Power Good Sound Quality Price Pre-amp outputs

No noise filtration circuitry No soft start circuitry

I've been running the 4085 as an amp for 6.5" door speakers and 6"x9" rear deck speakers for about a month now. Power is good, as is sound quality. Amp is bolted to the top of my trunk between the 6x9's and runs fairly cool, even at high volume levels for extended periods of time. For it's power output it is smaller than others in it's class, nice if mounting space is limited. As the reviewer below says, the amp is susceptable to noise from the RCA input lines. This is evident as alternator whine when the amp is at 0 volume from the head unit, with a CD player or FM radio signal even at low volume, no noise. Also when I listen to my local low powered AM college radio station, the amp would emit a noisy howl when driving under bridge decks. The AM howl was eliminated and the alternator noise reduced 50% with a pair of ground loop isolators (extra $25 though)on the RCA input lines as they enter the amp. I'd try surpressing the rest of the alternator by using a supressor that runs through the positive cable,but haven't found any rated for the amps that this unit is rated at. Most of the higher priced amps have good noise filtration circuitry built in avoiding these add ons afterward. Another minor negative is that the amp doesn't doesn't have a "soft start" circuit and does have an audible pop or thump when it turns on. I've had other amps years ago that did this as well. Gain and high/low pass filters are straight forward and precise although they need a small screwdriver to adjust. A set of pre-amp outputs for adding another amp is nice touch,save me from running another set of speaker wires to my sub amp. All in all I like the amp and would consider buying from US Acoustics again.

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Clean design. True ratings. Excellant S/N rating. Decent dampening factoring. Cheap Money.

kinda sensitive to noise in the signal lines (rca cables from head). Gain controls need screw driver.

Great amp, very versitle. I have run this amp as purely highs and mids, then as purely subs (3 mtx 4000 12's), then a combo and finally as purely subs again with 2 mtx 4000 12's. Through 5-6 competitions on in 85-90 degree weather this thing pumped flawlessly never over heating, never even broke a sweat. I run full gain pedal to the metal. Take a look at the fuse rating on the side this will tell you that it puts out what it says it will.

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Conservative power rating, excellent integrated crossovers, excellent sound quality.

The input terminals claim to handle a 4 AWG wire, but there''s no way. You''ll have to get creative, but I''d use 4 gauge to power this thing.

This is an absolutely wonderful low priced amp. It makes good, clean power and has very little to complain about. Unless you''re willing to step price WAY up, this is the amp for you.

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