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Nicky McFicksurschitz « WAY better than expected! »
Published on 06/25/21 at 23:57
Best value:
Excellent
Audience:
Anyone
the a.r.t. sla1 in a nutshell is "thinnish, but incredibly articulate with exceptional separation between channels!"
when pushing 90 db spl sensitivity drivers that meter out @ 6.7 ohms (not 8 like posted), the 100 watts rms per side easily created deafeningly loud audio, and the amp doesn't appear to break up before my ears tap out. the most noticeable improvement was in the stereo sound field both "widening" as well as an apparent "more accurate stage placement," meaning the instruments/voices sit in the pan stage where i put them on the dial, and LCR mixing just sounds terribly lacking now. my ONLY complaint about this amp is a VERY QUIET buzz that exists even when inputs are disconnected, and ground lift makes no difference. this buzz is consistently ~ -100 db @ 1 meter, regardless of front volume pot settings, and does not increase with current push. it is only noticeable in a quiet treated studio when there is NO other noise. the cat meowing drowns out the buzz....
despite the buzz and thinnishness, i still call this a 5 star amp, because it sounds better (read as more transparent with better staging) than power amps twice the price. i am so happy with this unit, that i will be BORROWING a bryston 4b pro off a friend to verify that the extra $800 (used in CDN funds) has enough merit to validate the upgrade.
there is OCD, and then there is PRO-CD; below are my attempts to be pro-cd with backstory and testing:
i bought the a.r.t. sla1 as a temporary amp until i can afford either a bryston 4b pro or the avantone cla-100. i have a small home recording studio with the following signal chain:
win 7 pc (i have lots of legacy firewire hardware that is incompatible with win10)
echo audiofire 12 sound interface (on par with rme fireface for d/a & a/d conversions)
audient nero monitor controller (passes null tests down to about -105dbFS, INCREDIBLY transparent)
a.r.t. sla1 power amp for monitor set 1
cla-10 mid-hi's (avantone's replica of the infamous yamaha ns-10's) running full range (passive crossovers)
twin polk audio 10" powered subwoofers toggled to check subsonic frequencies.
i have done quite a bit of room measurement and treatment using s.m.a.a.r.t. v7 and a rta-420 calibration mic. there is still work to be done, but i've got main reflection points, ceiling cloud, and rear deflection/diffusion handled fairly well with a mixture of roxul afb and fabric. in a nutshell, i've got my playback room to the point where the only real issues are a dominant bass node @ ~47 hz and a secondary @ ~70 hz - both of which go away with subwoofers off.
for sake of comparison, i'll be comparing it to the denon avr-788 in "direct" mode (no eq or processing), the rotel ra-810A (flat eq), and the crown xls 602.
i tried to find a frequency response chart of this unit but failed - just going by ear i would GUESS that there is a -1 or -2 dip between 80 & 250 hz, and then it would be above unity by a db or two from 1khz to 5khz, then the top seems a tiny bit diminished as well, but this is all speculative!
as anyone who travels down the audio fidelity road knows, this is a game of diminishing returns, and the returns on high investments are NOT linear, they degrade logarithmically, so i can say with confidence that anyone who wants great fidelity will not be disappointed with this unit!
below are the direct comparisons between various amps i own:
when compared to the denon avr-788 (home theater amp), it was improvements in all fields (using pre-amp in's, bypassing denon's pre amp phase), but when using the denon with the on board pre amp (in direct mode) i found the denon to be a bit fuller in the low mid range. but very "flat" sounding compared to the improved staging and brighter upper midrange.
when compared to the rotel, the "colouring" of the rotel has never been more apparent! to be fair, i was unable to bypass the pre-amp/eq stage on the rotel, so for this i compared apples to fruit trucks. the rotel dramatically "smooths" out the top end, boosts the lower mids, and has a bit less staging. this comparison really doesn't count because the two amps are engineered for totally different tasks - the art sla1 is meant to stay out of the way, whereas the rotel is very opinionated about how sound should sound. the rotel is more "pleasant" to listen to for it's "hifi" eq stance, but is TERRIBLE for critical audio work. the rotel sounds amazing with my b&w 601's as it "fixes" the deficiencies of that speaker, but the sla1 just makes the b&w's sound "boner tone." (the b&w 601 s2's ARE boner tone speakers, ie: deficient bass & mid bass, exaggerated top end.)
finally the most fair comparison was between the sla1 and crowns xls 602: even though the sla1 is about 1/4 of the power output of the 602, both amps could reach deafening levels in my room. i incorrectly assumed that the larger headroom of the crest meant that it would sound better at high volumes. the opposite was true! the crown had quite a bit of staging issues, ESPECIALLY at higher volumes. the sla1 was WAY more linear in its staging throughout all volumes. at matched volumes (roughly) the sla had better stereo separation, and much "faster" response in the higher frequencies (quite noticeable in ride bells and hi hats). the crown DID fill in the lower mid bass area better but at higher volumes an apparent loudness curve in the crown really kicks in and the bottom end becomes "murky and saturated." the sla1, while i complained about the "thinnishness" earlier, definitely retained that characteristic through the different output volumes.
in conclusion (if you made it this far), the a.r.t. sla1 was a temporary purchase that MAY just be my final amp, at the VERY least, it is a wildly overqualified unit for my 2nd monitor chain. what started out as a short term placeholder amp will now HAVE to be a/b tested against its more expensive cousins before i can justify the expense!
