SOUND ON SOUND

[mjmorris]

Guitar -> DI box -> EMU 0404 USB -> Reaper

Listening to the untreated guitar directly into Reaper there's no mains hum. Load up Amplitube 4 and straight away there's a buzz. Happens with all the guitars I've tried, both single coils and humbuckers.

Amplitube has a neat little feature that allows you to switch the various modules (Stomps, Amp, Cab & Rack) in and out of the signal path. Interestingly, when I switch off the Amp module the noise goes away.

This system has been working noiselessly for me a long while now; just today it's started buzzing. I've not changed anything and I've checked all the cables and sockets, etc.

The one thing that puzzles me is why a plugin should generate mains hum.

Any ideas gratefully received

[blinddrew]

Not something as simple as amplitude having a 'noise' setting that you've accidentally flicked on?
Otherwise i'd start by checking the gain staging throughout the chain.

[mjmorris]

Not something as simple as amplitude having a 'noise' setting that you've accidentally flicked on?
Otherwise i'd start by checking the gain staging throughout the chain.

No noise setting as far as I can see. Gain on the interface is set to give me about -18db up to -12db into Reaper. Input level in Amplitube is set at 0.0db; the input meter barely moves. The output from Amplitube is again set at 0.0db; it reads about -11db on the Reaper Master Track.

[Hugh Robjohns]

Fuzz or compression effect in the signal path? Vintage amp model with built in hum effect?

[mjmorris]

Nope. I loaded up a clean amp emulation, all the controls at 5, no stomps. Same result.

Time for a beer and a think.

[The Elf]

...or has it crashed, or is in a loop? Do you get audio through it?

[CS70]

My money would be on the amp stage simply amplifying existing noise in the chain before it. It almost invariably is, for these kind of issues.

You are staying away from the computer screens, right?

[mjmorris]

You are staying away from the computer screens, right?

:D Oh, yeah. Been playing single coils for fifty years - I stay away from everything...

[CS70]

You are staying away from the computer screens, right?

:D Oh, yeah. Been playing single coils for fifty years - I stay away from everything...

A man after my own mind. :)

Something a bit unusual worth checking is the USB cable of the audio interface. Some rare times it may introduce noise. Also same rig, different computer if possible, just to eliminate stuff that's not related to the music gear.

[mjmorris]

I decided to just pull everything out and clean all the plugs and sockets rather than just checking they were all tight and, wouldn't you know it, I put everything back together and the hum has gone.

If it comes back I still won't know what's causing it but I'm happy just to kick the can down the road for the moment.

Thanks for everybody's input, it was very helpful.

[Martin Walker]

Pleased to hear that your hum is in the past.

With a 'cure' like that I can never decide if I'm pleased or angry - I suppose it depends whether or not the hum comes back to haunt me ;)


Martin

[mjmorris]

Pleased to hear that your hum is in the past.

With a 'cure' like that I can never decide if I'm pleased or angry - I suppose it depends whether or not the hum comes back to haunt me ;)


Martin

Exactly. I expect this will come back and bite me but I'm in CBA mode at the moment. A product of my advancing years, perhaps.