Buzzing in Exactpower SP15

Mghcanuck, The AC offset killer is only good for 10 amps. I really would not know where else to go until Exactpower releases their little correction unit. That will be good for 15 amps.

Although I won't tell you that the Offset Killer won't work. I have never tried it.

Maybe throw up a thread re: DC offset correction?

Interesting topic. I have a Blue Circle MR1200 balanced power line conditioner/distributor and it too has a tendency to buzz/hum audibly. The noise appears at intervals of between 15 to 30 minutes, it starts out low and increases in volume over about 30 to 60 seconds then subsides into silence. I have been told by Blue Circle that the AC from the wall must be particularly dirty and/or it may be due to the on/off cycling of the furnace. They say the noise is indicative of the balanced transformer working hard to clean up the AC.

Are there any devices currently on the market to clean up DC offset, if this is what I'm experiencing in my home? The company that makes the Ah! NoeToeb 4000 CD player also sells a device called an AC Offset Killer, and I wonder if its just misnamed. Any thoughts?

Interesting to hear that others have the same 'problem'. My system is silent except for this....

Sugarbrie, when you really think about, as unfortunate as it may be, we are ALL having to solve the electrical utilities shortcomings!

It's a vicious little circle, isn't it?

There...Buscis took the time to explain the problem I was referring to very well. I did not know exactly how the Exactpower worked. But a buzzing unit or transformer in any piece of gear is almost always a problem with DC offset from our friendly power utility.

If the problem is not bad, sometimes a dedicated line will be enough, since it removes other home appliances from the circuit. But this case must be very bad. (ie, the gear buzzes, so you get a power correcting device, which then buzzes itself.)

Nice to hear that Exactpower is now working on the input side of their devices, after perfecting the output side going to the gear. It is sad that they have to solve the electrical utility's shortcomings also.

BTW, The Exact Power units are being revised to correct this condition. The revision should be incorporated into the units being released later in the year. It seems the AC coupling portion of their AC correction circuit design is lacking the ability to compensate for extraneous amounts of DC offset present in the AC signal.

It does in fact compensate for root and residual DC offset, but it seems many of us (Thanks to our utility companies), are experiencing some very high levels of DC signal in our AC. Some way in excess of +/- 12v. Remember, the EP is designed to correct an AC power waveform. Although obviously, they are using DC signal to power the digital/reference frequency portion of their corrective circuit.

Hopefully any revisions or upgrades can be incorporated into our existing units. I'm gonna kinda' sit back, give them some time and let them do their homework. I'm sure that these units will just continue to improve. Hell, mine doesn't even have the digital filtered outlets. I'm using an outboard passive device to do that.

Mine is a very early unit (Nov.2002). So, just look at what they have done in the last year. After they get done tweaking, I will probably replace mine with their latest unit with all revisions incorporated. Possibly even the 20 amp (if they ever release it).

Stay in touch with your EP dealer for the availability of this little corrective device/filter. Hopefully it will resolve any issues. Ed.

Howard, Every once in a while I experience the same with my EP. It's not audible through the system and has no affect on the music, it's just a physical/mechanical buzzing. And that's only on occassion.

I have discussed this with EP and they told me the cause may be due to DC offset on the lines. Soon, they will be releasing a small filter/correction device that is designed to be plugged into the same outlet as the EP. It will supposedly correct this condition. So obviously, it's not just us experiencing this problem.

Although, the EP does such an incredible job with everything else, I have learned to ignore it. Keep in mind, they are on the ground floor with these units. It seems that they are resolving any issues as they arise. I love my EP-15. And just to remind you of how much you love yours, unplug it, and go directly into the wall.

Suddenly the minor buzzing will become irrelevant.

My compliments to the boys at EP. They really did a great job with this unit.

Sugarbrie,
The SP15 A is Exact Power's Balanced Power product and does neither adjust voltage nor power. This is done by the EP15A, which stabilizes the incoming power and provides stable voltage at its outputs. I experience the same slight buzz with my SP15A, the SP15A being plugged into the EP15A. If I play music, I cannot hear this, however. A dedicated line does probably not solve the problem, as this is what e.g. I already have. Actually, I think that the buzz is simply the result of the natural work of the transformers of the SP15 A, which you hear bcs the unit is not islolated acoustically. From a musical point-of-view, however, the addition of this combo was one of the most noticable improvements I made in my system. I had the EP15 A first, then added the SP15A, although some said the SP15A would improve performance only marginally. Fortunateley, my experience proved to be different.

I could go easily into a very long explanation. Trying to put it simply......

The Exactpower adjusts the voltage and power coming out of it going to your gear. Unfortunitely the quality of the voltage and power going into the Exactpower from the wall is taxing the ability of the of the SP15 to adjust the power.

Dedicated lines may solve the problem if you want to go that far. Or just don't plug the EP15 and SP15 into the same duplex.