Mono switch on phono preamp vs Mono Cartridge

I have two Lyra Atlas Lambda cartridges. One is the SL and the other is the Mono. They are identical cartridges in every way, except for the configuration and orientation of the coils. Each cartridge is mounted on a Clearaudio Universal 12" tonearm, using identical tools and geometry. Both arms have the same Siltech DIN/XLR phono cable into a Boulder 1108 phono-stage, and each input is configured identically. The Boulder phono-stage has a mono switch.

If I play a mono record, there is a clear difference between playing it with the mono Atlas cartridge vs playing it with the stereo Atlas cartridge and engaging the phono-stage mono switch. There is just no contest. It’s not even close. The dedicated mono cartridge provides a lower noise floor, with more air and space between instruments, and bigger/deeper soundstage. It’s a lot more lush and natural sounding. It doesn’t even seem like listening to mono. On some mono records my wife thinks it’s really stereo and is surprised by the performance of mono on the system.

If you have a decent collection of mono records – as I do – a dedicated mono cartridge is well worth the effort. 

And FWIW: most of my mono records are reissues. There are some that claim it doesn’t matter because all mono records since the mid 60s have been cut with stereo heads. Yes, that’s true, but it isn’t the whole story. The cutting heads are reconfigured for cutting, to make a true mono cut. Kevin Gray has a white paper about that somewhere.

@lewm 

If you do acquire a mono cartridge and ancillary gear, I advise you to use the mono switch on your preamp, as well, when playing mono LPs.

That's completely unnecessary with a true mono cartridge. It will make no difference since the channels are already summed (which is all the mono switch does anyway). All you are doing is adding in circuitry that isn't needed. If you think it sounds better, maybe it's just noise shaping on your phono-stage from the mono switch that you happen to like.

Dwette,you extrapolate too widely based only on your own single experience.

@lewm No, I disagree. I think it's a great example of what a real mono cartridge brings to the table.

I think you are disagreeing with something I did not say.  I only advised using a mono switch, if you have one, with a mono cartridge.  I could agree that is like wearing a belt and suspenders, both.  But if your mono cartridge is actually a stereo cartridge in which the two channels are bridged, as many are, the mono switch might further help.  This does not include your Lyra or a Miyajima mono, or any of several other true mono cartridges.