Why are cables attached to turntables?

[Hi Ho]

This is something I have always wondered. Why are the RCA cables almost always either soldered or connected to RCA jacks on the inside of the unit? Why not have simple RCA jacks on the outside like CD players have?

 

[mike c]

wild guess:

maybe the constant/regular motion of the TT is enough to loosen connections if not soldered (in a given period of time)

 

[fmw]

Because it is cheaper. Once you get past the entry level, turntables have RCA jacks like you would expect.

 

[3db]

Because it is cheaper. Once you get past the entry level, turntables have RCA jacks like you would expect.

Agreed. My ProJect XpressionII comes with removable cables.

 

[TLS Guy]

Because it is cheaper. Once you get past the entry level, turntables have RCA jacks like you would expect.

Actually it has to do with cable capacitance.

Unfortunately every cartridge has an optimal load capacitance. There is quite a range between 25 and 100pf. The scatter has a mean around 50 pf. Most good manufacturers try and get the capacitance of their cables to 25 to 50pf.

However, getting the load capacitance correct for a given cartridge is one of the best improvements you can make to LP sound. An awful lot of the difference in the sound of cartridges is due to this issue alone.

Most good cartridge manufacturers specify the optimal load capacitance. Unfortunately not many turntable manufacturers specify the capacitance of their turntables, nor do many preamp or receiver manufacturers specify the input capacitance of their units.

Fortunately for me SME specify the capacitance of their pickup arm interconnects precisely. They also come with big enough RCA plugs to solder small caps inside the plugs to get the loading correct. They all come with a small cap anyway. Quad specify the input capacitance, so by putting in the correct cap, you get it exactly right. My Quad 44 has a row of little dip switches in the top of the case, that allows you to precisely set the input capacitance of the phone stage to get it just right.

If this matter is left to chance, I can guarantee that the playback curve of your turntable will not be flat.

 

[WmAx]

Some high end arms have the cables attached. My table uses a Clearaudio Satisfy arm has the cable attached, actually, it is continuous. This is a $1200 arm by itself. The wire from the head to rca plug is one continuous piece with no solder joints or other junctions, except for the one at the head leads. The manufacturer felt it was better to have a continuous uninterrupted piece of 'high end' wire. They also offer a RCA plug at the base of the arm version for those that prefer to use their own cables, but my table came with the continuous cable version. Unscrewing the RCA shell on the end, it is incredibly fine wire, as it would have to be if used as one continuous piece through the arm. It does worry me a bit in regards to durability of the cable, using such fragile wire.

-Chris

 

[3db]

Wow!! The things one learns here .