I just put 3 arms on a single plinth made for 2 arms and learned a lot doing it. You can see it here, 8th photo:
https://systems.audiogon.com/systems/9511
How much room do you have? (verify clearances inside the closed dust cover for height and rear part of the arm when at rest). I got lucky with my long arm’s height after I put it on a spacer, and was very careful to find a compact arm on the left, I just squeezed it in.
you have some options you might not have considered.
What diameter is the existing hole?
You can elongate the hole ’some’ as long as the new arm’s cover plate will cover the larger oblong hole, that gives you flexibility within reason. I did that for my rear arm (check underneath for any obstructions and clearance to fasten the replacement arm).
You can add a larger cover plate (or very large washer) below an arm’s base plate (thin and strong) to cover an elongated hole below the replacement arm IF you will be able to keep the arm low enough for proper VTA.
Note: my thick Victor TT81 sits above the plinth, I had to add a 3/8" spacer under the base plate to get the arm high enough. Clear acrylic, I could have painted it black, didn’t bother. 7th photo
Previously I had 3/16"thick rectangular hardwood board below the base plate that I stained to match the plinth. Then the tonearm supplier sent me the spacer pre-drilled for the base plate screws when he saw my TT81 thickness.
Oh yeah, I filled an old hole with a wood plug from the bottom, left it recessed a bit, and put a 45 adapter in it.
Clever, with caution!
https://systems.audiogon.com/systems/9511
How much room do you have? (verify clearances inside the closed dust cover for height and rear part of the arm when at rest). I got lucky with my long arm’s height after I put it on a spacer, and was very careful to find a compact arm on the left, I just squeezed it in.
you have some options you might not have considered.
What diameter is the existing hole?
You can elongate the hole ’some’ as long as the new arm’s cover plate will cover the larger oblong hole, that gives you flexibility within reason. I did that for my rear arm (check underneath for any obstructions and clearance to fasten the replacement arm).
You can add a larger cover plate (or very large washer) below an arm’s base plate (thin and strong) to cover an elongated hole below the replacement arm IF you will be able to keep the arm low enough for proper VTA.
Note: my thick Victor TT81 sits above the plinth, I had to add a 3/8" spacer under the base plate to get the arm high enough. Clear acrylic, I could have painted it black, didn’t bother. 7th photo
Previously I had 3/16"thick rectangular hardwood board below the base plate that I stained to match the plinth. Then the tonearm supplier sent me the spacer pre-drilled for the base plate screws when he saw my TT81 thickness.
Oh yeah, I filled an old hole with a wood plug from the bottom, left it recessed a bit, and put a 45 adapter in it.
Clever, with caution!