Aragon 4004 mk2 vs Adcom 555 mk2

Yep, anything in excess is bad, feedback included. Yet, I don't understand the hang up that audiophiles have with feedback. When I say feedback, I mean GLOBAL feedback. It has a zillion advantages that any engineer can name off for you because in the rest of the electronic world, feedback is absolutely critical in just about every circuit I can think of. In audio, I don't think feedback causes any detriment to the sound per se. I have looked this up several times and the post Gmood pasted above has too many inconsistencies to be reliable IMO. Local feedback is present in 99% of amps. I talked to Nelson Pass and what he calls "zero feedback" means he has local feedback but no global. This is fine however no one ever seems to complain about local feedback sounding poor. Kind of funny that guys who buy zero feedback amps for the name are actually listening to high local feedback designs and proclaiming its benefits. An amp with no feedback at all, will crash and burn with most speakers. I guarantee it. I have seen it in the lab many many times. So, before complaining about feedback sounding bad, consider what I have said. There is probably an exception out there somewhere (meaning no NFB at all) but we probably wouldn't buy it due to audible oscillatory reactions with the speaker's reactance. Arthur

You probably have less problems with feedback phasing around one stage (local) than across the entire circuit. So in the real world, local feedback may be less problematical than global feedback, even if the net total dB is the same. In an ideal world, both would be perfect.

It is unfortunate that we use the word "Negative" to indicate polarity of the feedback. That word has negative connotations.

Im not an engineer by any means but I kinda thought that ALL products have to have feedback of some kind. But Ive been in arguments in the past where people are telling me their products sound "superior" due to 0 feedback, and that they can "hear" the difference between amps with feedback and amps with no feedback which I kinda felt was a bit flakey. Ive always thought that what matters in the end is how good the product actually sounds regardless of design,pricetag or "brand name".

I agree with you on design,price tag and name.. Ritteri.But that being said with the right two amplifiers you will be able to hear a difference.Whether it's for good or bad it's not that hard to hear.I suppose there's no absolutes to anything especially in this hobby.Sounds like those Pallidiums are some great amps.Aball you should try to audition some Monarchy 100 SE monoblocks on your Paradigms I guarantee the differences will not be subtle.Also Arthur do you know if the Macs use any Global feedback or just local feedback? Just curious.

Hey
The Macs have some global feedback, yes. That was the source of my argument. But so does most Mark Levinson and Jeff Rowland gear although they try not to say so openly; I asked them and they told me. There are many others, I am sure - especially BJT designs. I bet most bomb proof designs have NFB and I agree with Eldartford about the "negative" name being poorly suited.

I am not sold to McIntosh forever and ever (surprised? LOL!) and want to try different things to compare. This is just my 4th system but I have been financially crunched lately. I have a list of all kinds of amps once I can save some money to rotate at least one added piece. I will add the Monarchys to the list!

Going back to Eldartford's comments: I have a mathematical proof I did for one of my classes comparing local and global feedback effects and most terms drop out in equal cascaded op-amp stages to where there is no difference. However, if the stages are unequal, problems can arise - but those hifi engineers are smart people and they naturally balance the system. I admit however that the proof probably didn't cover all variables and the human ear may be able to clue in on something that was deemed mathematically "negligible" thus far in the formulation. The more I am in school, the more I realize that we actually don't know much about how the world around us works and so each one of us here may be right, or wrong. Either way, we know what each of us likes to hear and that really is the important part. The rest is pure fun in experimentation! Enjoy -

Arthur