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Upgrading Turntable RCA cables?

Low capacitance, Low capacitance, Low capacitance... (it bears repeating!)

Capacitance is of course a load that increase per length of cable.

Very low C cable (eg: BlueJeans LC1) can be as low as 12pf/ft

My own 1.5m LC1 interconnects measure 54pf

A set of cheap video interconnects 1m long measures 97pf

A high quality audiophile interconnect 1m measures 307pf

Your goal should be to achieve 100pf total capacitance for tonearm and interconnect or less.

Keep in mind that most Audio Technica MM cartridges are designed for a C load of between 100pf and 200pf ... and that most phono stages have some onboard capacitance as well.

Increasing the capacitance to properly match the cartridge you are using is dead easy - use an extender cord, or fit an RCA Y-adapter and use loading plugs. - it is also easily adjustable. (AT's like 150pf, Shure's like 250pf, Ortofon's like 400pf)

You cannot decrease capacitance without replacing cables and doing soldering - so lower is better!!

I replaced my JVC TT's cables with low c cables, and kept them super short (the phono stage sits right behind the TT) - end result is 60pf total capacitance. :thmbsp:

bye for now

David
 
+1 for component video cables. Good quality, better specs and lower capacitance than standard RCA audio as a rule.

I get a set of six footers which gives me enough for three tables. Cut them in half, and mix 'n match the ends provides a usable color code for the plugs. They ARE quite a bit larger diameter than the originals, so you do need to hack 'n slash some, and lots of different ways to do it. The Technics I just did has a metal plate for routing the cables thru the case - I dremeled a slot to slip the cables through, then made a new strain relief grommet with black tape, wrapping it thicker either side of where the cables pass thru the plate.

Acid test for me is whether they'll handle CD4. Which they do with minor recalibration. :thmbsp:
 
If you are going to the trouble of changing your TT leads you should measure any
cable prior to installation for its Capacitance.


Low capacitance, Low capacitance, Low capacitance... (it bears repeating!)
Click to expand...
 
Unless it is a rare collector’s item I would not worry about diminishing the value of your TT by installing good cables. It probably will improve the sound and that what you are after. You can always keep the old cables and offer them to the next guy if you’re concerned.

Go to the Search Tab at the top of the page. Choose Advanced Search at the bottom to the drop down menu.
Use keyword – Interconnects. Leave the default to Search Tittles Only in this case.
In the Search in Forums field choose the Turntable Forum.
In the bottom left in the Show Results As leave it as default Threads in this case.
Lots of good threads will show up.
BTW – You will see PETRA cables mentioned quite a bit. They were the cable of choice for quite a while but unfortunately they are no longer made and the vendors have been out of stock for a long time.
This thread by member hakaplan has a lot of useful information and is worth reading even though it is about the PETRA cables. http://www.audiokarma.org/forums/sho...=interconnects
Here is a more current thread by hakaplan. http://www.audiokarma.org/forums/sho...d.php?t=158411
They also give instructions on how to test for capacitance.
 
I'd like change both of my TTs by getting rid of the cheap RCA cables and either replace them with something of better quality or have RCA jacks terminated at the TT so I would then have to plug RCA cables to the TTs.

I understand my Miracord cables, but my JVC QL-Y7, just seems like a nice TT and they use cheap RCA cables.
 
Very very carefully - your hand holding the probes can alter the capacitance...
Also shifting how close the measuring probe cables are to each other can alter capacitance too....

Best way is to fit alligator clips you can attach to the cable to be measured...

Measure the cable - then keeping all the cables in exactly the same position, disconnect, and measure again - this will measure the capacitance of the probes, alligator clips etc... deduct one from the other and you have your capacitance. (or at least a reasonable estimate thereof!)

To measure the tonearm/interconnect, remove the cartridge (or headshell) and measure the capacitance of the RCA output for each channel (with it disconnected from the phono stage obviously) - they may be slightly different... If they are very different you have a problem!

bye for now

David
 
I'm afraid you'll have to a bit more basic. :sigh:

Say I have an RCA IC, disconnected at both ends from the TT and the phono input... am I connecting the probes to the center pin at each end of a cable, or from center pin to ground ring, or what? :scratch2:
 
Yep - one probe on the center signal pin, and the other probe on the outer signal-ground ring of the rca plug...

that's it! - No need to connect to both ends of the cable, reading at one end is applicable to the entire cable...
 
