You are here

Sudden onset mains hum but only when I load a particular plugin.

All about the tools and techniques involved in capturing sound, in the studio or on location.

Moderator: Moderators

Sudden onset mains hum but only when I load a particular plugin.

Postby mjmorris » Sun Nov 29, 2020 7:13 pm

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
mjmorris
Poster
Posts: 15
Joined: Fri Sep 10, 2010 12:00 am
Regards, Mike.

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby blinddrew » Sun Nov 29, 2020 7:40 pm

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.
User avatar
blinddrew
Jedi Poster
Posts: 12907
Joined: Sun Jul 05, 2015 12:00 am
Location: York
Ignore the post count, I have no idea what I'm doing...

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby mjmorris » Sun Nov 29, 2020 8:17 pm

blinddrew wrote: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.
mjmorris
Poster
Posts: 15
Joined: Fri Sep 10, 2010 12:00 am
Regards, Mike.

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby Hugh Robjohns » Sun Nov 29, 2020 8:33 pm

Fuzz or compression effect in the signal path? Vintage amp model with built in hum effect?
User avatar
Hugh Robjohns
Moderator
Posts: 29544
Joined: Fri Jul 25, 2003 12:00 am
Location: Worcestershire, UK
Technical Editor, Sound On Sound

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby mjmorris » Sun Nov 29, 2020 8:46 pm

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

Time for a beer and a think.
mjmorris
Poster
Posts: 15
Joined: Fri Sep 10, 2010 12:00 am
Regards, Mike.

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby The Elf » Sun Nov 29, 2020 9:27 pm

...or has it crashed, or is in a loop? Do you get audio through it?
User avatar
The Elf
Jedi Poster
Posts: 15740
Joined: Tue Aug 14, 2001 12:00 am
Location: Sheffield, UK
An Eagle for an Emperor, A Kestrel for a Knave.

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby CS70 » Sun Nov 29, 2020 10:08 pm

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?
User avatar
CS70
Jedi Poster
Posts: 6928
Joined: Mon Nov 26, 2012 1:00 am
Location: Oslo, Norway
Silver Spoon - Check out our latest video and the FB page

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby mjmorris » Sun Nov 29, 2020 10:40 pm

CS70 wrote:You are staying away from the computer screens, right?

:D Oh, yeah. Been playing single coils for fifty years - I stay away from everything...
mjmorris
Poster
Posts: 15
Joined: Fri Sep 10, 2010 12:00 am
Regards, Mike.

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby CS70 » Mon Nov 30, 2020 9:18 am

mjmorris wrote:
CS70 wrote: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.
User avatar
CS70
Jedi Poster
Posts: 6928
Joined: Mon Nov 26, 2012 1:00 am
Location: Oslo, Norway
Silver Spoon - Check out our latest video and the FB page

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby mjmorris » Mon Nov 30, 2020 5:10 pm

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.
mjmorris
Poster
Posts: 15
Joined: Fri Sep 10, 2010 12:00 am
Regards, Mike.

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby Martin Walker » Tue Dec 01, 2020 1:15 am

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
User avatar
Martin Walker
Moderator
Posts: 16925
Joined: Wed Jan 13, 2010 9:44 am
Location: Cornwall, UK

Re: Sudden onset mains hum but only when I load a particular plugin.

Postby mjmorris » Tue Dec 01, 2020 11:23 am

Martin Walker wrote: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.
mjmorris
Poster
Posts: 15
Joined: Fri Sep 10, 2010 12:00 am
Regards, Mike.