Take a look at these measurements though. I was just curious when I noted an integrated amp on Crutchfield with the famous old LEAK name on it. That integrated does actually measure better than a receiver, not that you will likely here it. However, that amp represents good value for money for what it has to offer, and would be a good choice for what would be an audio only system or one where you might want to get the audio from a TV as well. I think they actually did Harold Leak's name proud with that one. Among integrated amps that has to be a top recommendation.
Sorry but please take a careful look and compare a popular receiver, in fact even an AV receiver that we know you don't like at all lol.. You can always find a receiver that measured worse than this mid range Denon, but you can also find integrated amps at the same price point that measured a lot worse than the Leak 230 right?
I didn't look at the Leak 230 before, so let's see now at their corresponding distortions, by comparing the almost apples to apples distortions that the OP is interested in, in this case the typical 1 kHz, 4 ohms sweep of THD+N vs output that both Stereophile and ASR would do on their test bench.
Leak:
Fig.6 Leak Stereo 230, line input, THD+N (%) vs 1kHz continuous output power into 4 ohms.
Receiver (Denon AVR-X3600H):
Also 4 ohms, 1 kHz
And compare their THD+N
At 100 mW and the knee point:
Leak amp THD+N........................................................
0.018%
Denon AVR..................................................-75 dB =
0.0178%
At knee point:
Leak amp THD+N......................................j..................
.0.01% at about 100 W
Denon AVR............................................... -86.28 dB =
0.0048% at 166.8 W
So, very little difference, but the receiver measured a little lower (a touch less that half that of the Leak amp) distortions and output a lot more.
The Arcam A25 indeed measured similar, also by Stereophile, but it's distortions at 100 mW was quite a bit higher than both the Denon receiver and the Leak Stereo 230.
That's just one measurement, if you take the time to compare the many other metrics you will find that those 3 integrated amps didn't do better at all. That is not to see everyone should buy receivers, just enough to say if they buy one assuming they have lower distortions and sound better would be based on myths, not necessary (yes in some cases obviously but not always, and it could go either way too) fact. There are other good reasons to go with integrated amps for sure.
