Pro vs. Consumer Equipment

It's interesting that the ART amps have such strong advocates--there must be an exception to every rule.

The JBL pro speakers I referenced included a 15-18" woofer (I can't recall the exact size) and two horns (midrange and tweeter). The McIntosh was a tube amp as was the Crown preamp (at the time, Crown produced consumer components).

Marakanetz, thanks for sharing your views on cables. I wonder whether others have had good luck with pro cables.

While i've never heard the ART SLA-1, i read as much about it as i could find on the net. From what i can tell, it is pretty much the same thing as their DIO dac. That is, ten pounds of parts crammed into a two pound box.

In order to obtain the power output that they are and not run into thermal problems, the amp has to be biased quite low. There just isn't any heatsinking / chassis that would allow a higher level of bias. If it was biased higher, the amp would be going into thermal shutdown on a regular basis. As a general rule, low bias amps tend to sound a lot less refined, lack black backgrounds and do not offer the amount of "air" that a good high bias amp can offer.

On top of this, the power supply has to be compromised for the same reason i.e. small chassis size. There just isn't enough room to get a good sized transformer or filter caps in there. To prove / support this point of view, the amp is rated at 100 wpc @ 8 and only 130 wpc @ 4 ohms.

The logical deduction to all of this is that the amp would lack bass impact, definition and control. I would also expect it to get noticeably "smeary" as drive levels were increased, moreso as the impedance of the speaker were dropped. This all has to do with the lack of available current with limited power supply reserve.

While i know that i've not heard the amp and some of you are probably rolling your eyes / saying what a "dork" i am for jumping to conclusions, you just can't get around the basics of good amplifier design without some phenomenally fancy circuitry being required. Since phenomenally fancy circuitry typically requires a lot of R&D ( research & development ), the end result is typically a product that is quite costly to bring to market.

Given the price / size of this unit and the rated power output, it is probably nothing more than a cut-corner design that takes up minimal space. It was probably built to a price point ( i would assume VERY much so ) and to suite the non-demanding nature that one finds driving small monitors listened to in near-field fashion in a studio. In such a situation, volume levels are never real high and the amp doesn't have to control a large driver with a lot of reflected EMF being generated. As such, it probably works fine for the market that it was intended for ( after all, Studio Line Amp is the name ) but would not be suited for a true "high fidelity" system. Sean
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As usual, a very well thought out analysis Sean. You might be interested in looking at this thread:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1053585689&read&h12&zzlD911&&#rest

A word of warning -- the guy who started it does the mods for the unit. Though he did not fully disclose up front, he seems to mean well and be a true believer.

I'd like to see if this piece lives up to the hype or if it is another case of the "Emporer's new clothes" syndrome. Personally, i thought that the ART Dio DAC was a perfect example of hype. Given the fact that this is a product from the same manufacturer and one of the main instigators of the "internet hype" is a person that could benefit from increased sales of these units ( much like those that "hyped" the DIO and performed mods to it ) really makes me leary of buying one to find out for myself. Sean
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My experience with pro gear is in line with what many have said here vs. consumer home stuff. One major area I tend to find largely "no contest" between the two markets, is that pro equipment tends to stomp all over most consumer high end speaker gear dynamically!...no contest really. Except for the likes of actives and horn loaded ultra high senstivity home audio designs, and even speakers with built in powered woofers and such, pro audio speakers have a dynamic advantage over the average full range home offerings.
One saving grace in a smaller acoustic space of most domestic homes, is crossing over your "audiophile" or "mid-fi speakers" as "small", or using a crossover to a sub somehow, making the system more efficient, even bi-amped.
Basically, running full range, you can set 100 consumer home audio full range speakers next to 100 pro audio full range speakers, and the dynamics and efficiency advantage is going to be decidely on the pro side!...again, no contest. But, at least in a dedicated HT setting, your going to get much needed dynamic help by the use of "crossover" and "bi-amp" applications from sub/sat set-up's, or by at least the assistance of adding a powered sub to the system. Also the smaller acoustic space, as well as close relative proximity to speakers in a home environement is going to help greatly with efficiency, sensitivity needs, as well as dynmic needs of a system! Still, care is needed to try and make up for generally less dynamically able lower sensitivity/efficiency speakers that are the norm from most consumer speaker systems! Again, getting the sub integrated helps, and is deffinitely needed!