Price Paid:  $125.00 from eBay

Summary:
I own several of these (5 and counting), all purchased off of eBay. I am using them in combination with active crossovers and custom made speakers.
I have been impressed with the fact that all of the amps have the same sonic signature -- clean but a little constrained on the high end, which suits my listening preferences just fine.
All 5 of the amps have been remarkably consistent in their operation with absolutely no problems.
These are not high-powered amps, however they provide plenty of power for studio use or for my situation where I am using 3 channels (from 2 amps) per 3-way speaker.

Strengths:
Very clean sound. Consistent build and sound quality. No fans.

Weaknesses:
Spring-clip speaker connectors.

Price Paid:  $200.00 from American Musical Sup

Summary:
I took the approach another reviewer mentioned -- I got a clean, minimally featured amplifier, dispensed with a pre-amp and spent my money on speakers. The amp sounds beatiful and works great. If you can still get a closeout special on the RA100, I would recommend it highly. And if you can't, I suspect that the new series from Alesis sounds equally good.

I ended up with another great closeout bargain on speakers (B&W DM605 S2's), plenty good enough to reveal any defects in the Alesis if there were any. And I noticed that when I said I had an Alesis, the folks at the fancy audio parlor where I bought the speakers stopped even trying to sell me an amplifier to go with the speakers.

Of course, this is only a 75wpc amp (8 ohms), so if you want concert sound levels you might need to get something a little heftier.

Strengths:
Very clear, clean open sound, not at all edgy or harsh. Stands up extremely well to a very decent pair of speakers.

Weaknesses:
I actually like the 1/4 inch inputs -- they really work superbly although it means you have to buy your cords from a pro audio supplier. The cheezy spring clip speaker terminals are a truly weird feature on an amp of this quality, though. I gladly would have paid some extra bux for better terminals.

Similar Products Used:
None lately -- I made do for many years with a consumer gear receiver.

Price Paid:  $170.00 from eBay

Summary:
Hi, I've just got a more complete specifiction of this outstanding product. Here it is!

Output Power: 100 watts into 4 ohms, 75 watts into 8 ohms, per side
THD: 0.05% THD @ 1kHz (8 ohms), 0.19% THD @ 1kHz (4 ohms)
Frequency Response: ±1dB 20Hz - 20kHz
Recording studio reference monitoring
Live sound reinforcement for small venues
Noise: 100dB below full output
Damping Factor: 200 @ 8 ohms
Input Sensitivity: .5 VRMS for full output
Input Impedance: 7k ohms, unbalanced
Input Connectors: 1/4" phone jacks
Output Connectors: 1/4" phone jacks and push clip terminals
Power Requirements: (US Domestic) 120 VAC, 500 W Max
Dimensions: (WxHxD) 19"x3.5"x8"
Weight: 14.25 lbs

If you find this, get it on the spot. You will NEVER be disappointed.

Strengths:
musical; tremendous price/peformance; functional; sleek outlook?

Weaknesses:
input/output design

Similar Products Used:
Audio Innovations Alto, Classe CAP-80 (just a crap), Creek 4040s2, Harmand/Kardon PM-625, Nikko Alpha II (this is great), Rega Elex

Price Paid:  $170.00 from eBay

Summary:
This amp is awesome. I love it for three reasons.

First, I love its design concept. This dispenses you with a preamp if you have just one source (maybe, CD) because it has independent volume controls for right and left channels. This means that you virtually have balance control as well.

Second, I love its sound: it's clean, open, detailed with a nice soundstage. It sounds as nice as my Nikko Alpha II. Maybe, its power isn't enough for some "greedy" speakers, but it will be enough for most speakers available on the market.

Third, it proves my belief that so-called "high end gear" doen't mean gear that sounds really good, at least musically. I don't know about "other" kinds of pleasure such as luxury, status symbol. Before checking this out, I owned a Classe CAP-80. That's an audiophile unit which receives a number of favorable reviews from audiphiles. I went by reputation, and spent $650 to get it. After testing a vareity of configurations with a few speakers from Rega Model 2 to Aegis 3 to Cabasse Galiote, I concluded it didn't deserve the money I spent on it, and sold it: to be honest, it sounded worse than Audio Innovations Alto which cost me $280. Now, Alesis RA 100 came to my home and proved the correctness of my conclusion. No comparison: CAP-80 didn't deserve the 1/3 of Alesis in terms of sound quality.

A few complaints on RA 100. Power handling info is misleading. Many ad say that its handling is 100W but it's into 4 ohm per channel, and how many people reading reviews at this site are using such speakers?? It is more helpful to state that its handling rating is 50W into 8 ohm.

Another problem, probably specific to my unit alone, is that it makes a low buzzing noise while it's working. It's not so obvious but it gets noticeable sometimes.

Conlusion. This product is highly recommendable. If you're lucky, you can get this gem for less than $200 on eBay. With this, why do you still need audiophile amps priced over $1000? No way. Spend $800 to get real speakers.

Strengths:
price, quality in sound and construction, design concept (no need for preamp if you have just one source)

Weaknesses:
poor speaker outputs, no RCA jack, power handling info is misleading

Similar Products Used:
Classe CAP-80, Nikko Alpha II

Price Paid:  $250.00

Summary:
Aside for the minor quibbles mentioned above, this things excells at it's main objective, which is to provide un-coloured power for monitor speakers. Nevermind esoteric high-end hi-fi costing 1000's of dollars, this thing will probably outperform them for a couple of hundred bucks. I run it with a pair of Rogers LS3/5a's which can be fussy with what they're paired with and they sound excellent. The soundstage is wide and open, with tons of detail but still sounding musical. This amp will reveal every little shortcoming in the rest of your system though! I tried a $1000 C-Audio power amp as well and the Alesis beat it easily.

Strengths:
Excellent detailed sound, does just what it says on the box! Only 2u high and heatsink-cooled. Well priced, bargain on the used market.

Weaknesses:
only has 1/4'" unbalanced inputs, dreaded spring-clip speaker connectors. Plastic front panel.

Similar Products Used:
C-Audio