Phono cable - necessary?

I always thought a phono cable was only necessary if the turntable had a din connector that made use of a regular IC cable impossible so I never really paid much attention to phono cables as my VPI has the typical RCA box for the tonearm. Just recently my dealer told me that phono cables actually use special geometry and construction necessary to conduct the weak signal from the cartridge to the phono preamp properly. I felt flat out embarrassed that I was ignorant of that fact for so long. That said, what is the consensus among audiophiles on this issue? He recommended a Nordost Heimdall 2 phono cable, which at about $650 is certainly not cheap. I am looking to replace my current "phono" cable (Acoustic Zen WOW) as I don't like how thick and rigid it is, even though I really like it sonically. Any advice on the subject?
I had and used the original Heimdahl phono cable.  I could never get the tone right.  It was nowhere near neutral and eventually my wife stopped listening with me as the sound offended her more acute hearing at certain frequencies.  Sold it here and never looked back.  Currently using a Wireworld Atlantis III as a phono cable.  Considering getting a Morrow Audio phono.

Why not use a VPI cable?
Currently using plain old Audioquest RCAs with a generic ground wire on a Classic.  Had previously even went as far as two meters hooked to barrel connectors from a Rega table.  YMMV. 
If you want to listen to the nearest radio station in your speakers you can use any normal interconnect cable, but if you don't want any issues with hum noise and radio stations you need a properly shielded phono cable to transfer singal from phono cartridge to you preamp. The best phono cable i have ever tried is Stereolab Master Refference PHONO RCA. The budged option is Zu Audio Mission Phono RCA mk2 with WBT RCAs. Never use a normal interconnect for turntable!
I've never had any hum or radio bleed-through problems with my turntable. The WOW is actually very well-shielded as are many "regular" IC cables on the market. I'm just curious if there is any theoretical or empirical basis and support for the claim that the signal from the cartridge benefits from a different cable than an IC used between a preamp and an amp. 
Chakster, there are many "normal interconnects" that will provide excellent shielding, and can be used successfully in phono applications. Although of course there are others that do not.  For starters, see this recent thread, especially the responses by Atmasphere and Mofimadness, both of whom have exceptionally extensive vinyl experience.

Marek (Actusreus), what the dealer told you is somewhere in the middle ground between a considerable oversimplification and complete nonsense.  And I would suggest that grains of salt be liberally applied to any future recommendations he may provide.

The most basic criteria for a phono cable are good shielding and low capacitance, as Atmasphere indicated in the other thread.  Although as can be seen in that thread there are some who even prefer cables that don’t meet those basic criteria. 

And good shielding and low capacitance can be obtained very inexpensively, witness humble Blue Jeans LC-1 for example, which is excellent in both respects while being nominally intended for use as a line level interconnect.  The ground wire that is often necessary can be implemented separately using ordinary insulated hookup wire of moderate gauge.

I am not necessarily suggesting Blue Jeans, however.  Beyond those basic criteria, as with most cable selection endeavors it comes down to system synergy, the sonic preferences and budgetary preferences of the listener, and trial and error at a variety of price points.

Best regards,
-- Al
Your words of wisdom are greatly appreciated, as always. I actually saw your recommendation for the Blue Jeans cable in a recent phono cable thread started by Pani, and was going to take a look at it. Just curious, what is considered low capacitance for an IC?
... what is considered low capacitance for an IC?

There are no hard and fast thresholds, of course, and the total capacitance of the cable, which is what matters, is directly proportional to its length.  But as a rough rule of thumb, I would consider 20 pf/foot or less to be low, 20 to 40 pf/foot to be medium, and more than 40 pf/foot or so to be highish. 

Blue Jeans LC-1, as you’ve seen, is about 12 pf/foot.

"pf," by the way, is short for picofarads.  1 pf = one trillionth of a farad, a farad being the basic unit of capacitance, although 1 farad represents an **extremely** large amount of capacitance, at least in the context of electronic devices.

Best regards,
-- Al

Almarg "Chakster, there are many "normal interconnects" that will provide excellent shielding, and can be used successfully in phono applications. Although of course there are others that do not."

Yes, not all of them and i've had that issues. It's also depends on the area where you live. When the unshielded cable catch the radio signal and you hear someboby's voice in your speakers it's a strange feeling. Why not use just a phono cable designed for phono signal? 

The construction of Stereolab Master Reference Phono is quite interesting and the sound is spectacular like everything from Chris Sommovigo who desing the cables for a long time. 

Without the physics or  EE principles of any sort, I went with small diameter silver.  I used Home Grown cable's  Silver Lace (1 M)  for years and generally recommend such cables. I had 2 systems with TTs and used Silver on both, with I thought, great success.

Listen to Al, but if you have some silver cable that would fit, try it you might like it.

I have the Nordost Frey 2 on loan for the weekend so that should at least tell me if a designated tonearm cable makes a difference. Especially, based on the price alone it should!
Is cable capacitance of less consideration when used with a low-impedance MC into low-ish input loads (<1KOhms)?
Is cable capacitance of less consideration when used with a low-impedance MC into low-ish input loads (<1KOhms)?

Yes, it will tend to be less important in that situation than in most others. But it can still be significant because depending on the phono stage reducing the capacitance may allow sound quality to be further improved by increasing the value of the resistive load.  For further explanation see the post by JCarr (Lyra cartridge designer) dated 8-14-2010 11:20am in this thread.

BTW, I should add to my previous comments that there are a few situations in which minimizing cable capacitance will not be optimal.  Those would involve certain moving magnet cartridges that are specified to work best when loaded with high amounts of capacitance, e.g. 400 to 500 pf, especially if the input capacitance of the phono stage (which is often unspecified) is low.

-- Al

Good read.  Thanks, Al.
Look at AntiCable...  top of the line sounds very much like Wireworld top of the line.  They have a money back guarantee.  (not affiliated)