few hrs at least); but at first glance it seems that instead of using a carrier wave at a single frequency to switch the outputs these amps use a variable frequency and a unique feedback method to increase bandwidth and minimize high frequency switching noise...

I don't quite understand how the carrier waves are generated yet; but its clear they don't use a clock generator as conventional class D amps do...

 

[DARKHART 10+ year member]

i got the 100,000 mile bumper to bumper warranty with it and if by putting a new alt in meant bye bye warranty my wife, and myself, would kill me, heehe..
eddie

Just a little FYI , even if there was an HO made for your car, you would not lose your warranty....the Magnunson-Moss Warranty Act protects you from losing your warranty...the only way you'd lose it is if the HO was the cause of damage to your car and then the dealer would have to prove how it damaged the car......//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[efm80 10+ year member]

Just a little FYI , even if there was an HO made for your car, you would not lose your warranty....the Magnunson-Moss Warranty Act protects you from losing your warranty...the only way you'd lose it is if the HO was the cause of damage to your car and then the dealer would have to prove how it damaged the car......//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

really!!??? thats good to know. few questions, do you know where it states that in the Warranty act?? also do you think doing the BIG 3 or adding lots of amplifiers and equipment would void the warranty??

thanks

eddie

 

[bass_lover1 10+ year member]

really!!??? thats good to know. few questions, do you know where it states that in the Warranty act?? also do you think doing the BIG 3 or adding lots of amplifiers and equipment would void the warranty??thanks

eddie

Thats the whole premise of the act is to keep dealers from denying warranty work if there are after market parts installed. Like, if you install a lowering suspension and you blow a shock it probably wouldn't be covered, but if you install a suspension and blow the motor, the two aren't related and you'll be covered.

 

[DARKHART 10+ year member]

Thats the whole premise of the act is to keep dealers from denying warranty work if there are after market parts installed. Like, if you install a lowering suspension and you blow a shock it probably wouldn't be covered, but if you install a suspension and blow the motor, the two aren't related and you'll be covered.

Exactly....and some dealerships will try to get over on you because they know that most consumers have never even heard of the MMWA.......//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[FoxPro5 5,000+ posts]

Eclipse has been using ICE modules in their amps for at least 6 years, probably longer.

There is nothing special about amp topology and the ultimate sound you're going to get. I can change the sound of my amp considerably by moving my head 3". //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[eharri3 10+ year member]

IVe been running an Eclipse EA4200 for 6 months now. About the same power as my old MTX, but maybe 60% as big, and sounds better.

 

[helotaxi 5,000+ posts]

Sounds like ICE is a similar approach as the Tripath. Variable switching rate depending on the signal. The JL HD amps use a different technology still and the Memphis S-class (not an amplifier topology, just their model designation) are out there as well.

 

[Haunz 10+ year member]

Sounds like ICE is a similar approach as the Tripath. Variable switching rate depending on the signal. The JL HD amps use a different technology still and the Memphis S-class (not an amplifier topology, just their model designation) are out there as well.

Tripath actually takes the input signal and generates high frequency noise using some fancey mathmatical algorithums to switch the outputs...

it's quite a different way to skin the same cat....

I have not looked into the JL HD amps ?!

 

[helotaxi 5,000+ posts]

Variable rate switching either way though. That's what I was getting at.

 

[Ed Lester 10+ year member]

I havent read through this whole thread but what is the general opinion on full range Class D amps?

Do they make any FM signal interference?

Any high pitched whine in the signal?

What about SQ?

 

[helotaxi 5,000+ posts]

The newer ones have pretty much solved the problems that plagued the early designs. Full range Class D's are a lot more common than people think. The amount of current saved compared to a Class A/B isn't all that much on mids and highs (hardly enough to warrant the change, IMO) BUT because they don't waste much power, they can be really small. The size advantage is the one that has my attention, not that I'm planning to replace my brand new Sundowns any time soon, but for the future...

 

[Ed Lester 10+ year member]

The newer ones have pretty much solved the problems that plagued the early designs. Full range Class D's are a lot more common than people think. The amount of current saved compared to a Class A/B isn't all that much on mids and highs (hardly enough to warrant the change, IMO) BUT because they don't waste much power, they can be really small. The size advantage is the one that has my attention, not that I'm planning to replace my brand new Sundowns any time soon, but for the future...

Yeah, I've seen the new Arc Audio amps. They can fit in the palm of your hand and still make good power for mids and tweets.

The past few years I have focused more on sub amps so I am just remembering how noisy class D can be in the upper frequencies.

I think it is worth it to take a listen and do comparisons.

 

[helotaxi 5,000+ posts]

The new Arc amps aren't even Class D. They're Class G or H, I can't remember which. TOuput stage is Class A or A/B but the power supply varies the rail voltage so there is minimal voltage drop across the output devices and thus very little wasted power. The result is that it is actually a linear amp, which switching amps aren't, with the efficiency of a switchmode amp. The greatly increased efficiency means that there is little need for a heatsink because it just doesn't get hot. Same topology that the old Blade Audio SE series amps used in the early 90's if you remember those. They were able to fit a pretty powerful amp in a tiny foot print. They WERE expensive though. Probably why they didn't last as a company. Just couldn't move enough of them.

 

[Ed Lester 10+ year member]

The new Arc amps aren't even Class D. They're Class G or H, I can't remember which. TOuput stage is Class A or A/B but the power supply varies the rail voltage so there is minimal voltage drop across the output devices and thus very little wasted power. The result is that it is actually a linear amp, which switching amps aren't, with the efficiency of a switchmode amp. The greatly increased efficiency means that there is little need for a heatsink because it just doesn't get hot. Same topology that the old Blade Audio SE series amps used in the early 90's if you remember those. They were able to fit a pretty powerful amp in a tiny foot print. They WERE expensive though. Probably why they didn't last as a company. Just couldn't move enough of them.

I remember Blade.

From what I heard they also made black boxes for the Aerospace industry and had firmware in the amps that can tell the factory how long you used the amp, how many times it went into clipping, how often you used an ohm load too low, etc... everything you need to know for warranty purposes.

I heard they stopped making amps to concentrate on their real money maker in aerospace.