Rehearsal rooms under railway arches - interference

[Al Krow]

We rehearsed recently in a rehearsal studio in Elephant & Castle located below a railway arch with an active railway line overhead.

 

There was unfortunately a lot of interference for the guitarist. The venue would otherwise be great for the band, being centrally located for us and accessible by public transport. 

 

My understanding is that electric guitar pick-ups convert a modulated magnetic field being generated by the overhead railway lines into an electrical signal and then amplify it, and will be made worse if long leads, which act as an aerial, are being used.

 

Is there a piece of kit that a guitarist could use to neutralise the impact of the overhead railway line (other than playing acoustically, haha)?

 

Cheers, Al

[Suburban Man]

More likely poor earthing somewhere - possibly the mains sockets that you were using.  Would going wireless be an option?

[Nothingman]

I’d just be happy if I could find a rehearsal space. 
 

[tauzero]

Did your bass not also suffer? And if not, is it an active or a passive bass?

[Frank Blank]

I've had a couple of basses that used to pick up taxi radio chatter but only when the active batteries were running low.

[itu]

If the field is really magnetic over electric, your chances to shield anything are low. But if only the g-word is affected, start from checking the placement of the amp, and then the instrument. Maybe you have to tilt the amp to its side, but be creative.

 

(When I was working with electronic compasses, a customer was asking to shield the circuitry from electric fields, because train drive affected the compass' performance...

 

If it is unclear to someone: electric field always produces magnetic field, too. Magnetic fields are possible without electric fields, like with permanent magnets.)

[PaulThePlug]

Try a different plug socket...

Any Fluorescent Lighting or Dimmer Switches? 

[Rich]

I remember reading an article in a rail industry mag many years ago, where TI-21 audio-frequency train detection track-circuits were having a similar effect on a studio in a railway arch. I can't for the life of me remember what the solution was though.

[Al Krow]

1 hour ago, tauzero said:

Did your bass not also suffer? And if not, is it an active or a passive bass?

 

Yeah the bass seemed to be fine -  it's an active bass. I was going through a provided amp whereas the guitarist was going through the PA (which is what we were going to do for everyone at the gigs the following weekend - and which were thankfully really fine). We wondered whether it might have been the PA, but he got the same interference going through my bass amp with his guitar.

[Al Krow]

 

2 hours ago, Suburban Man said:

More likely poor earthing somewhere - possibly the mains sockets that you were using.  Would going wireless be an option?

 

I was wondering whether wireless might help and I can certainly take along a couple of "bugs" for the guitarist to use.

 

29 minutes ago, Rich said:

I remember reading an article in a rail industry mag many years ago, where TI-21 audio-frequency train detection track-circuits were having a similar effect on a studio in a railway arch. I can't for the life of me remember what the solution was though.

 

My concern was that initially folk were saying "no easy remedy because electric guitar pick-ups are designed to convert a modulated magnetic field into an electrical signal and then amplify it."  

 

But thinking this through what's likely happening is that the guitar pups are picking up the vibration of the strings above them (obviously a good thing, haha!) and also picking up the ambient EM field from the railway lines. I guess if we were desperate to use the studio then we could try some shielding over the strings a bit like what Rickenbackers have? Unfortunately our regular guitarist is the least keen on the new venue as it's a bit less convenient for him, so maybe difficult to get him to think about such a mod.

 

Are there any guitars with such shielding over the pups as standard?

Edited August 9, 2023 by Al Krow

[fretmeister]

Is it a guitar with single coils?

[Al Krow]

3 minutes ago, fretmeister said:

Is it a guitar with single coils?

 

Good question! I guess the suggestion here is that a humbucker style pup may help?

 

[fretmeister]

Might do.

[Downunderwonder]

2 hours ago, Al Krow said:

his guitar

is obviously the common denominator, along with his lead and him.

 

You could have him stand in a wire cage or use a humbucker pickup.

