The right channel gave up on me after only one year. Luckily for me, the reseller replaced it for me even though I had no warranty anymore... It had expired some days earlier!
But one year later the problems came back: Crackles and signal dropouts, both on the right and left channels. Very annoying for monitoring and listening.
It seems to be a well-known issue of this product, which the resellers tend to keep to themselves...
Despite its good audio quality, I advice you against it!
I would certainly not buy it again.
I would go for some active monitor speakers.
I've had my Alesis RA 150 for about seven or eight years. It came into my hands in an unlikely fashion and I have been using it in a variety of ways since I got it. It is a compact dual channel power amplifier, good for power monitors that may be un powered, or for using it as an head for a bass or guitar cabinet. It has both XLR and 1/4 inch outputs to send to a cabinet or speakers and it also has connections for speaker wire. In the front of it there is a headphone jack and a power switch. It then has a volume knob for each channel with green and red LEDs to show output level and overloading. I have used this amplifier successfully in a few ways. Right now I am using it to power a pair of Yamaha NS-10M studio monitors and it works flawlessly for this. In the past I have used it as a bass and guitar head by plugging my instrument into it and sending the amp to a speaker cabinet. While I didn't get as much juice out of it in this application that I would have liked, it did the job. I used it for mostly bass guitar as this worked much better than guitar. However, this unit is probably really designed to power studio speakers, and works best in this application. The price won't make you dig too deep, and I'm not sure you can find too many of these around, but if you can find one and need a compact power amplifier for your monitors, I definitely recommend it! While not extremely versatile in its use by any means, what it does do, it does it well and has a pretty good amount of power for a single rack unit. I recommend the Alesis RA 150 to anyone on a budget looking for great quality.
I bought this amp to set up a decent home studio (almost 6 months ago). I invested on the RA150 and the Alesis monitor one mk2 after the guys at my local shop recommended it to me.
The result is really good!!!
Nothing to say about the brasses (jazz), classical music violins and layers, the kick and snare drums (hiphop) come through very nice, and don't even get me started with the basses!
They are almost noiseless and even if you ever hear some noise it's probably due do how that particular sound was recorded.
To be honest, this gear has really made me develop my chops, both in terms of songwriting and mixing.
So I really recommend this amp with the Alesis mk2!!!
EXCELLENT value for money!!!
Would I buy it again? Yes, yes, yes!!!! (however, if I had more money I would look at more pricey options).
To conclude, they are awesome for computer music, songwriting, mixing, hip-hop and r&b recordings...and they allow you to get a good home-studio quality.
Edit from June 2010
After moving it with this heat, it won't power up.
Then, once I got it sounding again, sound was intermittent.
Sound just came on and off, in other words, impossible to use to make any music.
I hope it's only a false contact or the tube that needs to be replaced. I'll go tomorrow to the shop to see what's wrong.
It's a real pity because I was very satisfied with it.
It seems I'm not the only one with this issue, so its quality certainly leaves a lot to be desired.
I'll tell you more in a couple of days and revise my review, if necessary.
This is the first time I write a review here, despite several purchases, because the manufacturing quality of a product rarely surprises me, considering its price.
I was (very) pleasantly surprised by this amp. I originally bought it for a small bar. Since I didn't need too much power, I opted for an entry-level studio amp, with the idea of having the best possible quality for the same price.
And well, it didn't disappoint me! I stumbled unto an extremely well-conceived product. The outputs with servo-adjustment guarantee a sound without any noise, regardless of the level. After opening up the amp, I was pleasantly surprised by the size of the power supply, which guarantees a realistic performance (250 VA for a 2*75W amp is rare at this price point!), unlike many inexpensive amps (I had an unfortunate experience with a no-name amp that cost 100 euros and supposedly delivered 2*200w with a 75VA ... what a joke) .
I insist on this point because it's important from a reproduction point of view and even some renown monitors (like the new active Genelecs) feature undersized transformers. The amp has an extremely well-conceived discreet circuit, which you can tell from the sound! Compared to a basic, 80€ Hitachi hi-fi amp (everything I had at my disposal), it's like night and day, in terms of noise, precision and power, despite the Hitachi being rated at a higher output power.
In short, there's no trickery in terms of quality with this unit, which isn't the case with many products at this price point, even from renown manufacturers. It really makes you want to have passive monitors, even though you lose the advantages of bi-amplification, and there aren't many good passive monitors.
So, if you are looking for a quality amp, be it for studio or PA, and even for home use (if you don't need the embellishments of a hi-fi or home-cinema amp), go for it!