Hi,
I see this is an old thread but I had a huge breakthrough today and felt like sharing. I have an Arcam Alpha 9 CD player from 1998/99. After reading a lot on the web it seems this is a very good CD player. It has a very good reputation. I guess I do better with CD players than picking stocks. Doh!
Anyway, I've always been happy with my CD players sound but in the past couple of years I've noticed a HUM coming from inside the unit. Even when powered off. If I pull the plug, the hum goes away. I happened to be talking to someone and they said they've taken bicycle inner tube rubber and cut little squares. Then they open the unit and place the rubber squares under the transformer and it quiets down the hum.
Hummmm. I started thinking...
Next thing I knew I had a Phillips screwdriver in hand and my CD player was on my kitchen counter top. I just wanted to "look inside" to see whatever I could see. For some reason I either got really stupid or grew gigantic balls, either way the next thing I'm searching the house for something "rubber."
I found some non-slip rubber matting that I used on a bathroom rug to keep from sliding around. It has a "tight weave" meaning you can hold it up and see holes and light coming through, but the holes are small, (
now we know how many holes it takes to fill the Albert Hall).
Anyway, next I started removing screws so I could lift up the green printed circuit board (PCB) that the transformer is attached to. I cut two rectangles of the rubber matting and doubled them up - one on top of the other. I placed the rectangles under the transformer area such that when I screwed the PCB back into place I had to screw through the rubber.
So what I basically did is dampen the vibrations. The transformer still hums and vibrates BUT the vibrations are not being carried all through the PCB and metal chassis. Understand?
The rubber rectangles are pushed up against the back of the green PCB on the bottom, underneath the transformer. The rubber also covers PCB screw holes and I have some wedged between the side of PCB and the metal chassis/case cover.
So here's the result. Yeah, I still hear some hum, but it's MUCH softer and I really have to have my ear next to the CD player to hear it. But the reason I'm writing all this is because the freaking sound blew me away. I mean WTF? The soundstage exploded. I never had front-to-back imaging before, now I do! Everything sounds clearer, more relaxed and vibrant. I hate talking like an audiophile nerd, but the sound transformation is amazing.
The only thing I can figure what happened was
all that hum and vibration was traveling through the whole CD player. It must have interfered with the laser reading the bits from the spinning disc. Keep in mind I thought my CD player sounded pretty good. I had no idea how crappy it must have sounded. None of my music friends ever mentioned anything. I bet they will now.
So, when you hear a hum and you think it's mechanical coming from inside your components, think about what these vibrations could be affecting. In the case of a CD player the vibrations affect a LOT!
