I've been using Mogami ultra-flexible miniature cable to wire my tonearm: https://mogamicable.com/category/bulk/ultra_flex_mini/
Specifically, the 2490-08, which is a two-conductor #32, with shield. I use the shield as the ground for both channels.
Obviously, leaving the shield and jacket on the loop from the pivot to the plug imparts some resistance/torque to the arm moving. It is fairly linear for such a small arc, though, and my wire hops off the wand at nearly the top dead center of my pivot, which minimizes the influence. I've measured the force imparted by the wire and simply compensate by using it as part of my anti-skating force,
I've tried other cabling arrangements where the loop from the pivot to the plug isn't shielded but rather twisted (substituting a third, insulated, conductor for the shield). I prefer the level of noise rejection I get with the all-shielded wiring.
Some of the higher-end unipivot arms out there seem to use some sort of a sleeve on the tonearm wires where they exit the wand and travel to the plug/jack, and I wonder if there is a super-flexible sleeve that provides some EMI/RFI rejection? I've looked at braided copper sleeve and it seems pretty stiff.
Basically, I'm looking for suggestions for improving this aspect of my arm. I've seen alternative shielded wiring from outfits like Daburn, this wire is even smaller than the Mogami. The Daburm is less than 1mm for the two-conductor #40, versus 1.7mm for the Mogami. I'd love to try some but the minimum order seems to be a rather expensive spool of the stuff (hundreds of US dollars). if anyone knows how to get Daburn cables by the foot, I've love to hear about it.
As it is now, I have no problems with extreme tracking. I have cartridges rated for 100um @ 1g and I can certainly hit that no problem. I just feel there is room for improvement here.
I've included a picture so you can see how my arm is wired, and the loop I'm trying to optimize.
Specifically, the 2490-08, which is a two-conductor #32, with shield. I use the shield as the ground for both channels.
Obviously, leaving the shield and jacket on the loop from the pivot to the plug imparts some resistance/torque to the arm moving. It is fairly linear for such a small arc, though, and my wire hops off the wand at nearly the top dead center of my pivot, which minimizes the influence. I've measured the force imparted by the wire and simply compensate by using it as part of my anti-skating force,
I've tried other cabling arrangements where the loop from the pivot to the plug isn't shielded but rather twisted (substituting a third, insulated, conductor for the shield). I prefer the level of noise rejection I get with the all-shielded wiring.
Some of the higher-end unipivot arms out there seem to use some sort of a sleeve on the tonearm wires where they exit the wand and travel to the plug/jack, and I wonder if there is a super-flexible sleeve that provides some EMI/RFI rejection? I've looked at braided copper sleeve and it seems pretty stiff.
Basically, I'm looking for suggestions for improving this aspect of my arm. I've seen alternative shielded wiring from outfits like Daburn, this wire is even smaller than the Mogami. The Daburm is less than 1mm for the two-conductor #40, versus 1.7mm for the Mogami. I'd love to try some but the minimum order seems to be a rather expensive spool of the stuff (hundreds of US dollars). if anyone knows how to get Daburn cables by the foot, I've love to hear about it.
As it is now, I have no problems with extreme tracking. I have cartridges rated for 100um @ 1g and I can certainly hit that no problem. I just feel there is room for improvement here.
I've included a picture so you can see how my arm is wired, and the loop I'm trying to optimize.
Hi cgallery,
Quite some time ago, I came across a business on the internet offering shielding in a woven non-metallic sleeve format. What intrigued me was that, the filament was plated. That would make it light and flexible. You will have to do your own search because I don't remember the name of that business.
Sincerely,
Ralf
That was metallized plastic. cannot solder, and tarnishes fast.
Very common in Chinese RJ11 telephone to wall wires.
Use Walkman wire, inner two as L + R, outer as shield.
Cannibalize a cellphone hands free, if you need a short piece of wire.
Very common in Chinese RJ11 telephone to wall wires.
Use Walkman wire, inner two as L + R, outer as shield.
Cannibalize a cellphone hands free, if you need a short piece of wire.
If you can't solder it, use a gas-tight connection.
There are all kinds of ways to prevent metals from tarnishing.
Ralf
I don't recognise you cartridge, so I am not sure if it is MC or MM, which has some bearing on cable requirements.
I gather you want to ensure your tonearm wiring is not degrading the noise floor of your phono input. The easiest way to check this is to find what the noise floor is. To do this remove the interconnects insert screened shorting plugs into your phono preamplifier, then turn the amplifier gain to maximum. This is the noise floor (i.e. the ultimately lowest level of noise) that you electronics are capable of. To be completely accurate instead of shorting the inputs, place a resistor that equals the DC resistance of you pickup cartridge, probably in the range 500-1000Ω for MM or 3-20Ω for MC, but 0Ω is close enough for this test. Ideally you will only hear a very small amount of broadband noise, and depending on your total system gain you may even have to get close to the loudspeakers to hear it at all.
