Issues with new amplifier

[Lord Flaber]

Hey everyone,
Okay I’m having an annoying audio issue with a new amplifier that I bought as an upgrade to my old one which was an Denon PMA520AE. Okay, before I get to the issue I begin with the setup that I’m on.
Desktop:

• 
  ■Core I5 6600K
  ■ASRock H110M Combo-G S1151 mATX Intel Motherboard
  ■Ballistix Sport LT 8GB Single DDR4 2400
  ■AMD R9 290X
  ■Sound Blaster Z PCI

Amp:

• 
  ■1978 JVC JA-S77

Okay, with that out of the way, I begin with the issue. With the Denon amplifier that I use to have, it was connected with a pair of RCA shielded cables to the ‘speaker out’ port. Never had any issues with this at all, only once I’ve change the amplifier. With the JVC Amp, I have interference all over the place (Humming and Buzzing sounds) The sound changes once I’m scrolling the mouse, loading anything or even worse once I play games.
I’m not sure what’s causing the issue. I first suspected that it could be a ground loop issue, but it could be EMF from the graphics card since the sound card is right next to it. It could also be the design of the amp itself or an issue with the amp.

What I’ve done to fix it:

• 
  ■Changed the cables
  ■Disconnected the PC to the amp and only pugged in the turntable (To diagnose if it’s an issue with the amp itself)
  ■Tried the on-board sound (It’s worse)
  ■Used an external USB sound card (It’s the same)

I’ll be grateful for any assistance on this bloody issue since it’s driving me mad!

• 
  

 

[americanaudiophile]

Does the JVC make noises when you connect another source?
You may need to isolate the audio output from the PC.
https/www.crutchfield.com/p_127SNI1/PAC-SNI-1.html?tp=61807&awkw=75640380625&awat=pla&awnw=g&awcr=47623509025&awdv=c&awug=9004455
http/www.jensen-transformers.com/product/ci-2rr/