pucho812

buzz buzz buzz....
« on: October 25, 2019, 02:58:27 PM »
Sometimes people do not want to listen.
We have a guy with a fractal guitar fx box and it is connected via it's balanced out to a pair of powered speakers.
He swears up and down there is an electrical issue because when he connects his epiphone 335 because there is a huge amount of ground hum/buzz. I have heard it and can confirm it is the case. The guitar has coil taps and what is perplexing to me is that when in hum bucker setup with the pickups, there is buzz. making them single coil and the buzz level does not change at all.

If the guitar is not plugged into the fractal, it's quiet as a church mouse. I can assume the fractal is grounding out the inputs to prevent such things.
If we use a different guitar,  say a takamine acoustic with internal pickup, there is no buzz.|
I am convinced there is a wiring issue or shielding issue in the guitar. But the owner insists it's elsewhere.   Any suggestions?
 
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.


john12ax7

Re: buzz buzz buzz....
« Reply #1 on: October 25, 2019, 03:34:30 PM »
Can you try the 335 with a different amp? It's possible the coil taps are not wired correctly for humbucking mode.  Or the guitar is not grounded / shielded properly. Either way the guitar being the source should be ruled  out first.

pucho812

Re: buzz buzz buzz....
« Reply #2 on: October 25, 2019, 04:22:38 PM »
Can you try the 335 with a different amp? It's possible the coil taps are not wired correctly for humbucking mode.  Or the guitar is not grounded / shielded properly. Either way the guitar being the source should be ruled  out first.

I agree. well the fractal is not an amp, sort of. It's a multi-FX box, official model name AXE-FX. This is the latest version. I have not ruled out the guitar but the owner insists it's not the guitar as it was recently gone over by a famous guitar tech and builder.  But that doesn't mean anything to me.  I can prove when buzz happens or not happens.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

Brian Roth

Re: buzz buzz buzz....
« Reply #3 on: October 25, 2019, 05:20:41 PM »
Well, try another guitar(s) into the setup to see what buzz problems it/they cause.

Bri
Brian Roth Technical Services
Salina Kansas, home of the best vinyl on the planet!

http://www.BrianRoth.com
recordingservicesandsupply.com/
www.qualityrecordpressings.com/
store.acousticsounds.com

pucho812

Re: buzz buzz buzz....
« Reply #4 on: October 25, 2019, 05:46:20 PM »
Well, try another guitar(s) into the setup to see what buzz problems it/they cause.

Bri

We did that and there was no buzz/ground issue related noises.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

PRR

Re: buzz buzz buzz....
« Reply #5 on: October 25, 2019, 06:06:18 PM »
Sent him to Guitar World to try every axe on the wall. If 98% are clean, and 2% buzz like his, there's a fault most guitars don't have and his does. (I'd expect some store guitars to have faults, so don't stop at the first buzzer.)

Brian Roth

Re: buzz buzz buzz....
« Reply #6 on: October 25, 2019, 06:47:40 PM »
We did that and there was no buzz/ground issue related noises.

Well, Troubleshooting 101 would point to the "magic guitar rebuilt by a guru" as the problem source.

Bri
Brian Roth Technical Services
Salina Kansas, home of the best vinyl on the planet!

http://www.BrianRoth.com
recordingservicesandsupply.com/
www.qualityrecordpressings.com/
store.acousticsounds.com

squarewave

Re: buzz buzz buzz....
« Reply #7 on: October 25, 2019, 07:51:18 PM »
If we use a different guitar,  say a takamine acoustic with internal pickup, there is no buzz.|
I am convinced there is a wiring issue or shielding issue in the guitar. But the owner insists it's elsewhere.   Any suggestions?
If by "internal pickup" you mean a piezo that's not going to pickup EMI as much as an "axe" with high output pickups. You need a comparable guitar like a Les Paul or 80's shredder.