Now replace the interconnects and with the cartridge off the record repeat the test, i.e. turn the amplifier gain to maximum - any increase in noise, buzz and hum compared to the first test is the due to the tonearm wiring, interconnects and/or cartridge.
Any hum or buzz is a result of poor screening, whether in the cabling or in the cartridge itself. In my system there is barely audible noise or hum through the loudspeakers at the ~4m listening position with the system at maximum gain, which is ~15dB of gain above trouser-shaking loud for a typical record anywhere in the 9m x 11m listening room. (The relevant parts of the system are: Dynavector XX-2 Mk2 MC cartridge, Rega RB300 tonearm, Cardas Clear tonearm cable, Cardas RCA interface, Canare GS6 interconnects with Canare RCAP connectors, Accuphase E-303x integrated amplifier with built in MC head amp, Tannoy Ardens)
Two comments on a shared screen as the ground for both channels: firstly the shared screen will introduce some crosstalk between channels; secondly RFI/EMI draining from the screen can also be introduced into the phono preamplifier input. In both cases this is becasue current needs an emf to flow and emf = voltage drop; the left channel input cannot discriminate the voltage drop added in the return conductor (shield) that is caused by the right channel, and visa versa. Likewise if EMI/RFI is being picked up on the screen and drained to earth at the phono input, the voltage drop caused by this current is added to the signal "seen" by the input of the preamplifier. Best practice is to have the screen separately shunted to ground, at least for the part of the wiring that has high resistance which is the fine tonearm wires. That's why most turntables have a seperate ground wire.
I gather you want to ensure your tonearm wiring is not degrading the noise floor of your phono input. The easiest way to check this is to find what the noise floor is. To do this remove the interconnects insert screened shorting plugs into your phono preamplifier, then turn the amplifier gain to maximum. This is the noise floor (i.e. the ultimately lowest level of noise) that you electronics are capable of. To be completely accurate instead of shorting the inputs, place a resistor that equals the DC resistance of you pickup cartridge, probably in the range 500-1000Ω for MM or 3-20Ω for MC, but 0Ω is close enough for this test. Ideally you will only hear a very small amount of broadband noise, and depending on your total system gain you may even have to get close to the loudspeakers to hear it at all.
Now replace the interconnects and with the cartridge off the record repeat the test, i.e. turn the amplifier gain to maximum - any increase in noise, buzz and hum compared to the first test is the due to the tonearm wiring, interconnects and/or cartridge.
Any hum or buzz is a result of poor screening, whether in the cabling or in the cartridge itself. In my system there is barely audible noise or hum through the loudspeakers at the ~4m listening position with the system at maximum gain, which is ~15dB of gain above trouser-shaking loud for a typical record anywhere in the 9m x 11m listening room. (The relevant parts of the system are: Dynavector XX-2 Mk2 MC cartridge, Rega RB300 tonearm, Cardas Clear tonearm cable, Cardas RCA interface, Canare GS6 interconnects with Canare RCAP connectors, Accuphase E-303x integrated amplifier with built in MC head amp, Tannoy Ardens)
Two comments on a shared screen as the ground for both channels: firstly the shared screen will introduce some crosstalk between channels; secondly RFI/EMI draining from the screen can also be introduced into the phono preamplifier input. In both cases this is becasue current needs an emf to flow and emf = voltage drop; the left channel input cannot discriminate the voltage drop added in the return conductor (shield) that is caused by the right channel, and visa versa. Likewise if EMI/RFI is being picked up on the screen and drained to earth at the phono input, the voltage drop caused by this current is added to the signal "seen" by the input of the preamplifier. Best practice is to have the screen separately shunted to ground, at least for the part of the wiring that has high resistance which is the fine tonearm wires. That's why most turntables have a seperate ground wire.
Hands free are 4 wire connectors, L + R + mic.
Use the solid three for signal, and the shield for ground.
If weight was not an issue, use twin coaxial cables for each channel, enclosing them in copper wire braid, connect the shielding to Earth.
Use the solid three for signal, and the shield for ground.
If weight was not an issue, use twin coaxial cables for each channel, enclosing them in copper wire braid, connect the shielding to Earth.
I see no reason why the wire has to enter the fulcrum of the arm. It's a naked design and it's made by you, not a commercial TT that has to be idiot-proof and wire-pulling by children...
The conductors from inside HDMI cables are another option. Some are like 32 gauge.
