Amp "Hum" caused by dimmer switches

Before you give up, you should try the AudioPrism Quiet line filters. They look like battery eliminators for a CD player, often referred to as a wall wart.

Many household appliances (and especially dimmer switches) dump loads of noise into your electrical system. Even when the problem is not as obvious as in your situation, this noise creeps into every component in your sound system and effects performance. I had a totally quiet system, and bought a set of Quiet Lines at CES just for the experience. After having them in my system for a week, I removed them, thinking I could do just as well without. That idea lasted just about to the end of the next piece of music, whereupon I replace them and they have remained ever since.

These filters are inexpensive, and can be moved from one AC outlet to another, to determine the best results. They come in a pack of 8 pieces at retail $300.00. You should be able to find a dealer that would let you try a set over one weekend to see if they fix your problem. If they do, this would be less expensive than reselling and shipping the amp that you are otherwise happy with.

Khaki8 and Brentski71. Yes, I am using a line conditioner and have fourteen dedicated runs to my audio system as well. I did not have any noise problems before the line conditioner or the Quiet Lines, however there was a performance gain with each of these.

I witnessed an active demo showing Quiet Lines plugged into a noisy outlet on the main floor at CES, whereupon some very obvious buzz and hum was reduced to inaudible. This was what made me think about your situation. There were hundreds of electrical powered things going on, not to mention the lighting. I thought that if it worked there, maybe it would help you.

The comments by Bob bundus are probably correct. The quality of the dimmer is a likely source of the hum. I have no way of knowing which of you (could/ would?) replace this noisy dimmer yourself. Electricians fees and markup on parts could easily run half the price of a set of Quiet Lines. This is why I suggested getting a set for trial, before investing any money.

If you have no other source, I would let you try my filters and see if it fixes your problem. I would prefer shipment by air each way though, so I could return to normal pretty quick.

Khaki8 , I bought my Quiet Line Filters at CES, after I heard the demo,

Sean, I went into a lot of detail about electrical in another post, so won't cover all points. The short version is that I had the electric company do a dedicated transformer, run 220 three phase and install a 750 amp straight thorough box (amp probe meter rather than disconnect type). Then I put all digital on lower leg, all analog on higher leg, and third phase to air conditioning system. The fourteen dedicated breakers are all 10 gauge with a separate TNN ground to true earth. The star ground does not even see the rest of the house.

As far a comments about dimmers, I too have none in my home. The reason I answered the question the way I did was the fact that the poster seemed ready to sell his amp rather than do away with the lighting.

Difficult to know what is important to anyone's family. Add to that, the filters did help my system, even when I had no problem. Looked like an inexpensive option, compared to selling gear. As always, will not fit everyone's needs.

The before and after story is that all the electrical work produced an unmistakable upgrade in performance in every piece in the system. It was obvious from the first few notes, and it got better after some burn in time.

The disappointment comes in the fact that it does not always sound like 3:00 AM Sunday morning. I know what you are describing, and only wish that could be.

The sound is always better than it was before, but still improves during the quiet times you are talking about. A good description would be that the electrical work moved the entire system up, but was unable to overcome the laws of physics (IE: You can still hear the noise, hash and crud on the electrical lines till everyone has finally gone home to bed.)

The CT metering was obtained, only after contacting a supervisor at Texas Utilities. My photo studio is built on the back of my home, and requires 200 amp service. I told them that the house with its normal 200, plus the photo studio's 200 was close enough to go with the big box. They provided at no charge and I paid the electricians to do the install. If someone were to pull my meter, the service would continue without being recorded. Therefore, I have the only meter panel in the neighborhood with a TU keyed padlock installed.

My main reason for wanting this type of box is the fact that the standard version has a huge coil of wire with prongs that plug into your service panel. That way, if the meter is pulled, the service is disconnected. The problem with this is the stereo system is going through that crappy meter and those strange plugs and wires. The panel I have uses solid 8 gauge copper rods to connect the drop to the interior. The meter simply clips around these rods, and reads the usage like an Amprobe would.

All in all, the house has 4 breaker boxes. One is strictly for 220 AC, which branches off with 8 gauge to a sub panel that supplies 220 to my stereo system. I choose Hubbell twist locks and they are floor mounted. All the remaining stereo runs (12 others), are to Hubbell hospital grade with special ground (no strap).

The Photo studio has two panels, one for normal lighting and household outlets, and a heavy duty panel with 10 dedicated runs for photographic lighting and equipment. The remaining panel is a 200 amp Square D which supplies the home, regular stuff like hair dryers and lights.

The requirement for this service was 00 (double zero) drops from the transformer and service. The copper I wanted was available, but required an additional service pole in my back yard to support the additional weight. Calculations by TU said that the run in copper would pull the entire service off the side of my house. I did not want the creosote pole by our swimming pool, so I dropped this idea and went with the standard 00.

The three phase was already in the alley, and the laws concerning utility service in Texas are that the homeowner "must require" the service to obtain it. If it is required, then they must provide the service without penalty. I simply bought a 5 ton Lennox commercial air conditioner for my home, which is 220 three phase, and the drop was free. My electric bill dropped, due to the greater efficiency of the Lennox unit, combined with the greater efficiency of three phase.

The ground issue seems to not be a problem. The household ground is on a 8 gauge run to the copper water supply pipes and then to a big copper rod in the earth provided by the utility. My stereo system is grounded to three copper rods, one under the house, and two outside. They are in a large triangle, and are tied together. My VOM does not show any leakage, and the system is dead quiet.

The first reaction for everyone is that this whole thing is a bit over the top. However, if you consider the investment in stereo gear, the money saved on air conditioning, and the availability of 220 for European goods (should I wish), plus improved meter panel performance, it was a bargain. To put this in perspective, the completed cost was less than the retail price of three Purist Audio Dominus power cords (which I also use). My only regret is not having done it sooner.