Also when you say you tested the AXE-FX without anything plugged in, do you literally mean nothing in the jack? That would just terminate the input. Try unplugging the cable at the guitar end and maybe terminate it with a ~15K resistor somehow. If that's quiet, that points to the guitar.

Also, this might sound stupid but, try another cable. I had a cheap Fender cable that came with some guitar that was actually quiet compared the others I had.

alexc

Re: buzz buzz buzz....
« Reply #8 on: October 26, 2019, 12:45:48 AM »
In my humble experience, many  most  guitars have all kinds of hum and buzz, particularly the more elaborate winding-ed and wired ones      :(

I would go so far as to say that unless special attention is paid to    'super simple' and  'quality parts and wiring'    it's hard to get clean buzz free recording    ...   and   get  to  that     'promised land'  of quiet, expressive 'tone-vana'   [guitar recording wise]

          *and*    if at all humane-ly possible,     as heavy the shielding as possible   ..   installed

I mean adhesive copper foil tape liberally applied in every cavity   :)    Several layers with attention to making sure they all are grounded ...    as well as   fully braided and even foil internal shield  for the  signal wire etc   with mucho heavy guage copper wire  grounding ..  etc.    A full metal  'jack shell'  [a la vintage LPC s ]  is a plus too imho   8)

335s can be especially crappy challenging  ;D     For example! my own  '335 style'    is a re-worked gib 'Lucille'  1989 model  ..  a very average '335' in most respects at the best of times  ...   the best thing about it was the case  [lol], luxuriant, furry pink and with heavy duty tolex brown exterior  ..  it priced a lot more than it's worth,  out of the box ...   but at the time it was my first overseas posting with some deductable expenses to burn.

A  complete electrical re-works  [by me]  and a good luthier/finisher    [a friend] and some replacement gib parts turned   it into a proper 'stereo 345 recording beast'  and worthy of the gib legacy.

Until I mastered the basic 'dark art' of quiet elec-gtr wiring, I did my gib Lucille mods  with emg pups  - at least then it was completely silent.  One could say it was a bit lifeless with the actives, however  ...   Same for the gib lpc. Same for me, really.

After I got my 'thing' together  (20 years later), and with many more 're-wires' under my belt and with many more 'pickup types'  etc ,   I restored the elecs to original [on all my gits]    and this  'gib Lucille 345'  finally reached it's potential as the 'top of the heap'.

Just in time for an extended closet rest   :)

It's no dis-service to say that   it's the notes not played and not heard which can be the most   ephemeral and memorable.  Or not.

...

Same thing with my strat,  lpc,  rick bass, thinline tele, jazzmaster [a real well known hum-er] and so on.

The eyes still water when I hear my 'quiet' strat  - incredibly without  hum/hiss and such, and the 'strat' fidelity  - well it's to die for   ....  [dimarzio virtual vintage (passive) strat set with stock wiring].  I use it alot into a jensen DI box then onto my 'chain'.

It took years to find a proper heavy-duty '5 way selector' switch, but I did find a well-machined heavy duty and quiet one for the princely sum of around 17aud per. 

The stock fender '5 way selector' by comparison ..  sucked, flimsy with crap contacts prone to dirt and crackling ..  partial switch-overs all the time, both electrical *and* mechanical     .. phew a real stinker in every sense.

And the stock jack was always intermittant  ....   especially if   'played with'   ...  I did a proper us switchcraft replace,  and no probs again in that area.

..

Anyway - good luck with it all.   A 'quiet' elec guitar is a rare find in my experience!   [as is one that tunes up well and stays there]

Even with all the 'measures' in place, it still pays to 'play the git away from radiation sources'.   At least while recording.

Then, of course, there is another whole story (discourse) regarding 'mains power' and what not.

Lots of 'grist for the mill' there too.

