Some of the stereo arms had four wires up to the cart, but one was cut short and folded back. Depending on how flexible after washing, i often replaced them as part of the conversion to magnetic.
It is best to avoid any ground loop especially in these high-gain such as with magnetic carts. A form of loop occurs with the cables that come from the arch where both grounds go to one pin and then come together again at the amp. This didn't matter with the high output from the ceramic cart, but does result in a slight hum when using a magnetic.
Ideally, the four pins should remain separate till they reach the amp itself.
RobNYC
On Saturday, August 5, 2023 at 10:06:17 PM GMT-5, Jay Hennigan via Jukebox-list jukebox-list@lists.netlojix.com wrote:
On 8/5/23 15:01, Shankar Singh via Jukebox-list wrote:
Should these models of tonearms have 4 wires, 1 for each terminal? Or can the 2 (-) close to the cartridge end be connected to each other, so that 3 wires are used in the tonearm?
Some of the earlier cartridges have a common ground terminal, hence three wires. By the time of the 3300 they probably used all four. If I recall correctly the grounds are connected together at the 4-pin Eby plug on the arch.