I have been wrestling with this issue myself. I have been testing out several options for playing old mono LPs and 78s. I thought that I could be smart and use a single TT for both; either by using a single arm w/ removeable headshell or using a deck with two arms. Well, I was wrong - or at least I can say that it is not working out to my expectations.
I have come to the conclusion that to really play 78s to the best of their ability reqyires a dedicated TT and arm/cartridge combo. The deck needs to be heavy - really heavy, as does the weight and tracking force of the arm and cartridge. Also, tight-fitting spindles and more especially weights/clamps are detrimental; I believe because they are coupling the (quite resonant) shellac record to the deck.
I have ended up using an old Rek-O-Kut deck and Grado arm for 78s, and I think that it sounds pretty good. Now we can have a discussion about phono stages for 78s...
I have come to the conclusion that to really play 78s to the best of their ability reqyires a dedicated TT and arm/cartridge combo. The deck needs to be heavy - really heavy, as does the weight and tracking force of the arm and cartridge. Also, tight-fitting spindles and more especially weights/clamps are detrimental; I believe because they are coupling the (quite resonant) shellac record to the deck.
I have ended up using an old Rek-O-Kut deck and Grado arm for 78s, and I think that it sounds pretty good. Now we can have a discussion about phono stages for 78s...