So, following on from my ‘de-mulleting’ thread, in which I’ve been converted to source-first by my recent upgrade to an NDX2, I now need to sell a power amp to pay for an XPS DR! I’ve got a recently serviced 300 (non DR) and a newish (2019) 250DR and I’ll sell one of them to fund the XPS. So, I sat down this afternoon to decide which one to part with and it ended up being quite an involved decision?! After some head scratching, I picked a few tracks that I know well and which are on the difficult/fatiguing side of music and then randomly invented the following categories:
Slam - how much like live music do bass guitar and percussion noises sound?
Liveness - the extent to which the ‘curtain’ between you and the performer is lifted
Naimness - how much of that slightly forward ‘Naim’ presentation is there?
Blackness - how clear and dark is the space around the music?
Warmth - how much warming ‘colour’ beyond the music is added
Fatigue - how tiring a listen is it?
Tapping - was I involuntarily tapping my feet? (hard to know what’s involuntary in such a test)
Scores out of 10, averaged across songs.
The idea was that higher scores were better apart from Fatigue and Warmth which, for the chosen songs should be around 5 but I have a personal preference for a very slightly warmer presentation - given my room etc.
My findings were kind of interesting. The 300 got the ‘best’ scores for Slam and Liveness. Both amps got the same score for ‘Naimness’ - they are both centre-line classic Naim products I guess. The 250DR won by a modest but worthwhile margin on Blackness and the 300 was a tiny bit warmer which I personally liked a little better. I found the 250DR a tiny bit more fatiguing (perhaps the mids were a little more congested) and the 300 won in the ‘Tapping’ department, but not by a huge amount.
The 300 hisses through the speakers a little more with no music and the transformer is a tiny bit louder (though much better since its service) but, overall, I do think it edged the 250DR - though as you can see, it’s hardly a ‘night and day’ thing.
I guess I’m interested to see if other people have a different way of evaluating their listening when making these sorts of decisions? It’s interesting to know how we all objectify what is really a subjective thing.
From my side, I think I’ve decided to keep the 300 and forgo they wonders of a DR power amp in favour of funding the XPS DR. If anyone has any last A/B testing advice though, I’ll be delighted to hear it.
How long can you keep both for? How about just leaving one in place for a day or so, swap over for a day or so, repeat a few times. You’ll probably develop an instinct for which one you prefer listening to. If still not sure, just walk up to them and let your hand subconsciously rest on the one you want to keep.
Surely any fatigue instantly rules one out? Or are both fatiguing in some way? (In which case maybe resolving fatigue would be a better focus of attention? Playing music shouldn’t be fatiguing at all - quite the opposite!) If fatiguing I’d look to the speakers more than anything.
Ill second that and say possibly keep them in place longer. In my experience audio memory is so short, sometimes it is really hard to tell anything from AB comparisons.
These days if I am trying to decide between two things, e.g. speaker cables or tweeter attenuation (diy speakers) I leave in place for long enough that I become familiar with them on my most frequented music. Then you really get an idea of the fatiguing aspects, and when you switch to something else the change is much more obvious.
As mentioned the AB comparison back and forth can be confusing and a bit of a pain depending on the items being changed. I tend to put the gear in place and leave for a good week or so, more if running in. Then revert to my old unit(s), if i miss the new items i keep them, if not they go back.
I almost stopped AB testing because it most often drives me insane and I have in the past drawn to fast conclusions. Proper AB testing need lots of time and perseverance. And I’m at a point where I don’t trust my ears anymore. The brain, mood and expectations are tricky things to master.
Before I sent the 300 away for service I did much the same with a 250-2 v the 300. I found the instantaneous difference less obvious in terms of preference. Listening over a period of a couple of days and then swapping back was when the differences were really highlighted.
I decided l much preferred the 250, hence the 300 being serviced, and then the rematch
Many thanks for the ideas. It’s really interesting to see different people’s approaches and philosophies to evaluation. I’ve been a bit quiet in this topic for a few days as I got the opportunity to pick up a pair of older but very nice ATC SCM 100 actives and so now have both NAPs disconnected. The ATCs have only been running for an hour but I think they are staying. They are just awesome. I’m glad lockdown is almost over so I can get out of the house and stop buying bits of hifi!
I carried out extensive A/B testing with NAC 202, 282, NAP 200, 250DR and Hicap DR about 2 or 3 years ago as I had all the amps in my system during that period. The differences were marked when any component was swapped. All possible permutations were tried and tested. There wasn’t really a methodological approach to the A/B test as I only tried to listen to the differences. I noticed you have created different categories with the evaluation and I can surely relate to most that have been written. Apart from slam, liveneness, Naimness etc. I also listen to the bass, detail across the frequency spectrum and the refinement in the delivery such as decay of notes and space between notes.
I had no issues picking up the differences with quick swapping of the amps. However, I had problems doing A/B test with cables, particularly interconnects. There are differences but it gets complicated if the cables are swapped too many times. The perceived difference which I previously heard became non - existent when I listened for the 2nd or 3rd time.
In summary, if the sound differences between components or cables are too minute during quick A/B evaluation within a day, I concur with the suggestions to listen to the gear for several days or weeks before switching to the new gear where the differences will be more noticeable.
