Mono Switch?

I have noticed that many hi-end preamps don't have a "mono switch". I remember my old receiver had not only a mono switch, but had left or right channel played through both speakers, and a speaker reverse [L to R; R to L...not a phase inversion switch]

So what's your opinion of the lack of or the inclusion of a mono switch? Extra circuity that degrades the fidelity, or a useful tool for mono recordings as well as a simple way to check for out of phase recordings?
it's just extra amount of labor that decreases profit.
instead, it's just a matter of spreading some hype about sound degrading.
i have a mono selector switch on my cj premier 3 preamp.
i do not notice any loss in resolution.
I recently upgraded my preamp.......... Going from an ARC LS25II to an Aesthetix Callisto sig. The sonic upgrade was huge, but I sure missed that mono switch on the ARC. Thank god my phono stage has one because I use it mainly for vinyl playback.

Separates have become the province of the purist who has no need for such things.
It used to be that functionalists bought these things and demanded convenience features.
My friend used to have a pre that did all that you mention. The L/R inversion switch was most useful for her because her livingroom speakers were on either side of two doorways. The other sides of these doorways lead to the bedroom. Open doors, turn speakers 180 degrees, flip switch, listen to music without yor head imploding.

Oh well.
One of the main selling points for me on the Thor TA-3000 phono preamp was that it had a mono switch. These things matter and more manufacturers should be aware of that
so, what does a mono switch do anyways? If I traded out my cartridge for a mono one, and listened to mono records, are you saying the result would be only one speaker play? Man, if so, I want a mono switch too!
Mre2007, this is my understanding of a mono cartridge vs. a stereo cartridge.

A stereo cartridge will play a mono record as mono through both speakers with or without a mono switch. A mono cartridge has a spherical stylus vs. an elliptical one, and the stylus tip diameter is larger than on a stereo stylus, to sit higher up in the record groove. Mono is determined by the lateral motion of stylus in the groove, while the stereo is derived from vertical motion.

So with a mono cartridge, you won't get any spurious vertical movement, which would translate to possible phase cancellation of the mono signal.

So, a mono cartridge won't play through both speakers, unless a mono switch is used?

Mre2007, a mono cartridge will send the same mono signal to both the left and right channel...with or without a mono switch.
Excellent. Thanks!
Fatparrot: There was another thread which brought up the mono cartridge question a while ago, and none of us could say for sure exactly what the difference was, or why it would be better to spend $$$ on another cart when a mono switch (which I have and won't do without) would seem to accomplish the same thing with a stereo cart. We speculated about stuff like you mention, but no one could confirm if anything was actually the case with these carts. I'm wondering where your info comes from?

To the topic at hand, yes, I very much value a mono switch, as well as the L or R to both speakers switch, which can also help with playing older mono records where one groovewall may be in better shape than the other. But the latter feature seems to have just about disappeared altogether (my PV-8, which I don't use anymore but won't sell, has this). Bignerd100's account is the first explanation of what a channel reverse switch is good for that I've seen, other than diagnostics. The mono and channel-select features should be incorporated in standalone phonostages, because you don't really need them for digital sources, and so many linestages omit them.

Another feature of yore I'd also like to see brought back in phonostages is a variable cross-feed control (AKA stereo blend), to help with those early-stereo pop, rock and jazz records that suffer from the unnatural "drums in one channel, guitar in the other" hard-panning syndrome, common in the 60's. If you completely mono these records, some will result in excessive phase cancellations in the mids and/or HF, but a progressive separation control could help with imaging/center-fill while still maintaining acceptable frequency response.
Yes that "stereo blend" switch on my Dynaco PAS 3x is quite usefull.
Bob P.
Zaikesman, mea culpa! The spherical or conical stylus tip that I was referring to is used for playing 78 RPM records. I will send an email to Grado, to see if they can help with an explanation!