Input requested

Sean writes: "If the MI-2's are linear in power transfer, primarily due to very low inductance, and maintain a consistent series resistance to beyond 100 KHz, which is better than ANY other cable on the market, how could it be detrimental to the treble response that you are encountering?"

Because the measurements you cite come from a purely resistive load; when one considers the complex load of the speaker in series with the cables (which is exactly what the amp sees in an actual application), one can use their understanding of how such circuits work and form working hypothesis.

Sean writes: "In effect, the higher inductance of the speaker cable introduces high frequency roll-off. This will in turn introduce poorer transient response, increased phase shifts, smearing and distortions within the audible upper treble region."

Once again, I agree with a purely resistive load! (btw, it is exactly this argument and supporting data you put forward which led to my purchase) But it is nothing more than introductory electronics to understand that capacitance across a complex load will shunt the higher frequency components through it - especially if the series load is inductive (which a speaker is). So, again, the working hypothesis remains....

Of course, your hypothesis would be: within the audible frequency range, there is no attenuation of the signal into the *complex* load. Therefore, what I am hearing is *greater* control of the tweeter which is giving my ears what the signal actualy is (thus, the "air" that I hear is nothing more than sloppy control of the driver).

Now we're exploring which hypothesis explains observed and which is the better explaination is now open to objective inquiry. If you, or anyone else in the forum, have done such measurements, then that would prove invaluable in my understanding of this confusing topic.

As an aside, I am hardly trying to provoke or challenge you, Sean. There are enough flamefests which take place without a relative newbee adding to fray. Instead, I'm trying to understand and have framed the discussion in the most constructive way I know how.

Best,

Lee

a.k.a.

Mprime: i did not take your response as being "hostile" or "challenging" and i hope that you didn't perceive mine in that fashion either. I was simply trying to ask questions to get you thinking about the big picture and provide a point of reference via the links and explanations given.

As far as your comments go about the electrical characteristics of the cable combining with the electrical characteristics of the speaker to form an even more complex load to the amp, i agree. I have stated many times that cables act as an impedance transformer between mating components.

Having said that, the factors involved here are massively variable from combo to combo due to the lengths of cables / actual speakers used. As such, it would be hard to come up with "generic" equations that are representative of all possible combinations in terms of potential high frequency inter-action levels.

On top of that, given the typical length of speaker cable involved in most "audiophile" type installations ( relatively short ), the amount of capacitance involved with the flat Goertz isn't cumulative enough to really play havoc in the manner that you suggest. Now if one were to use a very long quantity of their MI-3's ( their heaviest gauge / highest capacitance model ), i could see some potential problems possibly arising from this. The "but" here is that much of how influential this was on the system would have to do with what type of load the loudspeaker itself produced at or slightly above the audible treble region.

As a side note, are you leaving your Forte' powered up 24/7 or turning on as needed? These amps sound SO much better after being powered up continuously that it's not funny. My findings are that 48 - 72 hours after initial turn-on, what you hear is what you get. Obviously, the main concern here is heat dissipation and power consumption. Given that this is a Class A amp, it will run quite warm and dissipate a lot of heat. As such, it's not a good amp to have encased in an enclosed rack or even an open rack with a shelf directly above it. If your rack is open to the sides and you can provide appr 6" - 8" of open space above the amp, you should be okay. Even at that distance, the shelf right above the amp will still get noticeably warm.

Based on my personal experience with these cables i had never gotten the "liquid" midrange response or "soft, delicate & airy" highs from any cabling that i had tried until i switched over to the flat Goertz cabling several years ago. Until that time, treble response was always "splashier" with less definition, more smearing and suffered from reduced harmonic structure. I had attributed much of this to reduced skin effect ( even Audioholics comments that Goertz cabling are one of the few that can actually make this claim ), a lower nominal impedance resulting in improved loading conditions and the fact that there is one consistent length signal path for the entire frequency range to travel ( solid vs stranded ). Either way, my results with using this same exact cable cable and same brand of amp is VERY different than what you are describing.

To add further confusion to the issue, i've been "upgrading" my Father's system over the last few years for him. After replacing his tubed preamp with an SS preamp of another brand ( FAR superior sonics in every aspect ), replacing his two channel amp with a five channel model of another brand ( FAR superior bass control and smoother treble ), installing a hand built DAC using audiophile grade parts ( FAR superior sonics in every respect, especially liquidity and spatial characteristics ), trying over a half dozen different digital cables, etc... my Father was the most enthused with his system after we replaced his Audioquest speaker cabling with Goertz MI-2's. His own words were "I think that those cables made a bigger difference than all of the other changes combined". While i don't agree with that, i told him "the Goertz cables finally let all of the cumulative upgrades further up in the signal chain shine through". In effect, it was kind of like adding icing to what was a potentially very tasty cake.

Even though all of the components were the same, the difference in "musicality", presentation and "texture" were extremely and vividly different when the AQ and Goertz cables were in the system. I ended up taking this a step further after we gutted and modified his speakers, which took things another step forward. I'm now working on his AC system, which should provide further gains in terms of increased liquidity, reduced grain and glare, improved dynamics and an overall lower noise floor.

There is one factor here that i've not really thought about. That is, the Zobel networks. I've never used the factory supplied Zobel's. I've always built my own using higher grade parts. While i don't know how much this would alter what you are hearing ( it really shouldn't ), i know that Jon Risch at AA is pretty adamant about using the best parts possible for a Zobel. While i would not recommend removing the Zobel's from your cables with this specific amp, you might want to think about replacing the existing Zobel's with some hand-built pieces. I don't know whether or not this will solve your problems or take you a step forward, but other than looking elsewhere in your system for potential solutions, that's about all i can suggest. The bottom line though is that you have to run what you like and think works best. Nobody will ever fault you for that. Sean
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