Directionality for Alphacore Goertz MI 2 cable?

Goertz supplies Zobels with EVERY set of speaker cables that they sell or supply to dealers. If you did not get the Zobel network, contact your dealer and raise hell. Unless you know for sure that your amplifier will not react to a high capacitance load, you should ALWAYS use the factory supplied Zobel network. I would not consider the use of the Zobel to be "optional" in 99% of the installations out there. The factory supplied Zobels are designed to stabilize the load that the amp sees starting at appr 160 KHz, so it will not affect the sonics of the system, only the stability of the amp.

As to hearing bright and grainy, that sounds like your amplifier crying out for help. Without the Zobel network and depending on the design of your individual amplifier, you may have what is effectively a dead short to the amplifier at VERY high frequencies. This can result in smearing and distortion of the signal in-band. Take the Goertz out of your system RIGHT NOW before you run into major problems OR install the Zobel networks pronto. If you do not do this, you are looking at blowing the outputs of your amplifier and potentially your speakers.

As to the sonic characteristics that you hear after the Zobel's have been put into the system, you are hearing what your system really sounds like. Goertz cables do not suffer from skin effect, limited bandwidth, high series resistance, etc... As such, it will lay the soul of your system out before you without mercy. At the same time, it will not introduce sonics of its' own because of the aforementioned electrical characteristics. If your system still sounds bright and grainy, time to start looking for other sources of the offensive noise that you can hear.

Out of curiosity, what length of MI-2 are you currently using ?

For the record, it is not a matter of an amp using large quantities of negative feedback that can cause instability to occur with highly capacitive cables. It has to do with how the feedback network is designed and the bandwidth of the amp.

I am using those cables with a Bryston 9B driving 20 v.2 and 60 v.2 and not having any special problems with highlighting/brightness. What amp do you have?

Hi Jvogt,

Actually, it is low negative feedback, broadband amps, like Stasis and Spectral that have issues with Goertz cables. I have heard that Spectrals are so susceptible to this that they will not guarantee their gear unless you use their MIT cables, which are zobeled. Global feedback makes an amp more stable, but that comes at a price, as they do not sound as good. Nelson Pass has something on this at his site, I think it is under the article on cascode amps. The more feedback, the more you kill the highs, which kills air, etc...

Thanks to all for the posts on this thread. I will install the Zobel's this afternoon.

The MI(2)'s I am auditioning are 6 feet. My amp is an Arcam Alpha 8R which is a warm amp and have had no problems to the present with Mapleshade Double Golden Helix or Audioquest Type 4+.

Right on Lou !!! Slow amps with limited bandwidth and poor rise time using gobs of negative feedback have nothing to fear from these cables. Then again, amps of this nature are not typically found in audiophile systems nowadays. This is due to the poor sonic characteristics that they introduce into the system ( lack of air & high frequency detail, veiled midrange, etc.. ). That is the reason why i recommend using the Zobel's for the mass majority of installations. Most SS amps have come a long way since the 1970's in terms of the spec's ( lower grade parts and circuitry with greater error correction ) vs sonics ( faster & wider bandwidth circuitry with better quality of parts ) approach to building and designing SS amps.

Bare in mind that even if an amp can't deliver rull rated power at very high frequencies, that will NOT keep it from "trying" to deliver power at those ultrasonic frequencies. Since the amp is trying so hard to reproduce power at out of band frequencies, the signal that is being reproduced in-band is compromised. As such, the Zobel's may even be beneficial to amps that are not normally thought of as being "fast" or of limited bandwidth design. Sean
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