I’ve encountered integrateds that outperform many separates combos, but also the inverse.
All else being equal, separates tend to be better. For example, Parasound separates outperform the Parasound integrated, as they should given the cost difference.
OTOH, an integrated like the Gryphon Diablo, and to a lesser extent (I dare to say) my Yamaha A-S2100, can outperform quite a few separates systems. For example, my $1600 (used market price) Yamaha sounds better than many separates systems I’ve compiled that mated tube preamps to solid state amps, such as the Allnic L-1500 with a Benchmark AHB2 amp ($8500 combined retail) but the Benchmark LA4 preamp mated to the AHB2 amp is better than the Yamaha in a few regards. I’m pretty certain I would trade any of my current separates/integrateds for a Gryphon Diablo 300, however, even pre-owned Diablos sell for many times the price of my Yamaha. The performance delta is not worth it to me currently. What’s most amusing to me is that the Yamaha’s preamp section better creates all the normally sought tube sonics (lushness, decay, midrange, dimensionality) than any tube-based unit I’ve owned/tried regardless of price, all while being quieter and more resolving.
I had a similar experience as @yyzsantabarbara and @zlone regarding a Coda preamp. I much preferred the dead-silent Benchmark LA4. It’s bizarre that Coda manufactures some very quiet power amps but then compromises the noise floor with their preamp designs. Baffling. They need a new preamp designer, maybe one from Guangzhou, China. 😂
If you can do with a simple pre with only 2 inputs and outputs, the Topping A70 Pro preamp/HP amp is stupidly good and not just for its price. To my knowledge, it also happens to be the quietest, lowest distortion preamp in existence from an objective standpoint.
My only noteworthy experience with Hegel is with their H190 integrated. It produced a very smooth but rather blunted sound. It was mostly underwhelming relative to other integrateds I’ve owned at its price point. If anything it performed better as a preamp/DAC than as a full integrated. One thing for certain is that its claimed noise spec is absolute horse manure. Bench tests I’ve seen for their products confirm that their specs are grossly exaggerated, and their feed-forward distortion/noise reduction “tech” is essentially ineffective.