I bought this amp after reading reviews and considering my needs and the price. It worked beautifully - for about two months. Good clean power, silent, no overheating. Then one channel began to intermittently go out. I went online for help. Alesis suggested wiggling the pot. Maybe some dirt. (After two months?) Then the other channel began going out. Then both. I got ABSOLUTELY no help from either Alesis or the vendor. I went online to a user forums, and discovered many (many) owners of the RA series had similar experiences. One person said they solved the problem by themself replacing a part. I don't remember the technical stuff. I'm not an electronic tech person. Seems to me, and many others, Alesis cut corners on materials, had these units produced on the cheap, and we musicians get stuck.

See comments above. Yes, I dealt with Alesis. They were of no help whatsoever, and were not even sympathetic to me having a totally defective product.

Pro jazz musician, composer, videographer

Straightahead jazz, film soundtracks

Produces good clean sound, when it's working properly.

Very basic amp. L&R pots + on/off on front. 1/4" & RCSa IN on rear.

Average (when it's working properly).

Here's where the numbers go WAY down. The RA150, I've learned from researching online, is plagued by problems - scratchy sound, sound cutting out, sound vanishing forever. I bought my unit new in December 2009. Here we are in May 2010. After having the RA150 for a month, the left channel cut out a few times. I looked in the troubleshooting section of the manual and did what was suggested - wiggle the pot a little. The sound returned. Weeks later i got the scratchiness and then cutting out again. It again returned. In February, the left channel departed for good, apparently. Then, end of May, scratchiness on the right channel and going in & out, then no sound at all. I got in touch with the vendor, Unfortunately they were no an "authorized" dealer. Alesis was of absolute;ly no help, not even acknowledging that a relatively new amp should perform well etc. I did some research online and found a forum: http://www.fixya.com/support/t224708-amp_cuts_out_after_while of other disgrunteled RA amp owners. Check it out. Apparently cheap parts from China are the culprit.

OK price if it works as it should.

Not good. Alesis tech people are polite and in my case, not helpful.

clunky. a bit ugly. Really SOLID chassis, built like a tank.

professional jazz musician, composer, video editor

Jazz, minimalist modern classical

For the price I think it provides a great sound. I haven't experienced any noise or anything and I've had this for 2 years.

The only thing that I don't like is that it has banana outs, I'm not a fan of banana cables but it doesn't seem to do anything noticeably to the sound.

Can't really get any easier

Good sound, but I have had to have it repaired once.

To elaborate on my above comments, one day the amp just wouldn't turn on. I had to send it in through the company I work at because we're a dealer, and it cost me about $80 which I thought was a little much.

The price to fix this was about half of what I paid.

It's a cool amp for home studios, but if you can just spend a little extra money and get some active monitors, you'd be saving money in the long run.

For what it is, I don't see how they could possibly make it sound better. It sounds as good as vintage BGW power amps, or newer power amps that I have tried on my Paradigm Atoms. Seems to really let the speakers do their thing. Good reference sound.

As far as features, it is servo so it has good DC shortage protection...but most modern amps seem to have that. It does have a relay circuit to prevent speaker thumps and that's good. However, it could use some better signal leds, and maybe a little more click on the output detents...also more input and output options. But for what it is? Can't complain much.

If you can't get this to work right, you a) Shouldn't be operating a studio at all, b) Haven't read their manual at all, c) Probably don't even know what a power amp is, or why you need one, d) all of the above? Seriously, it doesn't get any easier.

For studio use, you don't really need anything beefier. If you were going to be taking it on the road, I'd worry just a little about the plastic knobs and the plastic front. But if it was in a rack, it wouldn't be a big deal. Plus, knobs are replacable with an aftermarket knob. As for overall workhorse reliability, I kept it in the garage for about a year with wooddust floating around it and even got some wood shavings inside the casing...after spraying out the knobs with some CAIG deoxit (which was really easy to do because of their design) I plugged it in and it worked PERFECTLY. No scratchiness, no hiccup, no odd smells, no general weirdness. The wiring in them does seem to be first rate.

It's hard to go wrong for the price. I can't imagine wanting to buy a more expensive power amp unless you just wanted the image and status of owning a more expensive product.

Can't say anything to this. But I've always heard good things about Alesis's service.

Comeon, who's going to lust after a power amp right? Really though, the non-fan heatsink is great. Also, the blue power light on the front is really hypnotizing. Alesis figured out the hidden secret of electronics; soft blue lights are always more enthralling than bright red or green. It's oddly reassuring, and really draws the eye. So for a basic poweramp, I'd say it has some sex appeal.

Professional music retail, band, private teacher, home recording studio

jazz, rock, brazilian, classical

I use these with Alesis Monitor One MkII speakers. Nice and clean sound. Low noise floor. In my 14' x 14' room I don't even need to turn them half way up. Definitely enough power.

Signal clipping. Signal delay on startup shutdown to prevent thumbs. Notched volume knobs. LEDs to indicate signal presence / clip. Everything I'd want, nice.

Super easy if you know what an amp is. Connect speakers, turn knobs, push big power button.

Feels solid in every way.

Moderate value for the price. It's all I need though.

I think the design looks too space aged. Could be more refined. The position, color of the knobs and LEDs makes it kind of look like a face.

Nice and clean sound, low noise floor

It amplifies two channels, has clip protection, and little leds that tell you when a signal is present / clipped. All I need.

The notched volume knobs make it easy to match stereo volume

Look and feel is great. Feels like it won't break at least

Not cheap, not expensive. It's what I'd expect to pay

I think the front could look a little more reserved and not so space age but that's just preference.

Very clean, detailed sound and it has plenty much power, also.

"Plug and play." 2 volume knobs with fix points - no need to worry about differences in volume between the left and right sides.

I just needed a technical question and they replied almost immediately.

I needed a good reference amplifier for my passive monitors.

mastering engineer

electronic