Inexpensive Low Capacitance Phono Cable?

[vortalexfan]

Hello Everyone, I just recently picked up a Technics Vertical Linear Track Turntable Model SL-V5 That I was told in the original thread I had posted for said turntable that I was going to need Low Capacitance Phono Cable for it.

Which I didn't believe the person at first until I went to hook a regular set of RCA Audio Cables up to the turntable and to the receiver of mine and noticed that when I played a record there was a hum coming through only when tone arm was set down on the record and it didn't hum any other time and after doing some research online I found out that the guy was right.

Apparently Moving Magnet type Cartridges need lower capacitance type RCA hookup cable because otherwise it will hum and pickup lots of other electromagnetic interference/noise from nearby electronics.

During my research in trying to find some decent low capacitance interconnect cable for my turntable I found that most of the low capacitance cabling was between $50 and $300 and that's way out of my price range of what I'm willing to pay or can pay for a good set of low capacitance phono cable.

Is there a source for good quality low capacitance RCA Phono Cable that is under $50? If there is, I would like to know where that is so I can order some
for my Technics SL-V5 turntable so I can get it up and running with my stereo.

Any help and suggestions would be appreciated.

Thanks.

[Electronic M]

If you have a decent sized component stereo system and a lot of RCA cables from different sources you may already have one. Quadradisc/ CD4 records require audio cable with less than 100 pF to work so when I got a few records and a decoder I took a capacitance meter (at the time all I had was my Heathkit C3 and a 100pF reference cap) and a bunch of cables I had and started testing. Shorter cables will have less capacitance and capacitance increases with length. I found I had 2 good candidates a short cable (about 2') that was just long enough to comfortably place my decoder/preamp next to the turntable, and a longer cable that had low capacitance per-foot that I'd need to cut down a bit to meet capacitance spec but could get more length out of than the short cable... ultimately I went lazy and used the short one.

IIRC most coax available from parts supply houses should have capacitance per foot in the datasheet and possibly search filters...if you don't mind adding your own RCA Jack's that should be another cheap route.

[old_tv_nut]

Not sure why low capacitance would have anything to do with hum. Could be important for high frequency response.

I haven't shopped for turntable cables in decades, and looking around now, I think the prices being charged without giving this one most-important spec are criminal.

[old_tv_nut]

I think I would try these for $8.99 in 4-foot length:
https://smile.amazon.com/dp/B01D5H8P..._t1_B01A7SG6WK
Caution - see the review comment about the diameter of the connectors making them not useful if the equipment jacks are too closely spaced

The large diameter of the cable may be an indication of low capacitance.

If your turntable and amp have ground lugs, add a simple ground wire, type is not critical.

[vortalexfan]

Well the hum I'm hearing on my turntable only appears when the tonearm is engaged (its a Linear Track Turntable) and its not the hum you hear when the ground wire isn't connected its a different frequency of hum altogether (its not a 60 hz hum like you would get with a disconnected ground, it sounds more like a 120 hz hum or something like that.)

And from what I was reading online on sites like Audio Karma (The Sister Site to Video Karma) and the Hoffman audio Forum, that record players with MM cartridges will hum if the right low capacitance wire isn't used.

I do have a shorter 4 foot audio cable that says "Japan" on it, that was probably originally from a turntable, but its too short for the span I need, I need at least 6 Feet of cable to go between the back of the turntable and the back of my receiver, the span between the two is about 6 feet.

Would Wal-Mart have anything?

[old_tv_nut]

I think the "correct low capacitance cable" is mixing up two things: low capacitance and good shielding. You need both.

I don't know how the linear tracking mechanism works. Could there be a small motor that drives it that comes on and produces the hum? At this point, I would take the question over to AudioKarma.

[vortalexfan]

Originally Posted by old_tv_nut

I think the "correct low capacitance cable" is mixing up two things: low capacitance and good shielding. You need both.

I don't know how the linear tracking mechanism works. Could there be a small motor that drives it that comes on and produces the hum? At this point, I would take the question over to AudioKarma.

And Unfortunately I know very little about the Linear Track Record players except that they work similar to how a CD Player works, and from what little information I could find about linear track record players on the internet through other forums is that most of them use p-mount type cartridges which are usually of the MM type and those generally require low capacitance connecting cables from what I read (and what one of the members on here said).
I don't think its the motor for driving the tonearm that's introducing the hum because its very well shielded to prevent such interference with the audio.

I definitely think its an audio cable issue or something along those lines because from what little research I can find online about the SL-V5 turntable it definitely needs special audio cable, but as to where to source it at cheaply without having to spend a C-Note for it is what I'm trying to figure out.

[Ed in Tx]

Is it the original cartridge?

