Are integrated amps technically better than separates?

On one hand,
in integrated you can make signal path shorter. Especially in low power SET amplifier. You can build 2A3 or 45 amplifier using only 2 stages or 300B with only 3 stages.
In separates you need more stages and more interconnect cables. Each amplification stage, capacitor and cable add distortions and noise. 

On the other hand,
in separated components you can use monoblocks with very short speakers cables, separate power supply transformers and chokes for each channel improves channel separation. A separated power supply for preamp and phono stage make noise level much lower. 

Separates always will be better, technically. Also, separates give you opportunity to optimize amplifier with speakers, without changing signal processing part. In addition to amp flexibility, you can plug active speakers directly into preamp. Moreover, class A and high bias class AB amplifiers running very hot, which is devastating for preamplifier part of integrated, and that will shorten preamp life. 

Each amplification stage, capacitor and cable add distortions and noise.

All those gain stages are in an integrated amp too. Usually though you have a greater chance of lower noise with separates since crosstalk and intermodulations from the other channel won't exist.


To see how profound this is, this morning I was working on an integrated amp, and noticed a very distorted signal at the input of the power amp- on the first stage and throughout that channel. Chased it back to the input, which is all passive components on that amp, and realized that since I was only driving one channel, the unused channel had that distorted input (and output) going on as a result. There is nothing malfunctioning about this amp; but apparently this sort of signal (the result of crosstalk) is adding distortion to the amplifier, which it would not have were the channels merely separated. The amplifier was an older solid state amp made by Trio (Kenwood/Pioneer).

NO NEVER!!

For amps probably up to around 100/150 watts/channel RMS, integrated ones are just as good as separate units as far as sound quality is concerned and definitely better in terms of physical space occupation.

For devices above those ratings, and especially for class A devices, power supplies become the dominant factor and therefore separate units are usually a bit better.

But for most part for the average listener, typically integrated units are easier to set up and they need less space & wiring.

99.9% of people will not notice the difference.  The other 0.1 % will pretend they hear the difference :-)