New 7500 review at Ultimate AV

This review at Ultimate AV was posted yesterday, it appears. Very complementary of the Model 7500...

Nice review, I plan on getting one as my next amp.

Good review. As much as I loved my 7125, the 7500 is even better.
I just wish it didn't take so long for the reviews to come out after a product is released.
I hope the 997 reviews don't take 6 months or loner.

It was a good review providing both subjective listening and comparative analysis. Plus, the reviewer conducted the first measurements I've seen on the Outlaw 7500--I like that aspect of Ultimate AV reviews--and the 7500 fared well for itself.

I compared the measurements of the 7500 to two other 5 channel amps--the Krell Theater Amplifier Standard (TAS) and the Parasound Halo A51--previously reviewed on Ultimate AV. The Outlaw 7500 measurement-wise was in the same league as the other two. Still, it all comes down to how they sound. I'd love to have a blind listening test between those 3. Anyone want to loan me a A51 or TAS?

Rob

Candyman,

When it come to power amps, all three companies tend to understate what they know they can deliver. In our case, we produce nearly 20% more power than claimed at our rated distortion (.03%) and even greater power at slightly higher distortion. As evidenced with both listening tests and measurements, the 7500 indeed holds it own with some of the industry's most respected brands.

Thanks for pointing that out.

The "measurements" in the Ultimate Audio review consist of reports of distortion at output power levels that aren't going to be reached over 95% of the time in any realistic listening situation, even with the most insensitive speakers on the market. I invite anybody who doubts this to listen to ordinary material at the sound level, measured with one of those Radio Shack meters, that the manufacturer lists for your speakers. It's almost never lower than 80 dB and for, e.g., Klipsch speakers it's up in the 90s. I think you'll find it pretty loud for sustained listening. (If your idea of sustained listening is headbanging rock at concert levels, by middle age you'll be experiencing the distortion levels of hearing aids.) Now that you're listening at that level, or now that you've turned everything down again, realize that you were hearing ONE WATT being delivered to your speakers. Look at the distortion chart in the UA report - logarithmic for the distortion scale (good) but arithmetic for the power output levels (virtually useless). The only information it conveys for the power output realm of sustained listening is that somewhere below 5 watts the harmonic distortion climbs to 0.1%. How high it gets in the area below 1 watt, you can't tell from this chart. And there's nothing at all about the much more irritating intermodulation distortion, or about the ratio of odd (irritating) or even (warm-sounding, even if not quite accurate) harmonics are present.
If you really want measurements relevant to sound quality, (1) the charts have to be logarithmic for both distortion AND power output, the output levels should be measured at least down to 100 milliwatts (remember, that's where most of the actual sound levels are if you're listening to music at "ordinary" levels); (2) there must be IM as well as harmonic distortion charts; and (3) ideally, there should be a report of the levels of odd vs. even harmonics in the harmonic distortion. You don't see that kind of detail often; sometimes in Stereophile, maybe.
BTW the reason tube amps often sound "better" than solid state, at the same price levels, is that most of their harmonic distortion is even-order.
Enough rant. Just remember, measurements like those in the Ultimate Audio report are cheap and irrelevant.

Oops. In my measurements complaint please read "Ultimate AV" instead of "Ultimate Audio". I'm pretty sure about the rest but hope Gonk and/or Altec chime in.

Hey Outlaws, why not get ahead of the high-end folks by giving those measurements in your specs? You might give the whole field a kick upwards.

Even order harmonic distortion components also tend to cover up the audibility of the harsher odd order harmonic distortion components. Tube amps do have odd harmonics, but as can be seen from the following picture of the distortion spectra of a single ended triode amp, the harmonics fall off very rapidly, and are essentially gone by the 5th or 6th harmonic. A typical solid state amp will have distortion components all the way past the 15th or higher. These are very harsh to the ear, even if they are "measured" at .005% or so.