can I turn my stereo amp to mono- is there a way

Kr4...Could be. Of course if you want to play 78 rpm records you need a different diameter stylus as well.

Not all. I believe the Lyra mono is a specialised design.

Kr4...The so-called "Mono cartridges" that they sell today are, I'm told, nothing but a stereo one with the Hi terminals strapped. (Which was my last suggestion).

Eldartford wrote: Kr4...He needs to go mono because of the LF noise of vertical groove modulation, which has no signal, except the noise.

Then he needs a mono cartridge.

Kr4...He needs to go mono because of the LF noise of vertical groove modulation, which has no signal, except the noise.

A jumper from TAPE OUT LEFT to TAPE OUT RIGHT might woek as you suggested, and would be the most easy. If not, use two Y-interconnects, 2 to 1 plugged into a 1 to 2, connected from TAPE OUT to TAPE IN, and select the TAPE input. You will need to get male and female connectors or coupler, as required.

Better yet, put a short across the HI wires from the stereo phono pickup. You could tack solder this across the phono input jacks of the amp, or even put a switch in to give you stereo/mono selection for the phono input.

Does it have a tape output? Many of these are unbuffered and an interconnect from the R to the L will mono the amp.

Of course, if the LPs are already mono, why do you need it?