DIY Schroeder Tonearm???

[K.A.B]

When I tried one braid for a DIY arm I made all warned me that there would be some cross-talk, but it turned out that it was not so.

Then I tested the twisted wire to hear the difference but I heard non at all between these two. I have no measuring equipment, but I think the signal is so weak from the cartridge there will be no interference.

I tried to braid them tight and lose do not braid tight the cable will be dull and boring medium to lose is preferable. To tight are to stiff and interupt the movment of the tonearm too.

Anders

Originally Posted by Jeffrey Davison

I don't know if I'd like to braid both channels (L+R) into one braid, or even twist all 4 together. I'd be afraid of potential cross-talk between the channels.

Jeff

[Jeffrey Davison]

Interesting picture..... In this arm, it appears that Frank has intertwined the left and right channels into a single quad braid.......

Frank, care to comment?


Jeff

[K.A.B]

Thats are Cardas braid in the picture I got 1m around 3 ft of it to my clones I braid it like this before.

Anders

[EC8010]

Almost all arms twist all the wires together because it's easy to do and most arm manufacturers are mechanical engineers not electronics engineers. However, twisting the channels individually as pairs works better IF you have a proper balanced input. That means either a balanced transformer or a differential electronic input. Star quad would be even better but I doubt if it's necessary. After all, most people manage adequate results with single-ended inputs; a balanced input with twisted pair is very nearly immune to everything. Star quad is used in TV studios when you need to run long microphone cables next to lighting cables driven by dimmers.

And yes, I take each channel as a twisted pair from cartridge to transformer input. I don't get hum. Not even if I put a finger on one pin of the cartridge at full volume.

[Jeffrey Davison]

On my systems I don't run balanced, but I do run complete S.E. dual mono. Also, I'm running a high GM input tube (6C45S) all tube phone pre, with 3 gain stages, the 6C45S, then an LCR RIAA, then two stages CCA's with no input transformer (70 db gain and no hum).

JD

Originally Posted by EC8010

Almost all arms twist all the wires together because it's easy to do and most arm manufacturers are mechanical engineers not electronics engineers. However, twisting the channels individually as pairs works better IF you have a proper balanced input. That means either a balanced transformer or a differential electronic input. Star quad would be even better but I doubt if it's necessary. After all, most people manage adequate results with single-ended inputs; a balanced input with twisted pair is very nearly immune to everything. Star quad is used in TV studios when you need to run long microphone cables next to lighting cables driven by dimmers.

And yes, I take each channel as a twisted pair from cartridge to transformer input. I don't get hum. Not even if I put a finger on one pin of the cartridge at full volume.

[berlinta]

Hi Jeff,
The braid has two functions. Lowering succeptability to hum and, more importantly, making shure that the wire, once inside the armwand, can't "flop around". The double twisting is a viable option, but with low impedance carts running into a balanced(or even unbalanced) high impedance input, hum will only become an issue if you placed your turntable too close to a hum source, like a mains transformer(not a good idea in any case....).
Plainly twisting 4 wires(most often found) will reduce RFI interference to a degree, but doesn't do much against hum(unless it has A LOT of turns per cm, like Nordost Valhalla).
It will increase crosstalk as well, but all carts a way worse in that department, particularly above ~7kHz, where capacitive coupling comes in.

Cheers,

Frank

[Jeffrey Davison]

Thanks Frank!

Jeff

[binspaul]

Guys,

What is the final conclusion - double twisting or quad twisting ?

Best regards,
Bins.

[Jeffrey Davison]

your choice. imo, there are no "absolutes"

jd

Originally Posted by binspaul

Guys,

What is the final conclusion - double twisting or quad twisting ?

Best regards,
Bins.

[binspaul]

JD,

What is the recent development with your project ? Any new pics ? I will be getting my arm parts this week end. What is the method used to keep the brass & aluminium plates shining/intact ?

Best regards,
Bins.