MM cartridges need a certain amount of capacitance for a flat freq response. The maker will typically spec the loading at 47K Ohms and some capacitance between 200-400 pF. The low capacitance cables like mentioned before really came into play in the '70s with the old CD-4 records with frequencies up to 50 kHz that needed 100 pF and 100K Ohms load to work right. With that CD-4 loading a typical stereo cartridge would usually sound bright.

Some turntables have a mute switch that operates while the arm is moving and landing on the record so you don't hear that initial noise of the stylus finding the groove (or lifting at the end). That could explain why you don't hear the hum until the record starts playing.

I assume there are no components with big transformers, or fluorescent lights nearby that could be inducing hum. And you have the separate ground wire and it's connected.

[vortalexfan]

Originally Posted by Ed in Tx

Is it the original cartridge?

MM cartridges need a certain amount of capacitance for a flat freq response. The maker will typically spec the loading at 47K Ohms and some capacitance between 200-400 pF. The low capacitance cables like mentioned before really came into play in the '70s with the old CD-4 records with frequencies up to 50 kHz that needed 100 pF and 100K Ohms load to work right. With that CD-4 loading a typical stereo cartridge would usually sound bright.

Some turntables have a mute switch that operates while the arm is moving and landing on the record so you don't hear that initial noise of the stylus finding the groove (or lifting at the end). That could explain why you don't hear the hum until the record starts playing.

I assume there are no components with big transformers, or fluorescent lights nearby that could be inducing hum. And you have the separate ground wire and it's connected.

Hi, I have the original Owners manual and Service manual for this record player that I downloaded from Vinyl Engine shows that the original phono cable that came with this turntable was a 150 pF capacitance cable.

As for the cartridge that's currently on this turntable is a Shure M92 LT cartridge and the owners manual for this turntable says specifically that this turntable can use whatever P-Mount cartridge you wanted with it as long as it was rated to be used with a linear track turntable.

And as for whether or not there's any florescent lighting or equipment with large transformers nearby, that would be a big no.
Unless you count the power transformer in my Pioneer SX 1000 TD Stereo receiver.

Which if that's the case then, whats the point of using a record player that's going to be susceptible to the power transformer in your receiver?
Because last I checked most stereo receivers of good merit (50 WPC+) have pretty decent sized power transformers in them.

And yes I do have the ground wire connected and as I stated before, its not because of the ground wire, because the hum is the wrong frequency and also the record player doesn't hum any other time except for when the record is playing, and the "no ground wire connected" hum would happen regardless of whether or not the record was playing or not.

[Ed in Tx]

Originally Posted by vortalexfan

I downloaded from Vinyl Engine shows that the original phono cable that came with this turntable was a 150 pF capacitance cable.

That, added to the inherent capacitance of the tone arm wiring and input to the receiver probably adds up to 300-400 pF, acceptable for the Shure. Good quality audio cables kept to a minimum length should work fine.

Originally Posted by vortalexfan

And as for whether or not there's any florescent lighting or equipment with large transformers nearby, that would be a big no.
Unless you count the power transformer in my Pioneer SX 1000 TD Stereo receiver.

Would have to be within inches.

[vortalexfan]

Originally Posted by Ed in Tx

That, added to the inherent capacitance of the tone arm wiring and input to the receiver probably adds up to 300-400 pF, acceptable for the Shure. Good quality audio cables kept to a minimum length should work fine.






Would have to be within inches.

Well actually the turntable is sitting right next to the stereo receiver about 6" over from it on top of a stack of cassette tape storage drawers that are sitting on top of a speaker which was the only spot I could sit the turntable as the turntable is too tall to sit on my hutch with the rest of my stereo equipment (shelves are too short).

As for the cable length, it has to be longer than 4 feet otherwise the cable won't reach between the back of the turntable and the back of the receiver, I tried it already.

[old_tv_nut]

Just for grins and giggles, have you tried disconnecting the ground wire to see if things get better or worse?

Another thought: are your receiver and turntable plugged into the same outlet?

[vortalexfan]

Originally Posted by old_tv_nut

Just for grins and giggles, have you tried disconnecting the ground wire to see if things get better or worse?

Another thought: are your receiver and turntable plugged into the same outlet?

Actually when I disconnect the ground the hum did go away oddly enough but then when I touched the ground wire plug that goes into the turntable it would hum again.

As for what the turntable is plugged into, it's plugged into the switched outlet on the back of my receiver.

[old_tv_nut]

Originally Posted by vortalexfan

...when I touched the ground wire plug that goes into the turntable it would hum again.

Not following what you mean by "the ground wire plug that goes into the turntable." Do you mean the place where the ground wire connects?

[old_tv_nut]

Also, if the power plug for the turntable is not polarized, have you tried turning it around?