After the modifications we've done to the DB1080 it's time for some results! Unfortunately i don't have proper measuring equipment so i will try to describe the differences as best as i can.

It's difficult to describe the phenomena if you haven't experienced it yourself, but proper stereo will sound like surround. Some tones or timbres will fill the entire room, you are immersed by it.

On a bad stereo set you will hear the sound coming from the speakers and it won be spatial, hence the expression 'flat sound'.

So right off the bat i was able to hear the difference, which is good because that means the investigation was on the spot. But lets not jump to conclusions here, i was happy with the results i got but the DB1080 definitely wasn't replacing my AKAI AM-32 anytime soon.

A good example in real life would be to watch the stars on clear night without glasses. You can see all the bright objects, then someone lends you his glasses which happened to suit your eyes approximately. Suddenly you see everything in between the stars and you become mesmerized by the image.

That's about the difference a good amplifier can make. But 'perfection' needs more time and adjustment.

As previously mentioned, op-amps are miniature amplifiers and every circuit design has its own tonal character. The NE5532 produces less distortion than the M5281 does, but it lacks the bite the M5281 had. I do not know the cause for this i just noticed it after listening for a while.

I sometimes listen to chiptunes because i like the cranky digital sound, the M5281 wasn't spatial by any means but it was able to produce that spicy bite. The NE5532 is like mildly spiced Chinese food.
I personally like that spicy flavor, so perhaps this could become my next quest.

Having a surround receiver that is able to perform like a stereo amplifier is quite something, so i got very curious what effect this would have on the surround experience.

I put in Ernest et Célestine (2012) and was just blown away by the performance. I never had such an experience before, my setup sounded so much better than the cinemas ever had.

It was almost as if you were there on site. I know that really sounds cheesy, but that's what it feels like.

The sound was also much more pleasant at higher volume levels and voices were much clearer.

This definitely got me in the mood to upgrade my surround speakers and see if i can further improve the experience. All in all just awesome.

I started out with the 'simple' goal to make a surround receiver perform like a regular stereo amplifier, getting rid of the dull/flat sound and reduce the harsh distortion.

I can definitely say i have achieved my goal and got the pleasant surprise of discovering what true surround is capable of.