SME 3009 S2 Improved wiring question

[Audio Garage]

I’ve recently acquired a Garrard 401 and SME 3009 S2 improved tone arm. The original tone arm cable and plug is missing so I’m considering extending the tone arm wiring to RCA connectors, and ground post, to be located on the outside of the decks plinth. So the questions are:-
1. Is there any technical reason this should not be done, like extending the length of the wires, capacitance issues etc?
2. Any recommendations on suitable wires to use?
3. Anyone come already come across any kits to do this?

 

[tnsilver]

Welcome to AK!

Can do but only extend the TA wiring to your turntable RCA sockets so you can use any phono cable of choice later. Cardas 33 AWG OFC Litz is what I use. Ground wire goes on any metallic part of the TA mounting plate.

No need for a kit, but if you check the auction site you'll find Cardas wire with headshell connectors attached already.

 

[biscuithead]

I’ve recently acquired a Garrard 401 and SME 3009 S2 improved tone arm. The original tone arm cable and plug is missing so I’m considering extending the tone arm wiring to RCA connectors, and ground post, to be located on the outside of the decks plinth. So the questions are:-
1. Is there any technical reason this should not be done, like extending the length of the wires, capacitance issues etc?
2. Any recommendations on suitable wires to use?
3. Anyone come already come across any kits to do this?

This is done quite a bit. I’ve done it dozens of times. I just use the existing solder terms to extend to where I mount the RCAs. I use 18 gauge silver wire, I cut the 4 pieces exactly the same length and manipulate and insulate as needed.

 

[tnsilver]

I use 18 gauge silver wire

18 guage wire is more appropriate for speaker cables. Each is over 1mm in diameter, and there's 4. Are you sure about this?

 

[biscuithead]

18 guage wire is more appropriate for speaker cables. Each is over 1mm in diameter, and there's 4. Are you sure about this?

This is just the ~6” piece that goes between the tonearm cable interconnect, and the RCA backs.
18awg is what I have so I use it.
It can be 24awg and work fine also.

 

[biscuithead]

Oh, OK then, thought you're talking about TA wire.

I really like to be able to plug into the back of my TTs with whatever cables I want to. The only tone arm/table I haven’t touched is a Jelco on a TD124, the armboard overhangs the plinth so accessibly is easy.

 

[bimasta]

Great combo, Mr Garage!

I've bypassed the old SME connector, and twisted/soldered my exit cables directly to the internal TA wiring. Thus there's only one solder-joint between cartridge output pins to preamp inputs. Any connector, whether the old 4-prong SME or newer RCAs, adds 1 more solder-joint and 1 metal-to-metal plug-joint to each of the four leads from the cartridge. The most direct signal path, with the least breaks, is the best way to preserve the small signals from a cartridge, especially low-output MCs. IMO, it surpasses any 'advantage' to be gained by using 'better' cables, at the cost of adding more solder and plugs.

Cardas 33 AWG OFC Litz is what I use.

@ Tnsilver — I'm about to rewire an arm with the same Cardas wire you mention, the version with it's own shield. It's a single very thin (2mm) cable containing 2 x twisted-pairs of L and R leads, a braided shield, and black outer insulation. Cardas tells me it can be used for a single continuous length, including the exposed ±meter from the TT to the preamp — without hum from RFI or EMF et al. But I'm dubious.

Have you any experience with this pre-shielded version, Tnsilver?

 

[tnsilver]

Have you any experience with this pre-shielded version, Tnsilver?

Sure I do. You're talking about this:

with this shielding:

and this teflon masking:

I have fallen for that Cardas promise twice b/c I figured it's a tonearm wire. It's probably not. That harness, while very good for shielding and with superb conductivity and very low capacitance, is too tough for free twisting and hindered my TD-135 tonearm (BTD-12S) lateral movement and did the same with my SME 3012 rewire. It simply doesn't twist that welI. I ended up scraping the black insulation off, cutting the silvery shielding off with a pair of scissors and leaving the 4 strands in their teflon masking. I never buy it anymore for TA rewiring, just the none-shielded alternative, which is pretty much what I ended up with after the aforementioned treatment of the shielded harness. If you wanna use it outside the tonearm - it's perfect for that.

Now I only use this:

which gives me this ~22pF capcitance for the length (about 50cm):

and a little over a 1/3 of an Ohm resistance

 

[sgmlaw]

Great combo, Mr Garage!

