[Jo-Vo]

Hello!

I've got a Dual 505 turntable but its cable is broken. Also the ground wire seems to "die" soon. So I want to open the turntable and solder new RCA/cinch cables to it. What type of cable (for audio and ground) do I need and is there anything I have to keep in mind?

Thank you!

Regards,
Jonas

 

[HiGHFLYiN9]

I'd imagine the wire runs directly from the tonearm to the RCAs, and they are likely 28 gauge (very thin). It's a very delicate process to rewire the tonearm that can take a few hours to complete. You may want to post in the DIY section for suggestions on how to go about the process.

 

[memepool]

Presuming your'e talking about the external cables rather than the internal tonearm wiring?

If I remember rightly if you open up the 505 you find that there is a circuit board under the platter which the lead out cables are wired to. It's a bit annoying to remove the platter as there is a little plastic disc at the centre next to the spindle which you must rotate in order to release it and this takes a bit of detective work without the manual.

The best quality external cable for this is common or garden XLR microphone cable. You will often find fancy audiophile interconnects these days are high impedance which isn't any use for a very weak signal like this.

Go to somewhere like Thomann or a Pro-Audio shop and look out for names like Mogami, Belden, Van Damme, Sommer and Klotz. Neutrik RCA plugs are pretty cheap. You can use any old bell wire for the ground and it's a good idea to solder a spade to the end to stop it unravelling although not strictly necessary.

For internal tonarm wiring the cheapest solution is actually to get an old computer mouse and strip the connecting cable. It's very high quality fine gauge copper perfect for a tonarm but it is a very tricky process as mentioned. Not sure I'd even attempt that with a tonearm like the ULM Dual.

 

[Jo-Vo]

Hello!

Thank you for the replies!

Yes, I want to attach a new /external/ cable, no recable of the tonearm needed.
So the first thing I have to look for is low impedance?
At Thomann I can choose between Sommer and Cordial (german manufacturer) cables. I use many Cordial microphone cables for home recording (nothing negative to say about them) but if you recommend Sommer I'd buy them even if they are a bit more expensive.

Regards,
Jonas

 

[memepool]

Quote:

Originally Posted by Jo-Vo /img/forum/go_quote.gif I use many Cordial microphone cables for home recording (nothing negative to say about them) but if you recommend Sommer I'd buy them even if they are a bit more expensive.

Not at all Cordial is fine I'm sure. It's just not living in Germany it's a brand I havn't seen anywhere but Thomann whereas Sommer are more famous probably hence the price hike.

I've not tried the Cordial but if you have good experience using it with mics then it'll be absolutely fine for a turntable and a great deal better than the old Dual cable.

 

[Jo-Vo]

Hello!

I'm sorry for activating this old thread again.
I bought a cable but it has got 2 cores and a screen so I don' know which to use for my + and - of the turntable's signal. I don't know how to describe it, I'm sorry. Thank you!

Regards,
Jonas

 

[memepool]

Hi if you look at where the wires come out of the bottom of the arm there are 4 or 5 usually.
These are

red +
white -
green + earth
blue - earth
black arm tube earth

So in effect a balanced configuration the same as XLR.

So to wire to phono plugs the earths go to the sheath and the lives go to the tip.

the black tonearm earth goes to a separate earth cable which runs to the casing of you pre-amp.

 

[Jo-Vo]

Hi!

Thank you for your reply!

Which cables are for right, which for left signal? There isn't anything about that in your "table", is it? Hm, maybe I understood it wrong. Or did you change L/R to +/-?
I'm a bit confused, sorry.

Quote:

So in effect a balanced configuration the same as XLR.

So if that is the case I have to reduce that to unsymmetrical RCA/Cinch-Connection?

My original question was (I'm sorry for explaining it really bad):
If I have 2 poles looking at the phono plug and 3 poles (2 cores and 1 shield) looking at my cable, which poles to use in the cable? The 2 cores or one core and the shield?

Oh, maybe I should post this in the cable section also, hm.

Regards,
Jonas

 

[memepool]

Quote:

Originally Posted by Jo-Vo /img/forum/go_quote.gif Hi! If I have 2 poles looking at the phono plug and 3 poles (2 cores and 1 shield) looking at my cable, which poles to use in the cable? The 2 cores or one core and the shield?

+ = right
- = left

you can either wire both the minus and shield to the shield of the RCA plug and the plus to the tip or you can just not bother with the XLR ground cable at all and just use the two cores for +/- as above.

 

[Ori]

Quote:

Originally Posted by Jo-Vo /img/forum/go_quote.gif My original question was (I'm sorry for explaining it really bad): If I have 2 poles looking at the phono plug and 3 poles (2 cores and 1 shield) looking at my cable, which poles to use in the cable? The 2 cores or one core and the shield?

You seem to be confusing terms.
The CMTOP222 cable is a single twisted pair with a shield (plus a conductive plastic layer). You will need one run per channel.
For each channel, connect the LIVE (+) wire to the red wire and RETURN (-) wire to the blue wire. Connect the shields to a seperate GROUND wire at the turntable. I'd try to not connect the shields diretly to the RCA barrels. If there is no hum then that it the prefered configuration.
If there is hum then try soldering the shields to the RCA barrel through a 1K resistor. This will avoid ground loops and hopefully will give you a "better" ground.

 

[Jo-Vo]

Hello!

Thank you for the replies!
I think I know what to do now.

Well, I planned to use one cable per channel but maybe I didn't write that clearly. It's not easy for me to describe all that stuff with the correct technical terms since I am not a native speaker.

Maybe I just should have opened the turntable before asking all that stuff but I just wanted to be prepared for the "big moment" since it would be nice to open it, do the soldering and close it right after that. I hope that it will work and I'm going to tell you about my results.

I'll try it this way and then the method with the ground to the RCA. What does the resistor do?

Thank you!

Regards,
Jonas