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PC to Amp Interference

spin_doctor

Standard Member
Hi folks,

This is my first post, so I hope I'm putting it in the right forum and that one of you kind chaps might be able to advise me...

I'm getting a lot of interference from my PC sound card (aging Audigy Platinum) through the 3.5mm-jack-to-RCA cable into my amp (new Tangent AMP50). It doesn't matter what source I select when the PC's ocnnected to the amp, and the interference doesn't increase/decrease with the volume. When the RCA's are transferred over to the telly (42" Acoustic Solutions LCD42761F) and the amp is playing music from my N95 8Gb (again through a 3.5mm-jack-to-RCA cable) the interference disappears, so I don't *think* it's the speaker wires or the interconnect itself, but I could easily be wrong.

Can anyone diagnose the problem and provide a solution?

I've read about ferrites and mains filters (is this one worthwhile?), but I have no idea if either would solve the problem.

Any and all help would be greatly appreciated.

Many thanks,

Doug
 

namuk

Distinguished Member
Welcome :thumbsup:

what RCA leads are you using? i had an issue a while back causing feedback to sub , it ended up being the RCA lead connected to 5.1 multy in on amp.

they were bad insulated cheap leads :thumbsdow now replaced ..

also you could download latest drivers that's worth a punt:thumbsup:
 

spin_doctor

Standard Member
Thanks for the reply Namuk...! :hiya:

The interconnect is just a 1.5m lead from Maplin... Are either of these what I need:

3.5mm Stereo Plug to 2 Phono Leads > Maplin - 1.5m £9.99
High-Performance 3.5mm Jack to Twin Phono > Maplin - 1.2m £19.99

All three say they are screened, so I'm not sure what the differences really are... :confused:

Any recommendations gratefully received! :D

If it's any use, the interference itself sounds just like the pump, fans (undervolted with a Sunbeam Rheostat Module), HDD's and DVD-RW when they're spinning. If I turn the fans up, the interference changes accordingly.

Cheers,

Doug
 

namuk

Distinguished Member
Thanks for the reply Namuk...! :hiya:

The interconnect is just a 1.5m lead from Maplin... Are either of these what I need:

3.5mm Stereo Plug to 2 Phono Leads > Maplin - 1.5m £9.99
High-Performance 3.5mm Jack to Twin Phono > Maplin - 1.2m £19.99

All three say they are screened, so I'm not sure what the differences really are... :confused:

Any recommendations gratefully received! :D

If it's any use, the interference itself sounds just like the pump, fans (undervolted with a Sunbeam Rheostat Module), HDD's and DVD-RW when they're spinning. If I turn the fans up, the interference changes accordingly.

Cheers,

Doug

That was type of lead i did throw away Twin Phono to 3.5mm Stereo Jack Lead > Maplin

I replaced it with this i got it for around £6.95 +postage have a search and cured interference Monster Interlink 100 Minijack 2m (6.6') on eBay, also, Audio Cables, Cables Connectors, Computing (end time 23-Jun-09 13:58:06 BST)


but after what you this said sounds like the leads could be picking up the motor ..

have you disconnected all leads then tried? if interference diserpers then connect one lead at a time ..
 

spin_doctor

Standard Member
I only get interference when the RCA's are connected to the amp and the PC is on. If the RCA's are plugged into the telly (which is right next to everything else), there's no problem at all...

I'll swap it over for the £10 Maplin ones and see if they're any better, and I'll post back with the results...

Thanks!

Doug
 

spin_doctor

Standard Member
Well, I got the £10 Maplin leads and tried them out.

Still in exactly the same situation...:(

I think these are the same sort of spec yours are:
  • 24K hard gold-plated connectors
  • High quality, oxygen-free copper (OFC) multi-strand cable
  • Ideal for PC sound cards and personal CD, MD and MP3 players
  • Colour-coded connectors for easy identification
  • Pure copper braid and aluminium foil dual shielding to block RFI/EMI interference
...so I don't think I have the same problem.

Any other suggestions? Really want to be able to use my amp connected to the PC! :confused:

Many thanks,

Doug
 
Last edited:

namuk

Distinguished Member
:( unless the pump has a earth problem it could be on it's way out .. also the sound card were is it in system? did you try to relocate to bottom of case?


Well, I got the £10 Maplin leads and tried them out.

Still in exactly the same situation...:(

I think these are the same sort of spec yours are:
  • <LI class=moduleBulletText>24K hard gold-plated connectors <LI class=moduleBulletText>High quality, oxygen-free copper (OFC) multi-strand cable <LI class=moduleBulletText>Ideal for PC sound cards and personal CD, MD and MP3 players <LI class=moduleBulletText>Colour-coded connectors for easy identification
  • Pure copper braid and aluminium foil dual shielding to block RFI/EMI interference
...so I don't think I have the same problem.

Any other suggestions? Really want to be able to use my amp connected to the PC! :confused:

Many thanks,

Doug
 

spin_doctor

Standard Member
I'm pretty sure the pump's ok... It's not very old.

I did also hear sounds corresponding to mouse clicks, menu's opening up, scrolling etc. within the interference.

Can anyone advise if one of those mains filters or ferrite rings might help?
 
Last edited:

spin_doctor

Standard Member
Hi folks...!

Thought I'd just update this thread with my solution.

It turns out that my problem was due to a ground loop. So I got myself a Xitel ground loop isolator and hey presto... problem solved!

Thanks for all the suggestions folks. :smashin:

Cheers

Doug
 

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