Actually, the eAR has crappy frequency response, and if you look at the specs you'll see that. Let's try not to get personal, OK? Did you actually LOOK at the specs? Is frequency response also not important?

I realize harmonic distortion in small doses is even interpreted as sounding good by some wonks, but I'll take mine without, thanks. If I want some harmonic distortion then the amp is a stupid place to get it - I'll build/buy an adjustable source and put it inline. Maybe I can buy a high-end cable to do that for me.....

So we have a relativly expensive amp with frequency response that varies relatively wildly with load, and somehow this is cutting edge? And the compelling benefit is... ?

Sure, measurements aren't everything, but as a STARTING POINT an amp should measure well - blind listening should take it from there. Harmon International for one (Proceed, Mark Levenson, Lexicon, etc) uses blind listening tests, ABX specifically, but they also use test instruments.

As for dismissing these products out of hand, that is far from the truth. I'm impatiently awaiting the time when someone, somewhere delivers on the promise of the digital amp - high output, low heat, low cost, low distorion, etc. but no one seems to be there yet.

The eAR power module (your B&O link) looks well suited to a powered speaker, where the engineering team has control of the load, but it looks like the low pass filter is still causing some grief for the general case. Do you understand the issue? There's no shame in saying no.

Charlie


[This message has been edited by charlie (edited August 13, 2002).]

I´m not ashamed to admit that I probably don´t understand the issue.
Are you referring to this frequency response? http://www.medicom.bang-olufsen.com/sw1038.asp If not, feel free to point me in the right direction.
If you are, is the " crappyness " because of the fact that the response:
1. - is down 1 dB @ 20kHz or
2. - that it varies with load 0 to -3 dB @ 50kHz or
3. - that it´s down 10 dB @ 200kHz, or is it something else here that I´m missing?
If it happens to be 1., then I truly don´t understand the issue and only your dog could possibly have an opinion about the other two points.

Basicly, yes, while the response driving a resistor is good for a 15 year old CD player or outstanding for a loudspeaker, it's pretty poor compared to competitive products. The vast majority (me for sure) would never notice, and it would be tough (but probably possible) to detect the aberation in an ABX, but why should anyone accept this at all?

So the points are two:

(1) Driving a resistor is easy (as you pointed out) but this amp has problems with it. Will driving a reactive load improve things?

(2) Where is the compelling advantage that would make a person shell out $2000 for this amp?


Charlie

Part of my problem here is why anyone should be bothered with something they couldn´t hear in the first place. On the contrary, A/B class transistor power amps reach their " good measuring " ( low THD ) by being designed with big amounts of feedback, witch in turn create a " dull " sound becase of TIM distortion amongst other things. You could design around it, but to a much higher cost. That´s why a Krell is a Krell and Rotel is, in the end, just a mid - fi Rotel.

(1) This amp has no problems, what so ever, driving any load within it´s designlimits, resistive, capacitive or inductive. This is the point of the concept. If it doesn´t get the power it needs from your wall to do this, it will blow your house fuses in protest. The reason for the variations ( in the ultrasonics ) is the big inductor in the outputstage that protect fex tv sets from the strong ultrasonic noise that all digital amps generate, not the rest of the amp. The dip in the curve is the inductor ( coil ). Driving a complex load doesn´t make it better, but the difference in sound ( and measuring ) to fex a Rotel will be much more obvious with a loudspeakerlike load.

(2) The reason for Azrayan starting this thread was not to make everybody say halleluja for the eARTwo amp ( i hope ). It was for the Outlaws to get their eyes up for this technology. The eARTwo is a niche product for early adopters who want " the best ", but that will not last for long. This is a potential $200 - technology not 10X that. What do you think the eARTwo - guys pay for the modules? $100?...$50?
If interested, anyone can order a $300 ZAPpulse kit from DIY cable.com and get a 200-400-600 W @ 8-4-2 Ohm power amp just by adding ones own trafo, rectifier and caps.



[This message has been edited by AndersP (edited August 13, 2002).]

I pretty much agree with that, except:

(1) 10kHz is not ultrasonic.
(2) I've said all along, nothing is there YET. When this happens there may be a compelling reason to get a digital amp.

Charlie

Today it came to my attention, what is said to be common knowledge in the bizniz, that the ICEpower modules sell for $40......

Is that an evaluation price or a 1000 price? If eval I might try some in a powered speaker....

