Technics 1200 mk2 captive cable replacement

[klamsoss]

I jumped on the bandwagon a while ago and got myself a 1200SL mk2. I'm quite happy with it. It was gently used and I have refurbished it with everything available from KAB except the arm damper. With the upgraded tonearm wires, replacement thrust bearing, wax kit, and external power supply, this thing is great.

Sadly, I retained the original stock cables for a long time because other projects got in the way, and I couldn't figure out how to route new captive cables in a way that was satisfactory to me. While discussing the issue at work, my buddy suggested I bring in the disc that covers the captive cable interface on the underside of the unit. The issue is that anything other than the flimsy stock cord doesn't play nicely with the strain relief clamp (which doubles as protection for the cables as they pass through the metal plate below the tonearm.

2 days later I brought in the plate:
"hell, man... this ain't nothin. What size cables you want in there? I'm gonna use the plasma table and cut you out a plate that has a pass thru. We'll get you some rubber grommets to keep the cables nice and you'll be in business."

A week later (two weeks ago), he brought me a prototype, as pictured next to the stock metal plate. I gave him the OD for Belden 1505F because that's the stock from which I have Blue Jean make my cables (with connectors I supply). The purple is shown in the attached photo for contrast. Those cables are destined for an AR my dad will have soon.
He cut out the disc no problem and plasma etched the locations for the mounting and alignment holes. Those were then drilled out using a drill press. The holes for the cables themselves were plasma cut, not just etched. He said for the future, he can get them a little smoother. We threw in some grommets sized 5.57x7.94mm and they hold the cable very snugly, but not so tight that it's impossible to push the cable through. It's a pretty dang good piece of kit, if you ask me.

Stay tuned for installation pics. Working on it now.

 

[klamsoss]

Removing the old captive cables is pretty straightforward. Take off the black rubberized base of the turntable by unscrewing the feet, then the 20-25 other Philips screws (If you have handled an SL-1200 then you know what I'm talking about). There are 4 screws on the plate that the ground and signal cables go into. All 4 come off, but don't lose them. Remove the strain relief clamp from the captive cables. Clip the zip tie holding the old cables to the circuit board, and desolder.

To put the new cables on, I started by putting the grommets in place on the new plasma-cut pass-through plate (see the picture of the undressed purple cables started into the grommets from my first post here). Feed the new cable through enough to be able to do your soldering. For practical reasons somewhat unique to me, I terminate my phono ground cables in a thin blade connector. That was easy to feed through one of the grommets that already had a signal cable in it.
I soldered the new BJC Belden 1505F cables to the circuit board. Not my cleanest job but it's more than adequate. I zip tied the cables to the board to relieve strain on the solder connections themselves (same as the original ones were). Then came the sort-of-but-still-not-that-hard part. Positioning the 1505F cable was a little tricky inside the shielded portal, but the cable has enough flexibility that it wasn't too bad. I don't think the LC1 would work. I just wiggled things around and worked the cables through the grommet until the plate was oriented over the guide pins, and then tightened up the two mounting screws (which I totally lost, but then found again after reassembling the whole thing using replacement screws).

As for the plate, it seems like it a really good way to ensure shielding at the connection and cable integrity as signal exits the shielded area. It also has a nice clean look. If I had him do it again, I would move the holes on the plate a bit so the wires come through closer to the center of the hole in the rubberized base.
If anyone is interested, message me and I'll see if he wants to make a few more.

 

[mcgjohn]

@klamsoss , KAB makes a output mounting board for phono leads. Why not install that then you can use what ever interconnects you feel like as long as they are shielded.

Would also suggest the arm dampener, makes quite a significant improvement.

 

[WaynerN]

I replaced my cables with RCA jacks. This way, I can use whatever style or length of cable I want.

 

[klamsoss]

I didn't want to add another set of contact points by using a set of RCA jacks. That's two additional connections between the cartridge and the amplifier that really aren't necessary. If that's something someone wants to do, that's cool, but it is not a route that makes sense to me. I don't really care about cable swapping (been there, done that) and I have been very happy with the quality of the Belden 1505F BJC that I have throughout my system. They do everything I need them to do, including not draining my wallet (which I have never found expense to be directly correlated to improvement in sound quality).

SO... do what you like. If fiddling with a bunch of different RCA cables is your thing, GO for it!
Since I like to listen to my turntable and not just stare at it and play with it, it makes sense to just have captive cables. Looks good, sounds good.