TT prloblem

Jonesy

I've tracked the intermittent humming that was coming from the left channel down to the left output of the TT (Dual 1246). It will go away if I mess with the left output jack and it moved to the right side when I switched the left output to the right side. The outputs are garden-variety RCA's and they go directly into the player (i.e. no connection point on the TT). I am thinking about repairing this myself, or with my brother-in-law's help as he's a whiz with a soldering iron.

Would you experts recommend replacing just the jacks or should I replace the whole wire? I haven't cracked the base yet to see what's what in there but it can't be that bad. Any recommendation on replacement parts? I just got this thing and know very little about TT's. I'd hate to mess something up or go over board on replacement parts. It was bought used for $80 so I'm not going to put $100 cardas jacks or something ridiculuos like that on it. Although something more substantial than the generic ones that are on there now would be a good idea I think. Any help is appreciated.

[Deleted User]

Hello,
It's been a while since I've looked "under the hood" of a Dual turntable, but I believe they used a terminal strip to provide a connection point for the wires that come down from the tonearm. So, you'll see four very small wires coming from the pivot point of the tonearm. These wires attach to a terminal strip, then shielded coaxial wires are connected to this same terminal strip. This, then becomes the right and left RCA connection cables. Since you'll be hard pressed to replace just the RCA connectors, on the stock cables, you might want to consider replacing both RCA cables with a more recent, better sounding pair of interconnects. You'd have to remove the original cables and cut the RCA plugs off the new ones. Then solder the replacement cables to the terminal strip inside the turntable. Things should sould better with new interconnects and no humming.
Regards, Ken

Jonesy

I take it the connection to the terminal strip is a solder joint? Thanks for the info, it's exactly what I was looking for. Any recommendations on cable and RCA types?

[Deleted User]

Hello,
I believe the Dual is a soldered connection, I seem to remember Garrard as being female RCA plugs, You'll have to cut off the RCA connector and strip off 1/4" of the outside insulation, this will expose the braided shield underneath. Use a small tool to un-braid the shield so you can twist all of the braid wires together. Then strip off 1/8" of the smaller insulation exposing the core wires. Then these are tinned and soldered in place of the originals.
Most moving magnet or moving iron phono cartridges are somewhat sensitive to capacitive loading. The total amount of capacitance will depend upon the tonearm wires and the length of the cable you plan to use. To do it properly you would need to know what the capacitance requirement is for your cartridge and determine what the capacitance per foot is for the cable you want to use. This might be beyond the scope of this project, so as long as you keep the connecting cable as short as possible you should be fine. You'll start to roll off the high end if you use a cable much longer than 3'.
Good luck!
Ken