Mono button

Mono will give the same sound from both speakers. Monaural sound seems as if it’s coming from one place. Stereo, which derives from the Greek word steréos, which means solid, gives the impression of multidirectional sound. 

Mono will still come out of both speakers but it looses the imaging, 3 dimensionality and separation that stereo gives you. 

You must hear a difference... if not, something is wrong - if you listen to a stereo record or cd.

Agreed 

I hear a slight dulling of the sound with mono pressed but it is slight. Play an old enough mono record and it can eliminate noise from virtical stylus movement which wasn’t controlled when the disc was cut. 

It’s not unknown for me to forget to turn it off for the next stereo record and to play several sides without noticing. I don’t seem to enjoy the music any less.

Most noticeable application of MONO is when playing back some 1950s and early 60-s music.

Originally recorded in mono, stereo re-mastering often meant that one instrument was artificially panned to one channel and the other to the other, with no stereo imaging as we know. Mono brings back the order and makes a record listenable - suddenly Miles Davis's trumpet is no longer in the wilderness of a left speaker, but dead in the centre

Finkfan posted:

Mono will still come out of both speakers but it looses the imaging, 3 dimensionality and separation that stereo gives you. 

loses

Hungryhalibut posted:

Mono will give the same sound from both speakers. Monaural sound seems as if it’s coming from one place. Stereo, which derives from the Greek word steréos, which means solid, gives the impression of multidirectional sound. 

and “mono” from monos (μονός) which means both “single” and “alone” ????

Having a mono button is wonderful for anyone listening to mono LPs on a stereo cartridge.

Its also useful for getting levels zero balanced right on recorders with separate record level knobs. Like my ZX9... 

christoph posted:

You must hear a difference... if not, something is wrong - if you listen to a stereo record or cd.

Seriously,if there's a difference it must be so slight that this pensioner's ear could barely detect.

ayap1 posted:

christoph posted:

You must hear a difference... if not, something is wrong - if you listen to a stereo record or cd.

Seriously,if there's a difference it must be so slight that this pensioner's ear could barely detect.

Try it with headphones.

The stereo Sgt. Pepper’s Lonely Hearts Club Band album is  good to test with.

In mono the music should sound as if it is coming from midway between the two speakers, as opposed to spread between them (or even  beyond) with stereo. If it does not have that central focus, then it suggests something is wrong -  the two speakers out of phase is a common cause. (This might not apply if the speakers are unusually far apart (far wider than equilateral triangle with respect to the listening position.)

ayap1 posted:

christoph posted:

You must hear a difference... if not, something is wrong - if you listen to a stereo record or cd.

Seriously,if there's a difference it must be so slight that this pensioner's ear could barely detect.

but it is more than a slight difference - on your level of equipment a good recording should sound like presented on a virtual stage (not the key-competence of naim, but it should be so ). As a test, one can use Pink Floyd, The Wall, the helicopter on another brick in the wall 2 (i use it, if i rearrange my equipment). the helicopter comes from a place right from the right speaker and flies to the left, coming more and more in front of the speakers. in mono, one can't hear this. (I hope i explained right what i wanted to say, english is not my native language). 

ayap1 posted:

.....this pensioner's ear....

What, here?! No way! The rest of us are pretty ripped and in skinny fit jeans.

Can't help about the mono button because I don't have one. But from Adam and Richard's comments I'd like one.

I do wonder if the speakers are wired out of phase. The +ve terminal on the amplifier should connect to the +ve terminal on the speaker. This should be the case for both speakers, of course. If you had previously used NAP135s and swapped to the NAP500 you would need to turn one plug round.

EDIT: Actually just noticed you're using SL speaker cables, which don't have the plug orientation problem. It would still be worth checking the phase though. If they were out of phase you'll enjoy a massive improvement in stereo presentation.

Also check the speakers are in the correct L or R terminals on the amp. It’s easy to get that wrong on Naim amps. 

Innocent Bystander posted:

In mono the music should sound as if it is coming from midway between the two speakers, as opposed to spread between them (or even  beyond) with stereo. If it does not have that central focus, then it suggests something is wrong -  the two speakers out of phase is a common cause. (This might not apply if the speakers are unusually far apart (far wider than equilateral triangle with respect to the listening position.)

[@mention:9451063893109836] , have you tried swapping the polarity of one of the speakers to see if that was the problem?