I'm going to throw a curve into this discussion of capacitance. You preamp circuit likely has added capacitance in it. Most do. It is there because cartridge makers design there products knowing that there is capacitance in the path between the pickup and the preamp so the cartridge is built to expect some capacitance in the circuit. The right amount will get the cartridge sounding as well as it can. Too little however can be just as bad as too much. It is often possible to find out from the cartridge maker how much capacitance the cartridge needs to sound good. Typically, it is a range, with some cartridges having broader range then others. Your setup will sound best when you get as close to the optimum as is practical. Your total capacitance will be what is in the tonearm, the interconnects and the added amount tin the preamp. That third amount is generally the largest and since it is soldered onto a circuit board in your amp the hardest to do anything about.

Since your cables are short and you want to lengthen them, it does make sense to use cables with somewhat less capacitance per foot, so that the increase in length does not cause an overall increase. To do the thing up at its absolute best however you need to know what your cartridge expects and what is in your amp already.

Shelly_D
 
Quite right, which is why it is best to have a phono stage with as little onboard C as possible, adding capacitance is easy - a longer cable, a higher capacitance cable, or a capacitor in an RCA plug on a Y adapter.... it all works.

But if your phono stage capacitance is already above the recommended total capacitance for your cartridge.... then you are proverbially stuffed.

To use a simple example - most of the budget phono stages have 220pf onboard.... most of the Audio Technica Cartridges are optimally loaded with 150pf.... !?!? easy to see why lots of people are reporting their AT440's sounding too bright! :scratch2:

Increased capacitance rolls off the high end more - in actual fact it brings the rolloff point in to a lower frequency - depending on the resistive load used (standard is 47k) this then results in a slight electrical resonant boost at the turnover...
So although you have lost more of your top end, you are also getting a boost in the much more audible lower top end.

So, paradoxically, an AT440MLa with reduced high end, sounds brighter, and harsher.....

The latest budget phono stage from ART has switchable 100/200pf capacitance.... a step in the right direction!

If you can get your arm/turntable IC down to 100pf or below, then a phono stage with 100pf onboard can get you to 200pf total - and the range for the AT cartridges is 100 to 200 pf - so you are then on the margins of the acceptable range... (a switchable 50/100/200 would be better...)

bye for now

David
 
dlaloum said:
Low capacitance, Low capacitance, Low capacitance... (it bears repeating!)

Capacitance is of course a load that increase per length of cable.

Very low C cable (eg: BlueJeans LC1) can be as low as 12pf/ft

My own 1.5m LC1 interconnects measure 54pf

A set of cheap video interconnects 1m long measures 97pf

A high quality audiophile interconnect 1m measures 307pf

Your goal should be to achieve 100pf total capacitance for tonearm and interconnect or less.

Keep in mind that most Audio Technica MM cartridges are designed for a C load of between 100pf and 200pf ... and that most phono stages have some onboard capacitance as well.

Increasing the capacitance to properly match the cartridge you are using is dead easy - use an extender cord, or fit an RCA Y-adapter and use loading plugs. - it is also easily adjustable. (AT's like 150pf, Shure's like 250pf, Ortofon's like 400pf)

You cannot decrease capacitance without replacing cables and doing soldering - so lower is better!!

I replaced my JVC TT's cables with low c cables, and kept them super short (the phono stage sits right behind the TT) - end result is 60pf total capacitance. :thmbsp:

bye for now

David
Click to expand...
And you won't necessarily hear any difference. You're getting into murky territory here, David, much of which remains unproven so should not be stated as fact.

That said, low capacitance in any HiFi cable is a good thing - unless the manufacturer seriously wants to affect the sound - as are short cables.
 
I've replaced my turntables original cables because they seem ugly to me, it was too thicker and rigid, but after replaceing with thiner ones, strangely apear a hum. It's important the quality of shielding of the cable.
 
dlaloum said:
Yep - one probe on the center signal pin, and the other probe on the outer signal-ground ring of the rca plug...

that's it! - No need to connect to both ends of the cable, reading at one end is applicable to the entire cable...
Click to expand...

Got it! That's how I've been doing it but was never 100% sure it was accurate that way. I didn't realize there was a need to subtract the C of the test leads though. That would explain why the readings are different sometimes.

Thanks. :yes:
 
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