I've bypassed the old SME connector, and twisted/soldered my exit cables directly to the internal TA wiring. Thus there's only one solder-joint between cartridge output pins to preamp inputs. Any connector, whether the old 4-prong SME or newer RCAs, adds 1 more solder-joint and 1 metal-to-metal plug-joint to each of the four leads from the cartridge. The most direct signal path, with the least breaks, is the best way to preserve the small signals from a cartridge, especially low-output MCs. IMO, it surpasses any 'advantage' to be gained by using 'better' cables, at the cost of adding more solder and plugs.

@ Tnsilver — I'm about to rewire an arm with the same Cardas wire you mention, the version with it's own shield. It's a single very thin (2mm) cable containing 2 x twisted-pairs of L and R leads, a braided shield, and black outer insulation. Cardas tells me it can be used for a single continuous length, including the exposed ±meter from the TT to the preamp — without hum from RFI or EMF et al. But I'm dubious.

Have you any experience with this pre-shielded version, Tnsilver?

tnsilver has it correct here. For tonearm wiring, I have found that, especially in the lower mass arms, lighter and thinner is better. I don't care for shielded wire in the actual tonearm for that reason. When I redid the Series III I presently use, I went with Cardas unshielded, straight out to the plinth jacks. I forget the gauge, but it was absolutely 30 gauge or thinner. Big improvement over the original wiring and it presented less of a torsion load as well. If you loop it through the joint correctly, it will not fatigue (ours has swung back and forth for 20 years across countless albums with zero problems). And if you route it correctly, you will not pick up anything off the deck internals. Tedious to work with, but well worth it.

 

[bimasta]

Thank you both, Tom and Mr Law. I wasn't planning to use the shielded all the way through, because of the 'twisting' issue Tom raised. I'm stripping it down to the 4 thin leads to go inside the armtube/post, and only using the complete cable for the exit leads — which you seem to endorse:

If you wanna use it outside the tonearm - it's perfect for that.

Also, my cable does not have the Teflon mask your pic shows, Tom... but I bought it back in '04, maybe it was added later.

I'd like to see double-shield (braid+foil) but of course that would cause even more interference with flexibility.

BTW, I got this reply from Cardas:

" We use litz copper conductors and therefore every strand of copper used to make a single conductor has a clear coat to protect it from aging and oxidation. This coating requires a special termination process and tools. We use a solder pot to burn off this clear coat and tin the ends of the conductors. Without a solder pot it is difficult to tin the wire but the smaller sizes like 33 AWG can be done with a hot iron."

Is this how you do it? Solder pot? I asked if I could burn it off with a flame (eg butane lighter) and they said no. I don't have a solder pot. I did try a lighter, and it seems to work....?

 

[Blue Shadow]

The tonearm, most are some electrically conductive material would be the shield on a rewire. The arm is grounded to drain whatever it pics up. I used a chunk of that Cardas shielded to jump from the tonearm connector to the RCA cable which on a Magnepan arm is designed to be attached to the turntable base. The jumper is needed to allow the floating suspension to work without a heavy RCA Cable attached. Sure the use of RCA jacks on the tt base would allow lightweight wiring to be used to those jacks. I would use shielded after the wiring leaves the tonearm.

 

[Blue Shadow]

I wouldn't use a flame, I would build a solder pot for 33ga wire. What that means is a small puddle of solder on something that won't burn. Not like you are going to do a lot of them. A drop of solder on the tip of the iron might even be enough.

 

[tnsilver]

Is this how you do it? Solder pot?

No. I never liked heating stuff up to more than water boiling point. I have a melting pot and a bunsen burner, but I'm not using it. I use a soldering iron. As far as I can tell, Cardas coats their wires with cellulose, so it's no big deal to scrape/burn off.

 

[sgmlaw]

No. I never liked heating stuff up to more than water boiling point. I have a melting pot and a bunsen burner, but I'm not using it. I use a soldering iron. As far as I can tell, Cardas coats their wires with cellulose, so it's no big deal to scrape/burn off.

My recollection is that I did it roughly the same way. Practically speaking, wire much thinner than 24-26 gauge, unless you are using a specialty tool, is practically impossible to mechanically strip bare without causing some conductor damage, however slight.

My only quibble with the melting and burning that even Cardas advocates, especially with more synthetic insulators such as teflon, is keeping the residue from contaminating into the final solder joint. But one can only worry so much about these things. If the final connection tests out at true zero resistance, you have done the job.

 

[bimasta]

at which point it becomes a super-conductor and levitates... into the stratosphere.

Music of the Spheres! Step-by-step instructions to achieve this, Tom! ASAP!

 

[Audio Garage]

All....Thanks for the input you have allayed my fears and I will proceed with this project in the New Year. But first building a replacement plinth and that’s a whole new discussion on materials and isolation