When I was playing with a long arm table, I used a boron fishing rod blank. It was lighter than CF. I wanted to put a 10X gain cell in the head-shell, but was not able to fabricate what I had envisioned. So, base of the arm was as good as it got. In that case, just putting the RIAA amp there ( Old Hafler ) worked as well as it could. About that time CDs got better and I dumped the entire mess. In truth, it did not really track any better than the Grace arm I had, which was marginal over the original Thornes arm. A lot of "magic" with turn tables. Not as much sound as we always hoped. The one really clear tweak was putting the entire thing is a box with a good air seal pretty much eliminating any acoustic feedback. Correct cartridge loading I do not consider a tweak, just correct install.
When I was playing with a long arm table, I used a boron fishing rod blank. It was lighter than CF. I wanted to put a 10X gain cell in the head-shell, but was not able to fabricate what I had envisioned. So, base of the arm was as good as it got. In that case, just putting the RIAA amp there ( Old Hafler ) worked as well as it could. About that time CDs got better and I dumped the entire mess. In truth, it did not really track any better than the Grace arm I had, which was marginal over the original Thornes arm. A lot of "magic" with turn tables. Not as much sound as we always hoped. The one really clear tweak was putting the entire thing is a box with a good air seal pretty much eliminating any acoustic feedback. Correct cartridge loading I do not consider a tweak, just correct install.
I haven't abandoned you guys. Lots of good info here.
I'm looking for a product link to a braided cable I saw, said to reject EMI and RFI, I want to find and post it and ask whether I should make a similar tonearm lead.
I just can't find the link yet. I will.
I'm looking for a product link to a braided cable I saw, said to reject EMI and RFI, I want to find and post it and ask whether I should make a similar tonearm lead.
I just can't find the link yet. I will.
Not braided. A twisted pair. The cartridge provides a balanced output by definition, so a nice 30 gauge pair will be fine. That was the problem with traditional tables, they ran the signal single ended, one side ground. Much more susceptible to RFI. If I were to build phono preamp, it would be a diff input.
If you insist, the "star quad" configuration is said to be good but requires a big core. If you really insist, the old Boy Scouts 4 string braid may be what you are thinking about. May look super cool, but a simple twisted pair works fine. One advantage of the old school aluminum tube arms was it could be grounded providing a shield.
If you insist, the "star quad" configuration is said to be good but requires a big core. If you really insist, the old Boy Scouts 4 string braid may be what you are thinking about. May look super cool, but a simple twisted pair works fine. One advantage of the old school aluminum tube arms was it could be grounded providing a shield.
I have used some tiny Mogami 4 conductor + shield for this. It's meant for HHD heads, I think. Have a look thru the Mogami catalog.
As I mentioned, twisted pairs weren't so great at noise rejection. Not terrible but the shielded wins for sure.
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Also fwiw, some people are mentioning the balanced nature of the phono cartridge output. Unless you have a balanced input on your phono pre, and are willing to separate the chassis ground on the cartridge, well, it isn't running balanced.
That may be the stuff I'm already using. I'm using 2/32 but it is sold with more conductors.
It is pretty fine stuff. The more i think about the Daburn cable, which is #40, the more I think #32 may be the limit for my tired old eyes anyway.
I built my own, using a 0.05mm dia core and 5 0.03mmdia magnet wire as shield. to wind the coaxial i started withthe core hanging down with an allicator as weight. then cut a ribcarton circle about 4", and 5 even cuts on the rim. the 5 0.03 wires were strung from the same point where the core was hangung and attached to the slits. the carbon circle was hanging flat this way. then simply blowing to the side the circle starts turning and the 0.03 wires were wound around the core. careful soldering this thin wire as it dissolves in solder quickly. its a few microns per second.. there exists copper saturated solder to minimize the problem, but it never goes really away....
I once visited the Mogami factory, about 40 years ago when it was a boutique brand. Met the founders the Hirabayashi brothers, one did sales the other was the brains, using early computers to analyze capacitance etc. They showed me an ultraflex 48 pair audio core, intended for the Sarajevo winter olympics. most of their ultra flex business was wiring for HDD heads.
I built various tone arms, one pure pritchard copy, and one pritchard style with solid head. these were built from honduras mahagony, sawn from an old spanish guitar neck. also have used juniper as arm material. honduras mahagony is the best having low weight and an intertwined fiber structure. that is what it is the preferred material for the vintage fender and gibson guitars. until it was forbidden to harvest..
This is the stuff with the braid that is said to maximize rejection (below).
I wonder how well it works, and how easily I could duplicate it with tiny, tiny wires.
https://www.magnetic-shield.com/inter-8-weave-cable/
![INTER-8-ALL__98364.1596427194[1].jpg](https://www.diyaudio.com/community/attachments/inter-8-all__98364-1596427194-1-jpg.1017682/ "INTER-8-ALL__98364.1596427194[1].jpg")
I wonder how well it works, and how easily I could duplicate it with tiny, tiny wires.
https://www.magnetic-shield.com/inter-8-weave-cable/