Hum in amplifier: help needed!

[cchean]

Hello everyone: I have a vintage Mission Cyrus 2 integrated amplifier that is working fine but when switched to the phono input and the volume control turned up, the hum is terribly loud. When playing a record, most of the hum is masked by the music but I could not believe how loud it was when I heard the amp without a record being played. The hum is even louder when the phono inpuit is set to MC. Since I use it with a Rega Planar 3, the Rega doesn't have the ground lead. Is it possible that it is the lack of the ground lead that is causing the problem? I use my audio setup with a Chang Lightspeed line conditioner although my house mains is not earthed. Could it be that the amp is faulty? How common is this problem? Any advice will be appreciated. Thanks.

[Resident Loser]

...disconnect the TT feed @the amp input...does the trouble remain or has it gone away?
If it's gone, the tbl is with the TT/cart/RCA connectors...if the trbl remains it's the integrated...Are you using shielded ICs? Hums can be caused by grounding or lack thereof...situation dependent

jimHJJ(...divide and conquer...)

[risabet]

Hello everyone: I have a vintage Mission Cyrus 2 integrated amplifier that is working fine but when switched to the phono input and the volume control turned up, the hum is terribly loud. When playing a record, most of the hum is masked by the music but I could not believe how loud it was when I heard the amp without a record being played. The hum is even louder when the phono inpuit is set to MC. Since I use it with a Rega Planar 3, the Rega doesn't have the ground lead. Is it possible that it is the lack of the ground lead that is causing the problem? I use my audio setup with a Chang Lightspeed line conditioner although my house mains is not earthed. Could it be that the amp is faulty? How common is this problem? Any advice will be appreciated. Thanks.

Rega's are known for this problem, they have unsheilded motors which interact with the cartridge to cause hum. Check by unplugging your TT from the wall outlet, with the amp off, turn the amp on. Is the hum gone? If it is than the TT motor is the problem. If the hum is still there than unplug the TT leads to the amp, with the amp off, turn the amp on. Is the hum gone? If so than it is still your TT, if not, if the hum is still there, the problem is in your amp.

I don't know how to cure the Rega hum problem, you might try floating any grounded plugs with a 3 to 2 cheater plug. Check with Rega for any possible fix.

Good Luck!

[Glen B]

I use my audio setup with a Chang Lightspeed line conditioner although my house mains is not earthed.

Don't you mean your outlets are not grounded ? It would be a serious violation to not have your household electric supply grounded at the service panel/fuse box. The noise reduction technology in the Chang line conditioners will work without a ground, however, you will not have line-to-ground and neutral-to-ground surge protection, only line-to-neutral protection.

[Arc45]

Just out of curiosity are the TT and AMP on different cirtcuits? If so you may be getting a ground loop. Try putting them on the same circuit. My 2 cents worth.

[RGA]

Also be careful of any Television Cable coming into your home - most hum problems are cause by television cable and you can get the tv company to make sure they have grounded whatever it is they need to ground. I had a horrible hum from My Sugden and Arcam integrated's and had the cable company out and boom hum is completely gone. You can buy a device for about $10.00 that attaches to the end of the cable and then you connect that deivice to the tv or vcr. That worked well too(It's not an RF device but I forget what it's called).

Phono devices are super sensitive it would seem. Interestingly my ASL MG Head tube amp never experienced the hum issue. strange.

[malibushirl]

Do you have a cable tv feed into this system at any point or is this stand alone two channel?

Every audio system that I have owned that included an amp and had cable tv gave me ground feedback loop. Yes, even if I had the cable tv connection grounded from outside.
Cheap fix, 2 prong to thre prong converters on your amp and other equipment.
Better fix, look into a line protector from Brick Wall(search google for them)this will cost you about 200.00 dollars but will elimate the issue.

If this is stand alone 2 channel system and no cable tv in the mix then still give the old 2 prong to 3 prong converter a try. If it works then look to moving to the more expensive lline conditioner fix from Price Wheeler's Brick Wall product

Also be careful of any Television Cable coming into your home - most hum problems are cause by television cable and you can get the tv company to make sure they have grounded whatever it is they need to ground. I had a horrible hum from My Sugden and Arcam integrated's and had the cable company out and boom hum is completely gone. You can buy a device for about $10.00 that attaches to the end of the cable and then you connect that deivice to the tv or vcr. That worked well too(It's not an RF device but I forget what it's called).

Phono devices are super sensitive it would seem. Interestingly my ASL MG Head tube amp never experienced the hum issue. strange.