Are phono cables really diferent from other cables?

[Blumlein 88]

Here is another case where flexibility is a necessity in tone arms. Those that use linear tracking. Especially the tiny cable that goes to the cartridge, but even the one that feeds into the RCA's needs to be flexible. Here is an example in the ClearAudio Souther Triquartz arm. If it is not clear the three wheels position the cartridge holder on a rail and roll back and forth across the LP. It has to be very light and you don't want to restrict the cartridge and you don't want vibration getting into the whole rig via the RCA cable. Pretty terrific linear arm when you get it all set up correctly.

 

[Nutul]

Are ADAT fiber optic cables shielded or not shielded? Confused.......

You are kidding, right? ...right...?

 

[Sal1950]

No, it's fixed to the bottom of the horizontal pivot.

So then there's tiny tonearm wiring that is submitted to the tonearms lateral and vertical movement and
nothing (very little) to cause any loading of the bearings? They end up terminated at the bottom of the tonearm
where the cable plugs in. Basiclly the same as below, or am I misreading you?

"Some TTs (e.g., the old AR) have the tonearm wires go to a terminal block mounted on the plinth"

 

[Sal1950]

You are kidding, right? ...right...?

 

[morphemes]

When it's coming out of a cartridge it's more like a pair of balanced microphone cable than what we'd think of as RCA, but the standard has always been phono, RCA invented RCA for phonographs... Ground isn't common to the negatives yet direct from the groove.
Coax for unbalanced, STP for balanced.
Coax for RCA, STP for phono..
Coax would do fine but the conductors really should match because the cartridge is like a dual dipole Bloom line kind of thing it's supposed to match, coaxial breaks the L-R L+R coincidence all 4 directions should be going down matching conductors before they're pre amplified. Modern RCA all one sided and amped up.

 

[rcstevensonaz]

When it's coming out of a cartridge it's more like a pair of balanced microphone cable than what we'd think of as RCA, but the standard has always been phono, RCA invented RCA for phonographs... Ground isn't common to the negatives yet direct from the groove.
Coax for unbalanced, STP for balanced.
Coax for RCA, STP for phono..
Coax would do fine but the conductors really should match because the cartridge is like a dual dipole Bloom line kind of thing it's supposed to match, coaxial breaks the L-R L+R coincidence all 4 directions should be going down matching conductors before they're pre amplified. Modern RCA all one sided and amped up.

This is an interesting point and helps me (finally) understand why people keep saying phono is a "balanced" source from the tonearm. But, I think you leave too much of the parallelism in your construct "for the reader to understand".

Where the point is that both connectors coming from the turntable's arm to the RCA's tip and sleeve are impendence matched (i.e., balanced), not that the receiver preamp is implementing a balanced differential driver (e.g., for CMRR). [Edit: my original statement about "impendence matched" is wrong, and also spelled incorrectly. See comment #87 from @Speedskater below for the correction.]

Would the following an accurate rewording of your point using a few more words to ensure my brain understands your point?

• In general: Coax wire for unbalanced interconnects, STP wire for balanced (i.e., impedance matched) interconnects
• In specific: Coax wire for RCA interconnect between unbalanced line-level audio devices, STP wire for a balanced RCA interconnects from turntable

But, wasn't the original phono RCA specification based on using coax cables, which is not an impedance matched wire? In which case, aren't all turntable preamps also designed assuming a coax (unbalanced) connection instead of a 2-wire STP (balanced) connection?

 

[Speedskater]

That's a different meaning for "impedance matched".
Not the common: "Radio Frequency Characteristic Impedance"
But 'symmetrical about ground'. That is, each central wire has the same resistance and the same capacitance to the shield.

 

[rcstevensonaz]

That's a different meaning for "impedance matched".
Not the common: "Radio Frequency Characteristic Impedance"
But 'symmetrical about ground'. That is, each central wire has the same resistance and the same capacitance to the shield.

Thanks for that clarification. I've updated my original comment accordingly.