Best bang for buck integrated amp for $500

I can personally vouch for the Cambridge Audio AXR100.  It is actually the best integrated/amp I have ever owned.  I'm surprised at the low price; I believe it must have been designed so good by accident as people say it is better than Cambridge's more expensive amps.   I have it paired with Tekton Lores and the combination is other worldly.   You can find a lot of rave reviews on YouTube.

Best!

Well i got the Rega today and here are my first impressions. There is way more clarity, openness, loads more detail, more soundstage. Im am totally blown away buy the power, the kick this amp has, i mean im at 9 oclock and its blasting loud, the cambridge i had to go much higher, but it has 85 watts. The warmth of the cambridge is gone, the slaming bass of the cambridge is gone with the Rega.

I have to say im still checking it out, there 2 totally different sounds completly. I can say i miss the bass of the cambridge already, and that warmth. The Rega is so clear and defined and open, hmmmmmm tough call, need days of hearing both to decide, but its not a easy choice..  I was hoping the Rega would just destroy the cambridge and make it easy, but no.

Well guys it's come down to trying to decide between my two amps.  Things that I do and don't like about the Riga IO so far.  The biggest Plus I think is if it's on my desktop I love that it seems like it's built very well very quality made good connectors on it and a surprising amount of power for only 30 Watts I think that's the most shocking thing about it to me.  Things I don't like I don't like the volume knob it's really hard to turn it doesn't have an indicator on it it has a notch in it but you can't see it because it's black like the knob the numbers on the front that tell you what input your on you can't even see the numbers Hardly they're so small and they're not well defined.  

I think my biggest gripe so far the thing I just don't know if I'm going to going to be able to get past to keep this amp is it has no Bass the bass that it has is good base but it doesn't have low in grunt it doesn't it's just lacking base and it has no sub out.  Don't get me wrong I'm not a bass head but I do like Bass the io just seems seriously lacking.  On the other hand the Cambridge audio axr 85 has got pounding good bass.  What it is I want to take things from the Cambridge audio and put them into the Rega IO you can't do that I can't keep buying amps and shipping them back until I find the amp I want it's too expensive in return shipping.

I would have to say out of the emotiva bass x a100 the Cambridge audio axr 85 and the io I would say the best one I've heard so far believe it or not is the emotiva.  I got a couple days off of work I'm going to switch back and forth between the Cambridge and the io for 2 days off and decide which one I want if the io had a sub out it would be over with I wouldn't even be having this conversation because I could add a sub.

Well,it seems you like the sonics of the IO best. You can use a subwoofer via speaker outputs. The built in amplifiers have very high input impedance such that the amp doesn't 'see' an increased load. 

Check out the sub threads here on AG.

I’d say first off - you’ll have to let the IO run in for at least a week. Let those transistors settle down after shipping and everything burn in. Listen to it for a week or 2 and then switch back and see what you think. I’d expect the bass to open up for you as well. Especially since you like the tone and clarity.