[matski]

I once had a recording session in a studio under a railway somewhere in London. We had no issues with electrical hum, just the rumble of the trains passing over our heads every now and then. Ironically, we had the bright idea of trying to record the train rumble, but sod's law decreed that whenever we had a mike ready no trains would pass.

So we recorded the Space Invaders machine in the hallway instead

[toneknob]

tin-foil hat?

 

otherwise I'm delighted to hear that there's a functioning rehearsal room in SE London. Can you share details please?

 

[Waddo Soqable]

If its at Elephant and Castle (assuming it's been running a long time) I pretty much must have rehearsed there at some point.

Can't say I've ever noticed any funny electrickery interference stuff going on playing in the numerous "under the arches" type places I've been to, Backstreet at Holloway springs to mind and Allen Gordon's of course. 

[Dan Dare]

The only time I've noticed this was in a rehearsal room in West London, which was adjacent to the District and Piccadilly lines. The back wall of the studios was right next to the tracks and pretty much at the same level (you could hear the trains rumble past). As power to the underground is at track level, the live rails were probably only a few feet from where we were. There was a definite buzz through the equipment.

 

Never noticed it at the rooms under the arches on the Holloway Road, but the line there is overhead powered. The line above the old Allan Gordon rooms in Leyton wasn't electrified at the time I used it. It's now overhead power, too.

[Jo.gwillim]

Two thoughts

Have you tried plugging the guitar into the bass amp and vice versa, that should tell you whether it's the guitar or amp.

Second thought if it is a single coil guitar pickup if there's more than one switching them both on with a selector switch/blend knob could create a sort of humbucker. My jazz was picking up horrendous buzz from the stage lightning until i turned both pickups up.

Sorry if these points have been covered already haven't read the entire thread.

[Al Krow]

4 hours ago, Jo.gwillim said:

Two thoughts

Have you tried plugging the guitar into the bass amp and vice versa, that should tell you whether it's the guitar or amp.

Second thought if it is a single coil guitar pickup if there's more than one switching them both on with a selector switch/blend knob could create a sort of humbucker. My jazz was picking up horrendous buzz from the stage lightning until i turned both pickups up.

Sorry if these points have been covered already haven't read the entire thread.

Yup both points covered earlier, but cheers anyway. We're gonna give the humbucker suggestion approach a shot next time around. 

[NHM]

Plan your rehearsals for strike days?

[Al Krow]

2 hours ago, NHM said:

Plan your rehearsals for strike days?

Outstanding suggestion.

 

I think it would only work if they switched the power to the rails off though, which would make sense, but... 

[peteb]

On 09/08/2023 at 18:42, Al Krow said:

We rehearsed recently in a rehearsal studio in Elephant & Castle located below a railway arch with an active railway line overhead.

 

There was unfortunately a lot of interference for the guitarist. The venue would otherwise be great for the band, being centrally located for us and accessible by public transport. 

 

My understanding is that electric guitar pick-ups convert a modulated magnetic field being generated by the overhead railway lines into an electrical signal and then amplify it, and will be made worse if long leads, which act as an aerial, are being used.

 

Is there a piece of kit that a guitarist could use to neutralise the impact of the overhead railway line (other than playing acoustically, haha)?

 

Cheers, Al

 

I wonder if it's the same studio where I used to rehearse forty or so years ago? 

 

Funnily enough, we had the same problem last night playing a gig in a club in Manchester under a railway arch. There was a lot of interference for the guitar player's Les Paul, while my passive jazz bass was OK if I kept the volume on full for both pickups (a lot of noise if I turned down one pickup). It probably would have been better if I had used an active bass, but there's not a lot you can really do. We just ignored it and the noise tends to get lost when the band is playing. Just remember to mute everything when its not in use. 

 

[itu]

I've seen humbucking systems that are built to the pickguard to reduce single coil hum. Still the instrument acts and sounds like a single coil.

[Al Krow]

Just now, itu said:

I've seen humbucking systems that are built to the pickguard to reduce single coil hum. Still the instrument acts and sounds like a single coil.

Sounds sophisticated? Is there a pedal that does the same thing?