Audioengr: Glad to see that we are on the same page i.e. my previous comments about deficient design of the gear ( specifically the power supply ) making them more responsive to power cord changes. If you want to take your designs / upgrades to a new level, try installing a Zobel network into the power supply. This will attenuate the ringing that the transformer itself generates. This will make each unit more universally consistent in performance, which in turn would also deal with Flex's question that he posed to you. If using such an approach, you'll find that proper AC polarity is critical.
Corona: While you've never been one to give away any of your design concepts, i'd really love to pick your brain / compare notes. Too bad doing so will cost me hundreds of dollars i.e. having to buy one of your products and reverse engineer it : )
Slappy: I think that people look at AC cords in the wrong manner, much as i used to a few years back. Rather than thinking of them as an extension of the wall outlet, think of them as an extension of the unit's power supply. Since one can design different aspects of filtering and / or reduce the susceptability to picking up / re-radiating noise on the line or noise generated within the equipment itself, what stops one from doing the same with a power cord ? After all, filters are comprised of inductance, capacitance and resistance and all of these electrical characteristics can easily be manipulated in a power cord.
Once you understand this concept, you'll realize that it does not matter how far or long the AC has to travel to get to your outlet or how dirty that AC is. What does matter is what a filter is trying to accomplish, how effective that filter is in achieving those goals, where it is placed within the circuit and if there are any noticeable drawbacks to such an approach.
As far as most commercial designs / designers go, they only look at a very small portion of what an AC cord should and shouldn't do. As such, they typically only look at the "good things" that they want to see and forget about what the side effects are to the approach that they used to achieve those goals.
A perfect example of this is "shielding" While shielding is beneficial in ALL cases, the way that most designers impliment shielding is typically loaded with drawbacks. This creates other problems all their own. Having said that, the drawbacks of poorly implimented shielding may not be as noticeable with some specific types of equipment as it is with others. Sharp audiophiles with resolving systems have noticed this using nothing more than their ears, but test equipment can / will / does verify what and why they were able to discern the suitability of some cords over others with specific pieces of gear. Obviously, there are different methods and materials used for shielding purposes, so take these comments with a grain of salt and an open mind.
JD: I don't remember what specific thread it was in, but it might have had something to do with a Philips SACD 1000. That was the player that i did the testing with. I explain how / why i did that specific testing in that thread. As mentioned in that thread, the really "weird" thing was that the only difference between the two cords used / measured was in how the cable was grounded. While the SACD 1000 has NO ground at the IEC jack on its' own chassis, altering the ground on the AC cord itself changed the impedance of the cord enough to effect the units performance into the system as a whole.
As far as amplifiers designed for musical instruments go, most of them are SO poor that changing power cords might / might not make a difference at all. This is especially true of bass guitar equipment, as the speakers / cabinets that they are using are HORRIBLE to say the least. If you doubt this, you should try feeding a frequency sweep into a bass amp & cabinet and see what you get. The open "E" will be so low in output compared to the other strings that you don't experience the impact or extension that an electric bass is capable of.
Suffice it to say that most all commercially available bass and PA cabinets are utter crap. Once again though, cheap and sloppy vented cabinets dominate the market and sound quality / performance has taken a back seat to efficiency / reduced production costs. I could go off on a tangent about this subject alone, but i won't. If you want further info about this, email me directly. Sean
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PS... About 15 - 20 years ago, i used to run a limited edition neck through body Ibanez Musician 944 with active Bartolini's into a Crate preamp electronically crossed into an SAE 2600 ( 600+ wpc ) feeding eight 18's and eight 10's. Yes, i could shake the foundation of the Earth. No, i haven't touched it in a long time as i went into doing sound rather than playing.