i've attached a photo of my setup taken right before i bought the sla1.
when pushing 90 db spl sensitivity drivers that meter out @ 6.7 ohms (not 8 like posted), the 100 watts rms per side easily created deafeningly loud audio, and the amp doesn't appear to break up before my ears tap out. the most noticeable improvement was in the stereo sound field both "widening" as well as an apparent "more accurate stage placement," meaning the instruments/voices sit in the pan stage where i put them on the dial, and LCR mixing just sounds terribly lacking now. my ONLY complaint about this amp is a VERY QUIET buzz that exists even when inputs are disconnected, and ground lift makes no difference. this buzz is consistently ~ -100 db @ 1 meter, regardless of front volume pot settings, and does not increase with current push. it is only noticeable in a quiet treated studio when there is NO other noise. the cat meowing drowns out the buzz....
despite the buzz and thinnishness, i still call this a 5 star amp, because it sounds better (read as more transparent with better staging) than power amps twice the price. i am so happy with this unit, that i will be BORROWING a bryston 4b pro off a friend to verify that the extra $800 (used in CDN funds) has enough merit to validate the upgrade.
there is OCD, and then there is PRO-CD; below are my attempts to be pro-cd with backstory and testing:
i bought the a.r.t. sla1 as a temporary amp until i can afford either a bryston 4b pro or the avantone cla-100. i have a small home recording studio with the following signal chain:
win 7 pc (i have lots of legacy firewire hardware that is incompatible with win10)
echo audiofire 12 sound interface (on par with rme fireface for d/a & a/d conversions)
audient nero monitor controller (passes null tests down to about -105dbFS, INCREDIBLY transparent)
a.r.t. sla1 power amp for monitor set 1
cla-10 mid-hi's (avantone's replica of the infamous yamaha ns-10's) running full range (passive crossovers)
twin polk audio 10" powered subwoofers toggled to check subsonic frequencies.
i have done quite a bit of room measurement and treatment using s.m.a.a.r.t. v7 and a rta-420 calibration mic. there is still work to be done, but i've got main reflection points, ceiling cloud, and rear deflection/diffusion handled fairly well with a mixture of roxul afb and fabric. in a nutshell, i've got my playback room to the point where the only real issues are a dominant bass node @ ~47 hz and a secondary @ ~70 hz - both of which go away with subwoofers off.
for sake of comparison, i'll be comparing it to the denon avr-788 in "direct" mode (no eq or processing), the rotel ra-810A (flat eq), and the crown xls 602.
i tried to find a frequency response chart of this unit but failed - just going by ear i would GUESS that there is a -1 or -2 dip between 80 & 250 hz, and then it would be above unity by a db or two from 1khz to 5khz, then the top seems a tiny bit diminished as well, but this is all speculative!
as anyone who travels down the audio fidelity road knows, this is a game of diminishing returns, and the returns on high investments are NOT linear, they degrade logarithmically, so i can say with confidence that anyone who wants great fidelity will not be disappointed with this unit!
below are the direct comparisons between various amps i own:
when compared to the denon avr-788 (home theater amp), it was improvements in all fields (using pre-amp in's, bypassing denon's pre amp phase), but when using the denon with the on board pre amp (in direct mode) i found the denon to be a bit fuller in the low mid range. but very "flat" sounding compared to the improved staging and brighter upper midrange.
when compared to the rotel, the "colouring" of the rotel has never been more apparent! to be fair, i was unable to bypass the pre-amp/eq stage on the rotel, so for this i compared apples to fruit trucks. the rotel dramatically "smooths" out the top end, boosts the lower mids, and has a bit less staging. this comparison really doesn't count because the two amps are engineered for totally different tasks - the art sla1 is meant to stay out of the way, whereas the rotel is very opinionated about how sound should sound. the rotel is more "pleasant" to listen to for it's "hifi" eq stance, but is TERRIBLE for critical audio work. the rotel sounds amazing with my b&w 601's as it "fixes" the deficiencies of that speaker, but the sla1 just makes the b&w's sound "boner tone." (the b&w 601 s2's ARE boner tone speakers, ie: deficient bass & mid bass, exaggerated top end.)
finally the most fair comparison was between the sla1 and crowns xls 602: even though the sla1 is about 1/4 of the power output of the 602, both amps could reach deafening levels in my room. i incorrectly assumed that the larger headroom of the crest meant that it would sound better at high volumes. the opposite was true! the crown had quite a bit of staging issues, ESPECIALLY at higher volumes. the sla1 was WAY more linear in its staging throughout all volumes. at matched volumes (roughly) the sla had better stereo separation, and much "faster" response in the higher frequencies (quite noticeable in ride bells and hi hats). the crown DID fill in the lower mid bass area better but at higher volumes an apparent loudness curve in the crown really kicks in and the bottom end becomes "murky and saturated." the sla1, while i complained about the "thinnishness" earlier, definitely retained that characteristic through the different output volumes.
in conclusion (if you made it this far), the a.r.t. sla1 was a temporary purchase that MAY just be my final amp, at the VERY least, it is a wildly overqualified unit for my 2nd monitor chain. what started out as a short term placeholder amp will now HAVE to be a/b tested against its more expensive cousins before i can justify the expense!
i've attached a photo of my setup taken right before i bought the sla1.
