Hey Lewm, I found some threads that may address the mono switch feature you were talking about.
Here's something to consider, however. Some mono switches may occurr at the phono stage; others may be implemented at the line stage. They would behave differently.
Here's a thread about preamps with mono switches in general. And here's a thread about a specific circuit design at the phono stage that does the things you were talking about such as noise cancellation.
However, note that these are not features you can just go out and buy. The first thread mainly addresses vintage classic items (such as an Audio Research unit) that would cost a lot on the vintage market. The second thread addresses a design that probably has to be custom-ordered and handbuilt.
Then there's the third alternative, particularly the cartridge that started this thread. The Audio Technica unit is a high output (1.2mV) moving coil cartridge, true mono with a -30dB rejection in the vertical plane, and it's readily available for anything from $112.65 to $299.99, depending on the vendor you choose.
Furthermore, if your System profile is up-to-date, I see you have a Kenwood LM07 turntable, which has a universal headshell. You could get the Audio Technica AT33MONO/LP and a headshell, mount and align it, and just play the mono records in native mode. It's much easier than hunting down a phono head with mono switch, and the results would be at least as good.
I'm really happy with that cartridge and it has increased my enjoyment both of latter day mono reissues (Beatles, Beach Boys, Nat King Cole, Gene Krupa) and digging out 45-60-yr-old mono original pressings. Highly recommended.
Here's something to consider, however. Some mono switches may occurr at the phono stage; others may be implemented at the line stage. They would behave differently.
Here's a thread about preamps with mono switches in general. And here's a thread about a specific circuit design at the phono stage that does the things you were talking about such as noise cancellation.
However, note that these are not features you can just go out and buy. The first thread mainly addresses vintage classic items (such as an Audio Research unit) that would cost a lot on the vintage market. The second thread addresses a design that probably has to be custom-ordered and handbuilt.
Then there's the third alternative, particularly the cartridge that started this thread. The Audio Technica unit is a high output (1.2mV) moving coil cartridge, true mono with a -30dB rejection in the vertical plane, and it's readily available for anything from $112.65 to $299.99, depending on the vendor you choose.
Furthermore, if your System profile is up-to-date, I see you have a Kenwood LM07 turntable, which has a universal headshell. You could get the Audio Technica AT33MONO/LP and a headshell, mount and align it, and just play the mono records in native mode. It's much easier than hunting down a phono head with mono switch, and the results would be at least as good.
I'm really happy with that cartridge and it has increased my enjoyment both of latter day mono reissues (Beatles, Beach Boys, Nat King Cole, Gene Krupa) and digging out 45-60-yr-old mono original pressings. Highly recommended.