At that $$$, even with other parts and some markup a decent amp could be very attractive IF someone would sell for a reasonable price. Kinda like DLP - looks OK, a few issues, promise of great quality and low price, but early implementors are wringing the $$$ out of it while they can.

My take on this deal is really pretty simple - they don't out perform or at this time under cut existing technology, so I'm interested, but only casually. But that is, as you point out, tangental to the threads original topic.

Charlie

If someone (Outlaw would be fine) could build an amp based on this or similar technology that met these criteria:

Runs cool
200w x 2, 8 ohms
350w x 2, 4 ohms
500w x 2, 2 ohms

700w x 1, 8 ohms
1000w x 1, 4 ohms

Fits in a 1u chassis
Sells for < $400

I'd be interested, but until then they're outclassed by existing technology.

Charlie


[This message has been edited by charlie (edited August 14, 2002).]

Charlie,

As Anders points out the sound quality of say Krell vs. Rotel is a BIG diff. yet when they drive typical speakers @ typical volumes their distortion 'specs' would both appear to be basically flawless (as most solid state do).

You seem to like the idea of a digital amp due to it's eff., but I can tell you that by far the most important attribute of my eARTwo amp is that it's sound is drop dead stunning!
An issue you continue to doubt is 'here yet' and not just a 'dream of the future'.

The ICEpower module IS pretty cheap (as are basically all the digital amp modules on the market.

The eAR amps have taken Peter Thomson two years to refine and perfect to the point they're at today, and their specs are first rate and very diff. from the raw ICEpower module.
This is NOT a decent power supply slapped onto a cheap dig. amp chip and then overpriced.
Is it as cheap as it could be? No, but he (like all the high end companies) don't do high volume sales and must price higher to pay for the R&D and low volume production.

He's well known for only using the VERY best parts in the world. In his speakers he was the first to use Scan Speak's 6 1/2" Revelator woofer. Krell was the second -though their speakers are $10K and $20K. Krell uses costly curves aluminum cabinets, but NOT $10-20K costly!
Peter uses conventional MDF but in a braced asymetrical tetrahedron shape for no internal standing waves or vibration (unlike the Krell) and perfect phase allignment (unlike the Krell). Peter also uses and designs his own x-overs from the best of the best parts.

The analog modulated ICEpower module was hand picked by him as the only digital amp that could have the benefit of digital amp's speed and analog amp's benefit of liquidity and purity of signal.
It's unlike all other digital amp modules.

His amps are most certainly in the low end price range of super hi-fi and will compete with any other amp on the market. No solid state or tube amp and been called better by anyone -at least so far.

Dynamics like solid state just can not ever switch fast enough to do.
Liquidity and purity of signal that only the very best of solid state can come close to, but more typically found in tube amps -that have horrible freq. response and poor dynamics, yet some swear by them because of the liquidity of sound.

The eAR250 is 110W x 2 and ~$2,000, and has money back guar. (as do all his amps) so if you really must continue to discount this amp's sound quality based incorrectly on the raw ICEpower specs (which though not spectacular are still the best of all digital amp modules), you need to buy one and compare it to your amp whatever it may be.
From day one (no break in), you'll hear for yourself how it smokes your current amp.

If you love music, you'll thank me for bringing it to your attention. I know I thank those that pointed me to this new amp.

The 'bigger brother' of same design the eARTwo has been called the best amp they ever heard by everyone online who's bought one.
Many people by now, and directly compared to Krell, Levinson, Oddysey (sp?), Pass Labs, BAT, PS Audio, TacT, Bel Canto, Norh, etc...

I swear to you it's stunning the reality this amp breathes.

I don't mean to be rude, but I'm very skeptical of these sort of claims. To illustrate: I've walked into a friends house and thought "it sounds like XXXX has new speakers... Klipsch?' and been right, at least regarding new speakers and sometimes the brand if they are distinctive (like Klipsch).

I've never walked in and thought, "hmmmm, sounds like Tom has a new HK amp".

So I suspect that while they may very well sound different, the difference is (I suspect) subtle. There have been plenty of blind tests that indicated audible differences in amps, but I've never been just blown away by an amplifiers distinctive 'sound'.

The comment regarding amp speed makes no sense to me - either it can reproduce an 18kHz sine wave or not. Or is that not what you mean?

Charlie