Are integrated amps technically better than separates?

Not a good thing to put your sensitive preamp circuitry in close proximity to the power supplies for both the preamp and power amp.

One of my  preamps has a separate power supply that is connected to the rest of the circuitry by  special umbilical line - they recommend separating the two by at least a shelf or two in a normal stereo rack.  The power supply also functions to provide power to other components.

Certainly an over the top approach, but that reflects thinking at that time on the topic.

https://www.youtube.com/watch?v=-cXCFfec5mI

The power amp it plugs into is also pretty extreme

https://www.youtube.com/watch?v=RE5nlQ9LPYY

In my Audire amps, with its two 500 watt transformers, 8 26,000 mf caps, multiple outputs and big heat sinks, there is no room for similar, but smaller preamp parts.  Not to mention (What a phrase!) the magnetic emanations that would require major shielding between the big amp parts and the preampe.g.  I am not enthralled by 1000 watts of transformers, and 208,000 mf of magnetic/electrical generating devices next to my moving coil preamp.  Why don't we just add a tuner, too. and a CD player, then carry it around on our shoulders?

I would like to share my PC experience, however, I will not mention the "high end/boutique" brands used.

The amps I use are Krell KAS dual chassis monoblocs.  These, have a built in volt meter on the bottom chassis, which show/read power coming in directly from the wall outlet. Changing/swapping out PCs has a direct effect on what the incoming volts are and thus what is illustrated on the built in meter.  Unless the amps are biased to any one PC, the volt reading changes in regards to the PC used...and so does the sound quality.

Best,
Jose 

@cleeds, Naim Audio’s NAP-300 is built in two chassis, power supply separate from main unit. Also Musical Fidelity has done them, probably many more over the years. So not a new or novel approach. Is it “better”, don’t know, but I suppose it meets the designers intention, and maybe ears?

Granted, the Naim is a power amplifier and not an integrated, but.....

This is the first post I have ever made on Audiogon, and I am not a tweaker whatsoever (I just changed speakers after 25 years when a great deal for KEFs became available). I look long term and buy used or new depending on the item. I have found the most difference in the phono section by far (arm, cartridge/phono stage and table in that order). I didn't realize how much improvement could be gotten from a separate phono stage (or head amp as we used to call them). 

My integrated amp which is phenomenal (Plinius 8200MKII), has a built in phono stage which I thought was equal to the other parts, and until I got a MC cartridge (VanDenHul Special One) I never thought about it. When I got back into thinking about the hardware in the past year or so, after upgrading my Rega P5's arm to the one on the new P8 (the dealer sucked me down a rabbit hole) and finally upgrading the table itself, someone mentioned that although the Plinius phono section is good, I could get a big improvement with relatively few dollars spent (although relatively is a relative term). 

Since I upgraded each part in incremental steps, the arm improvement blew me away, and although the table sounded better it was a very subtle improvement thought it has a couple nice features. I just got a Sutherland Insight phono stage a few weeks ago (lucky to find one used) and once again I was blown away. It was based on the recommendation of several dealers. I would have bought a new one if I didn't find the used one. The guy who sold it to me set it up for me based on the VHD specs. You can see I am not a tweaker.

Bottom line in this discussion, make sure to separate the phono stage first, then worry about the integrated/separates argument. I lean towards integrated for space and value, but like I said, I am not a tweaker or tube guy. For the hardware hobbyist - have fun with tubes, separates, mono blocks, sub woofers, etc. For music lovers who like to keep it simple and mostly listen to music while doing other things KISS.