Not a ground loop hum???

Have you ever verified that your equipment and AC outlets are properly oriented in terms of polarity? Some components are HIGHLY sensitive to AC polarity. Having one component that is not oriented properly connected to others that are oriented properly can introduce a hum into the system.

Out of curiosity, how loud is the hum and at what distance from the speakers is it audible? Is the hum a constant level or does it vary with the gain of the preamp? Have you ever tried connecting the amp to the speakers by itself to see if it hums? If not, try that and see what happens. If no hum, hook up the preamp to the amp and then give that a shot. If nothing, then hook up the CD to the pre and see what happens. If you get a hum with all three hooked up, then try the CD directly into the amp ( NO discs in the unit unless you can vary the output of the CD player ). As usual, it is all just a matter of step by step diagnostics and trouble-shooting. Sean
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Mghcanuck: I just realized that, going by your moniker, you are probably Canadian. If that is the case, i can no longer help you. Sorry 'bout dat.

Bwahahaha. I had to do that just for the sake of Pbb always spouting off about Canada and the superiority of things Canadian. I hope that he and other Canadians can laugh after they get over the initial shock value. What good is "hanging out" if you can't have some fun at one of someone else's expense : )

Getting back to the point, just because a device uses a three prong or polarized two prong power cord doesn't mean it can't be wired with reverse polarity internally. On top of that, one can have correct polarity, but if there is a difference in ground potential from one component to another ( due to leaky cap's, resistive connections, etc...), you can also run into a hum. You'll need to disconnect ALL of your interconnects to check thi AND have access to an inexpensive multimeter too.

When checking components individually, you have to disconnect interconnects between them, not just turn them off. This is both for checking component polarity AND finding out what specific component or combination of components is causing the hum.

As far as the power line conditioner making noise, it may be something as simple as loose nuts & bolts holding down a transformer or a lack of internal damping. I agree that buying a product to solve a problem and then creating another demonstrates a lack of product engineering. Then again, it might be a great product and simply slipped through the cracks of "Quality Assurance".

Having said that, you might want to check into a device that Kevin Deal of Upscale Audio sells. It is supposed to suppress DC offset problems in the AC line, which can cause some of the problems that you are experiencing. From what i've gathered, i think that he sells it with some type of return policy, so find out the specifics before shelling out the cash.

As a side note, a quantity of DC on the AC mains will cause your transformers to run much hotter than normal. Then again, some high bias amps will "warm" the transformer quite noticeably, so this can be a hit or miss trick when dealing with amps. Sean
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Try this thread about Noise, hum and AC polarity. Sean
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PS... I am by NO means a "super-patriot", but your humourous response tells me that you at least weren't offended by my crass sense of humour : )

Swampwalker: Your preamp is poorly designed and lacks stability. Adding the conductivity of your body to the electrical characteristics of the preamp via chassis ground is enough to alter the performance of the circuit in what is an audible manner. If audio components were properly designed, their chassis wouldn't be connected to the active circuitry in any way, shape or form. Sean
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Max: Why don't you call up Blue Circle and let then know what is going on. If you don't have a local dealer that you purchased it from, BC should cover the bill on shipping both ways since this whole mess was due to their lack of quality control to begin with.

Other than that, i'm glad that you were able to figure out what was going on without losing too much hair or sleep : ) Sean
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Balanced power WILL play games with an AC polarity tester and is the sole exception to what we think of as "proper AC power". Anything else should have a very specific hot, neutral and ground ( as far as i know ). Sean
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Max: The caps won't correct what is a design error or quality control problem with the Blue Circle PLC. If you want to use that and get good results, it needs to be replaced or repaired for proper operation. That is, if this unit doesn't take standard polarity AC and convert it to "balanced" power. I'm not familiar with this specific unit, so i'm adding that as a disclaimer. As mentioned, "balanced power" will play games with polarity sensing devices. As mentioned in another thread, "balanced power" can also undermine the design integrity on some well engineered gear. As such, adding such a "tweak" to your system may actually be detrimental to performance and / or the lifespan of the gear.

If you're interested in some alternative points of view on tweaking your AC, try reading the tweaks found on David Magnan's website. As with anything else involving high voltage & current, be careful and use some common sense. It is NOT worth getting injured or killed no matter how much better you think your system will sound after doing something that could be considered "unsafe". Sean
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Mgh: Did you ever resolve the problem that you were having with the left channel? What about the hum in your speakers that was volume sensitive? Sean
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