REALLY quick but important question on recabling my turntable... need answer ASAP!

[003]

I am in the middle of recabling my turntable RIGHT NOW as I speak, the iron is already hot and I can not move forward until this question is answered.... This is a very simple question that anybody in the DIY forum should know, though so I am faithful I will get the answer relatively quickly.

So here it is. I am recabling my turntable, with both a new power cord, new ground wire and new RCA cables (that you hook up to the phono stage).

About the RCA cables. Note I am not talking about the thin tonearm wires. The RCA cables that were in the turntable stock were divided up into two wires, left and right, of course. If you cut one of these wires open, you were greeted with a whole ton of thin silver wires, I assume the shielding. When you cut through that, you were greeted with a smallish insulated (with rubber) wire in the very center. If you cut through this one you are greeted with more thin silver wires, the signal wires.

If you carefully cut off the plastic around the RCA plug, and looked where each of these two wires was connected, you will see that the center wire was soldered to the conductive RCA pin and the lots of thin silver wires (the shielding) was twisted into a single wire and soldered to the outside ring of the RCA plug, I assume the ground.

Now that you know what the stock RCA cables are like, let me explain the ones I am replacing it with. I am replacing it with a 3ft Acoustic Research performance series stereo interconnect, which I am GUESSING is shielded AND grounded, where as the stock turntable cables use an external ground wire. That is what I would like to do here as well, but inside the AR cable, are 3 wires. I know which one is the signal, but I do not know which one is the ground and which is the shielding. I need the shielding, as I will not be using the ground. For reference, here is a link to the AR cables:
http://www.amazon.com/Acoustic-Resea.../dp/B00008VSI7

So inside the AR cable, from outside to in, is a layer of what looks like rubber and layer of mylar shielding after that. Inside the mylar shielding is where everything important is. There is a thin red wire, a thin white wire and a bunch of thin silver wires without any insulation, but it is not wrapped around anything like in the stock cables, they are all in a group. And in between all these things is what looks like cotton, not sure for what. All I know is that the red wire is the signal wire. If we look at how these 3 wires are soldered to the RCA plug, I found that the red wire was the signal wire (already knew that), and the white wire and the non-insulated silver wires combine and are soldered to the outside circle of the RCA plug, which is the ground I think. [size=small]Anyway, what I need to know is, when replace the stock cables, do I substitute it's wrapped around silver wires with the white cable, or the non-insulated cable (many smaller cables in a group)?[/size]

Also, one final quick question about replacing the power cable. I want to replace it with a polarized one, because the stock one is not polarized. The stock power cable is soldered to two solder spots (one for each prong), and then there is another cable soldered to each solder spot as well, these go into the motor to power it. One of these cables is red and one is white. [size=small]Do I solder the polarized side (with the bigger prong) of the new cable to the solder spot with the red cable or the white one?[/size]

Thanks for the help! I need the answers as quick as possible because as I said I'm doing this right now!

 

[003]

Come on guys I know somebody knows the answer to this!

 

[platenspeler]

Quote:

Originally Posted by 003 /img/forum/go_quote.gif Come on guys I know somebody knows the answer to this!

Hi,

Just in case your soldering iron is still smokin'

Regarding the RCA/microphone cable it seems to me that you have a balanced/symmetrial type of cable. Normally these are connected red for signal and white for signal return. The shielding is connected only on one side to the white cable (to avoid ground loops).

In my opinion, it doesn't even matter whether or not you connect the shielding to the signal return, but normally one does (on one side only).

See also: the van den Hul website at http://www.vandenhul.com/artpap/wiring6.htm

Regarding the power cable: ?????? Might be I do not understand your point but expect it really doesn't matter. In the type of turntables I use (I have 2 Thorens and one Clearaudio) it really DOESN'T matter what polarity you use as there is NO connection between the signal/tonearm part and the motor. But of couse your situation might be different....

regards,

Maarten

 

[003]

Ok so I'm confused. I want to hook this up the best way possible, even if it won't make a difference. I am just anal like that. I have a question. The cable is balanced now that you mention it, on the cable it says "Directional balanced line audio cable". I really want to know the "proper" way to hook it up to the turntable, even if the "proper" way will be no different from the "improper" way, I just have OCD about stuff like that. The red wire hooks up to the live signal (+), and the white wire and shielding hook up to the negative grounding part, correct? Or do I just not use the white wire in this case, since these will be the output cables for the turntable, why would you use a return cable?

Also, I am aware the polarity will make pretty much zero difference, but again I have OCD about this! On a technical only level, should the polarized wire (the larger prong) be hooked up to the red or white wire?

 

[threEchelon]

Is the new cable triaxial or shielded twisted pair?

Why do you need to change the power cord? What's wrong with it?

 

[003]

I know the interconnects are not the best choice, but they will work fine. What is the best way to hook them up?

I am changing the power cord just to be thorough. I KNOW polarity won't have an effect on anything. But IF IT DID, would I hook the polarized side up to the red or white cable?

 

[nikongod]

there are 5 "sound" connections in most turntables.
2X "in phase"
2X "out of phase"
1X ground.

hook one each of the 2 wires in the new cable to in and out of phase for each channel. the "in phase" wire goes to the tip of the RCA, the "out of phase" goes to the shell of the RCA. if you noted what was connected where with the old stuff, hook it up. otherwise, you will have to check colors on the cartridge clips and the like.

twist up a bit of the shield and hook it to ground in the table. DO NOT!!!111 hook the shield to the shell of the RCA. you will still need a connector for ground on your preamp or somewhere.

i guess you could debate weather ground is a sound connection, but i hear all sorts of unfriendly sounds when it slips out of my phono-stage's ground "connection."

 

[platenspeler]

Quote:

Originally Posted by 003 /img/forum/go_quote.gif I know the interconnects are not the best choice, but they will work fine. What is the best way to hook them up? I am changing the power cord just to be thorough. I KNOW polarity won't have an effect on anything. But IF IT DID, would I hook the polarized side up to the red or white cable?

I had a quick look on the web but could not find whether your turntable motor was AC or DC. But even if known still the polarity of the motor doesn't matter since it is not electrically connnected to your arm and cartridge. Oil and belt make a difference, but polarity not, the motor won't see it.

Since you are determined about it, just switch a few times and determine which position sounds best to you and mark it. In the Netherlands and in more European countries the power plugs can be plugged both ways and I know people, especially with tube amps, experimenting a lot with polarity mainly because of its possible influence on enclosure potential and earth etc.

Regarding the RCA cable. I personally think that using a balanced cable (like your new cable) is better than an unbalanced cable for phono applications. Just connect red to signal and the white to signal return and do so for both channels. connect the metal shielding only on one side of the cable to the white one. So either inside you turntable or at the other end inside your RCA plugs. I prefer at the side of the amp (=in the plugs).

Make sure you connect the seperate earth/ground cable, should you change it too, exactly to the same place where the old one was too.

I do think you cannot go wrong except when you want to improve on the original other than just replacing. Signals are so weak (2mV for MM, 0.2V for MC cartridges) that you have to be careful not to introduce humm. So do not connect wires to other places in the chassis but follow the design of the original builder. This includes not making a turntable earthed when the original design did not use earth. You can use shielded power cables, but do not connect earth somewhere (motor) in the turntable if the original design did not require it (I mean safety earth here, not the ground wire that is connected to your amp).

Of course there is another way of improving your cables. As you can see on my homepage I connected RCA connectors to the back of my Thorens turntable. his way I can swap some standard RCA cables just to experiment with the sound.
In any case, I'd spend the most of my money on the interconnects and not on the power cable.

regards,

Maarten