Hum from Phono Turntable with new Amp

[Jakesawake]

My old high-end Amplifier died and I just replaced it with a cheap one. When I set it up, I now have a bad Hum from the turntable that I didn't have with my old amp. Both my old and new amp have no phono section so I am using a Pro-Ject phono preamp, going to the CD or DVD (tried both) RCA input of the amp. I grounded the turntable to the amp chassis and the preamp chassis and neither affected the hum. The CD mode works fine and sounds good - no hum there.

My question is, could the new cheap Amp be the cause of this, or is it a new ground loop problem or something else?

 

[Verdinut]

My old high-end Amplifier died and I just replaced it with a cheap one. When I set it up, I now have a bad Hum from the turntable that I didn't have with my old amp. Both my old and new amp have no phono section so I am using a Pro-Ject phono preamp, going to the CD or DVD (tried both) RCA input of the amp. I grounded the turntable to the amp chassis and the preamp chassis and neither affected the hum. The CD mode works fine and sounds good - no hum there.

My question is, could the new cheap Amp be the cause of this, or is it a new ground loop problem or something else?

I strongly think that this new cheap amp is the problem. Can you return it for a refund and replace it with a better product?

 

[fmw]

My old high-end Amplifier died and I just replaced it with a cheap one. When I set it up, I now have a bad Hum from the turntable that I didn't have with my old amp. Both my old and new amp have no phono section so I am using a Pro-Ject phono preamp, going to the CD or DVD (tried both) RCA input of the amp. I grounded the turntable to the amp chassis and the preamp chassis and neither affected the hum. The CD mode works fine and sounds good - no hum there.

My question is, could the new cheap Amp be the cause of this, or is it a new ground loop problem or something else?

Be sure to make sure everything that needs to be grounded is grounded, particularly the tone arm. Hum is generally a grounding issue. It isn't likely the Amp is the problem. As long as it has a three prong power cord, it is already grounded.

 

[Jakesawake]

Thanks to you both for your feedback - by process of elimination I have isolated the phono preamp as the source of the hum. I've tried 1.grounding the turntable to the pre amp and 2. grounding the turntable to the amp chassis. Neither one lessens the hum. Could my 15 year old phono preamp or the cables connecting to the amp be the problem?

 

[TLS Guy]

Thanks to you both for your feedback - by process of elimination I have isolated the phono preamp as the source of the hum. I've tried 1.grounding the turntable to the pre amp and 2. grounding the turntable to the amp chassis. Neither one lessens the hum. Could my 15 year old phono preamp or the cables connecting to the amp be the problem?

I bet this is a ground loop. Something is not at true ground. Since you did not have trouble until you bought that cheap amp, that is suspect number 1. By the way, cheap gear are usually your most expensive purchases.

So we need more information. What are your amp and turntable, and what sort of AC plugs do they have? In addition what are the grounding lugs on those units.

What was your high end amp, and why did you not fix it?