My idea of heaven would be to have my own full time     guitar tech, luthier, diy audio builder, recording assistant and grounds-keeper - all in one - plus a faraday shielded battery powered studio.  :D  painted in yellow.
« Last Edit: October 26, 2019, 04:32:41 AM by alexc »
I ping therefore I am

Whoops

Re: buzz buzz buzz....
« Reply #9 on: October 28, 2019, 11:52:59 PM »
It's possible the coil taps are not wired correctly for humbucking mode.

I second that.
Maybe the Coils are not wired correctly for common mode rejection in humbucking mode.

Also, another thing to rule out is the possibility of  ground loop. There's 2 Powered speakers, it's a potential Ground loop situation.
Do the tests only with the output connected to one Powered speaker


abbey road d enfer

Re: buzz buzz buzz....
« Reply #10 on: October 29, 2019, 12:32:31 AM »

 Any suggestions?
Does hum change with the volume controls?
Who's right or wrong is irrelevant. What matters is what's right or wrong.
Star ground is for electricians.

clintrubber

Re: buzz buzz buzz....
« Reply #11 on: October 29, 2019, 02:04:46 PM »
Might have overlooked it, but was it already asked if/how the buzz changes when the position and/or distance w.r.t. the Fractal are varied?

FWIW, by design, there are some dual-PU instruments around that refuse to provide hum-cancelling when in both-PU-on mode (hello Rickenbacker).
The 335 not one of these, but possibly the guru-mod (or another PU-swap) brought in this feature...

> The guitar has coil taps and what is perplexing to me is that when in hum bucker setup with the pickups, there is buzz. making them single coil and the buzz level does not change at all.

Could these perhaps be switching the humbucker-halves from series to parallel (so actually not being coil-taps?)

pucho812

Re: buzz buzz buzz....
« Reply #12 on: October 29, 2019, 03:39:38 PM »
If by "internal pickup" you mean a piezo that's not going to pickup EMI as much as an "axe" with high output pickups. You need a comparable guitar like a Les Paul or 80's shredder.

Also when you say you tested the AXE-FX without anything plugged in, do you literally mean nothing in the jack? That would just terminate the input. Try unplugging the cable at the guitar end and maybe terminate it with a ~15K resistor somehow. If that's quiet, that points to the guitar.

Also, this might sound stupid but, try another cable. I had a cheap Fender cable that came with some guitar that was actually quiet compared the others I had.

Yes...  it does terminate input with nothing plugged in and the players Mogami instrument cable is noisy.  Some testing over the weekend  with a fender twin got us a cable that is quiet as a church mouse when connected to the fender twin. Going to try that same cable set up on this and see what we get.


I second that.
Maybe the Coils are not wired correctly for common mode rejection in humbucking mode.

Also, another thing to rule out is the possibility of  ground loop. There's 2 Powered speakers, it's a potential Ground loop situation.
Do the tests only with the output connected to one Powered speaker

Tased with a single powered speaker and hums just as much.  I can't see a ground loop happening with the axe-fx and two powered monitors. they are on the same circuit and connected with nice xls cables.



Does hum change with the volume controls?

I can't recall off hand. In a perfect world it would.  Need to test again when I go visit.

Might have overlooked it, but was it already asked if/how the buzz changes when the position and/or distance w.r.t. the Fractal are varied?

FWIW, by design, there are some dual-PU instruments around that refuse to provide hum-cancelling when in both-PU-on mode (hello Rickenbacker).
The 335 not one of these, but possibly the guru-mod (or another PU-swap) brought in this feature...

> The guitar has coil taps and what is perplexing to me is that when in hum bucker setup with the pickups, there is buzz. making them single coil and the buzz level does not change at all.

Could these perhaps be switching the humbucker-halves from series to parallel (so actually not being coil-taps?)

Yes it could easily be that as opposed to coil taps.  But that is what the owner said, so that is what I repeated.   The one thing I have not had my hand on is the guitar itself.  I assume it's as s simple as the more you add to the plumbing the easier it is to stop up the drain.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.


 

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