OK, FredK and JohnK (and many others) have taught me much in the last months about amps. My opinion has changed dramatically, and my opinion yesterday was that it only really matters at the edge of the amps power limits, where dynamic peaks go beyond the amps clean power range.

Turns out, i was right; and so were John and Fred. Today I decided to stop pestering the educated folks laughing at my Krell/Bryston/McIntosh erection and go get a damn amp. So, because I am cheap, I went to Guitar Center and found a Crown XLS 402 stereo amp for $350. The musician I found there said Crown is the live standard bearer while other were more recent entrants to the field, so I figured that was safe for a purchase I expect to return in a few days. My speakers are 4 ohm, so it makes about 450 watts per channel. My AVR is a 2001 Denon AVR 3300, that I love, and is rated at 110 wpc. But test reports say it starts to clip the signal at about 80, and hits 1% distortion at 180w into my 4 ohm speakers. Again, i love the sound of this amp, and I like it loud.

So I hook up the Crown and skip the six week burn-in. I heard that is BS! Final verdict - it is better, noticeably better. Here's why: Peaks are dead clear. I thought my speakers added some harshness at the edge of male voices and the peak of guitar and other string solos. Not so, it turns out. My AVR adds distortion, at high levels, to mail voices and high guitar notes. That's the long and short of it - my AVR was outside its clean zone more than I ever imagined.

Also, music has more peaks that I knew. Listening to Dave Matthews at RCMH (Blu Ray in 2ch PCM), I used a meter to see if it was just the volume making it sound "better" [quick answer: yes it is] and noticed that on the first track, Bartender, the SPL meter went from 92-94 constant, to peaks of 101-105 - CLEANLY. On Dire Straits "Ride Across the River" it bounced off 109 [yes that level is F'n loud] but it never distorted. On my Denon, the dynamic range was much more limited - between 92 and 100 on DMB. And since the amps don't add anything to the music, I know that was in the recording, but my Denon just could not get there.

As I said, it is the volume that matters. What I did not realize is that the "volume" is a second by second issue. I was thinking loud day versus quite day, but turns out the volume is much more dynamic than I knew and those peaks really add something.

To keep this rather short (for me) I'll say this: the amp makes little or no difference (as Fred and John say) for most listening. Sitting here with DMB at nice soft levels (80 to 85 db) it makes no difference that I can hear. (Actually, I perceive some mild changes, but I think they are psychosimatic).

But if you like it louder, or have a bigger room, the extra power is immediately evident. With 400+ watts flowing (never clipping the amp) the guitar plucks, the DMB wails, the Knopfler picks (all without a sub turned on) you get clean sounds at the edge of you old amps ability. You get the clean sound of 85db but at realistic levels. You won't notice it every day, but for critical listening, you will appreciate the difference because the music has more dynamics than I ever knew. I keep turning it up. DMB on piano, turn it up more. Tim Reynolds on guitar, make it real. I'm hooked.

So everybody was right. But man, even my wife was impressed with Dire Straits at levels she would never listened to just my AVR. For $350, I'm having trouble figuring out why to return this amp. The fans or loud, but apparently that is a problem across the pro amp realm so I might just have to adjust. The real issues is THD (as warned). I notice in quite parts more background hiss than I am used to. This amp has <.5% THD, and I know that should not matter, but Alan's reference to .2% is leading me to think I am hearin that .3 difference. Could be the AVR (now 2ch pre-amp).

Uh oh, might be the signal wires! I'm using some non-levitating copper wire. I bet that is the hiss.

I can't freaken imagine what the Axiom A-1400-8 sounds like with about 3 times this much power on tap for 8 channels without the THD issue. And now I see the value of that amp. I would need 4 of these A/B amps to equal half the power of the Axiom, while the Axiom is the size of one of these Crown amps and skips the hiss. Nice job Axiom.

Three year warranty for whatever that is worth. Thanks all.

Nice review Zimm, I'm glad your happy, as am I with my Odyssey monoblocks, that is even better than a stereo amp.

Nice post Zimm. Thanks.

You're wrong, I tell you! Delusional!

Oh, I love upsetting the spell-check police. Your email shows your intent desire to maintain your forum.

If I return the Crown, I think I might go the Odyssey route - they are clearly the best deal I have seen, with Emotiva close behind. But even there, getting to 400 watts per ch gets expensive. I think there are some pro amps that get below .2% and I may try to get one of those. But for $350 (plus $20 in balanced-t-RCA plugs) this is pretty impressive. I looked inside, and this thing has a huge toroidal transformer, but there are many competitors in the sub-$500 class. So why can't Emotiva or Odyssey make a 500 watt (4 ohm) amp with RCA inputs?
I still don't get that. Economics is a part of my daily life and supply and demand should have exploited this issue long ago. Maybe THD is a real impediment to massive power.
There must be something to explain why Crown, QSC, Mackie, Yamaha, and other don't offer a HT version with RCA plugs for half the price of Rotel, et al.

Nice post.

IMO, THD is one of the most important numbers to consider when buying an audio/AV amp.
For some reason, (which I can't recall just now) most A/V amps have high THD numbers until you get into fairly expensive (relative) equipment. I don't care what anyone tells you......you will hear 1% THD.

LT61, even inexpensive amps have low (< 0.1%) THD now.

Very good, Charles; enjoy. I do have to comment about one statement however: 80-85dB is by no means a "soft" level, it's quite loud and is the upper limit for long term exposure without hearing damage. For example, ordinary conversation with a nearby person would typically be about 60-65dB(doesn't always apply to wives)and 20dB above that is quite a significant jump considering that a 10dB increase is said to be subjectively "twice as loud".

Nice post Zimm.

I agree with the fact that the amp plays better loud, but I think at most volume levels, not just high.

I tested my amp with an SPL meteras well and from 75db and up it made a very significant difference. I can listen at lower db levels now and get the same sound I would get only at higher volumes. The speakers just come alive sooner

That was with M60's though(8ohm) so we might just get different results.

I couldn't edit the above post.