Those in-the-box RCA cables...

[guermantes]

Hi!
Newbie on the forums here, with a setup mix of turntable and speakers from my teenage years (1985) with new entrylevel hifi. (The vertically standing DAC takes lossless computer music over toslink, I am not sure the DAC was worth it but the toslink simplifies a lot).

I currently have generic in-the-box RCA cables connecting my turntable, RIAA stage and amp. It's all crammed inside a cabinet behind the amp and I guess prone to interference, though I have not heard strange noises until now. Last week I installed a 5V computer fan in the back of the cabinet. DIY! Today I noticed a fluttering/stuttering noise when I switch to turntable channel, play nothing and turn the volume up to 12 o'clock (I usually listen around 9-10). I have not changed the cables, but I did not use to have this noise.

The noise can be heard here (the fan was disconnected when I recorded this):

Is this noise due to the cheapo cables being interfered with after having been placed differently after the fan installation? Is it because they lack shielding that this happens?

Or could something else be going on?

 

[slipperybidness]

First guess is that you nailed it. Cheap cables picking up interference!

This is particularly more problematic on phono cables than other sources. The signal coming out of the phono cart is VERY small as compared to ANY other signal in the chain. That means that the signal must be amplified MORE than other signals to get the final output level. Guess what, when the signal is amplified more, the noise is also amplified more.

1 of my turntables had too much "buzz" in my setup. In particular, I came to a spot on my install where my RCA phono lines had to cross a power cable. I swapped in a high quality twisted pair and shielded RCA cable, and problem solved!

 

[guermantes]

Ok, thanks! I'll get some shielded cables then.