Mono recordings and Mono switch on Pre-Amp


Hello All
I have a question regarding the use of the Mono switch on my Audible Illusions M3A pre.Occasionly I come across an album in the mono format, (aren't these generally more sought after?) and having the provision to use the MONO button,I don't know, maybe I wasn't paying atention but there isnt a difference. Is this the desired effect? That the channel (mono)should be divided too create a Stereo effect?
I use a Denon 103 stereo cart.Am I thinking right?
Also what would be the case if I used a MONO cart?
What makes MONO recordings that much better? I understand that in the days of MONO recordings they used better recording practices that's why they are supposedly better.
Looking forward to your answers

thanks
Jeff
braab8

Showing 1 response by eldartford

The MONO switch mixes the two channels from your stereo cartridge so as to eliminate signal resulting from vertical modulation of the record groove. Since there is no intentional vertical groove modulation on a Mono LP, what you are eliminating is pure noise, mostly low frequency rumble.