Want to build a Thunderbird!

SFIV1967

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airplane

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This would have been also my first question. @airplane: Have you verified with a multimeter (ohmmeter) that there is a connection between the strings and the ground of the guitar connector socket?

Also this is maybe useful, check that you have no ground loops inside! https://www.fralinpickups.com/2018/11/12/understanding-guitar-grounding/

Ralf

well yes the ground is connected to the bridge so i guess the strings are connected too but i don’t have such a devoce to check.

and ground loop is possible! i think i soldered a loop between all four pots (just to be sure :witless: oops). could that result in weird effects like that?
 

GAD

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A ground loop is the means where by there is a difference in potential between two ground points thus causing current to flow. Grounds should always be designed in a star configuration and never in loops, so that is something to fix on the guitar.

Does the problem continue to exists if without your left hand touching the strings?

Guitar looks great by the way!
 

Nuuska

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Hello

Ground loop typically generates hum - 50Hz in Europe - 60Hz in USA and some other places . . .
But because the mechanism of ground loop is that two points are connected via two or more routes, there is a loop - and the omnipresent electric field emanating from electric motors, transformes, light fixtures, house wiring etc. goes through that loop and generates electricity, that becomes audible, if circuitry is high impedance enough.

The ground loop within your guitar is
small - so nothing to worry about - it would only produce minuscule hum - if any.

Large ground loops are typically coming up when you i.e. have pa-system with snake to f.o.h to mixer - and you provide electricity from more than one single grounded source. Like you bring your mixer across the room and notice, that there is wall outlet. Plug in and HUM! Reason being, that who knows which way the cable goes inside building, before it reaches the outlet - it can well be, that it comes from altogether different source than the outlets at stage. So the loop length might be hundreds of meters - thus providing plenty of area for that electric field to penetrate.Only way to be sure is to pull power cable next to snake to F.O.H. and use that.


But - back to your guitar - you could invest few Euros and buy a multimeter - it is very useful for checking cables, speakers etc - a 10€ unit will do. With that you can measure pickup dc-resistance, too.

Meanwhile - plug your guitar into amp, turn the amp on and volume up to comfortable level. Do not touch any metal parts - can you hear light hum/buzz from amp? Does it go away when you touch various parts of the guitar? Including strings? If yes, then you have the strings grounded.
 

SFIV1967

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i think i soldered a loop between all four pots (just to be sure :witless: oops). could that result in weird effects like that?
Nuuska is right that such loop is small but you could easily open that loop (cut the one ground wire at the pots) and check if it gets better.
Ralf
 

adorshki

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The Theramin idea is an interesting one but gets into things like stray capacitance which I'm going to put on hold for now.

Or have you perhaps been handling too much gold with bare hands - and your palm pores are filled with gold particles - this would affect magnetic field of pickup . . .

Seriously - proximity of hand varies capacitance of the system - and guitar being more inductive with low-mid impedance is normally not that sensitive for capacity.

I feel so vindicated!
:glee:
Also owe Nuuska an apology for forgetting that he is also quite well versed in these issues from his professional career as a sound tech/recording engineer.
I really think you need to try to see what happens when you play without the rings, (recall that was one of my initial questions< something on your wrist?) and after confirming proper grounding, verify capacitor/resistance values.
PS Good multi-meters are pretty darn cheap these days.
Shielding around circuitry is to protect from RF interference, even fluorescent lights can create annoying hums.
 

airplane

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hi there. i'm in vienna now but i will try it without the rings when i go to a guitar store to kill some time :witless: @GAD touching the strings with the left hand or not makes no difference...

so.. while i'm uploading some thunderbirds pics i thought i throw a little NGD spam in here. i got myself a 360/12c63 for my 30th birthday about a month ago :abnormal:
46790407752_4b1191ee5e_b.jpg
 

airplane

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so here it is. it turned out pretty damn good for my first build! pretty happy with the looks and how it plays.

46790524012_64262d8bae_b.jpg


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original size: https://c2.staticflickr.com/8/7850/46790511692_9834042f04_o.jpg

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https://c2.staticflickr.com/8/7804/32967026908_1bd993a411_o.jpg

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the lightly aged mojo turned out just as i was hoping. i was very very careful with the "thermo-aging" process (don't hate, it does affect the resonance very much) and the dings and scratches are more or less real, i just didn't work carefully with the tools when i was assembling it and setting it up.

family portrait (say "guuuiiiiiilllld"):
32967029188_74b2c87c78_b.jpg
 

GAD

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You did a killer job on that guitar.

What's up with the bridge angle and the holes in front of the bridge?
 

matsickma

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Outrageous!
One recommendation. Pick up a extra Hagstrum bridge saddle. Take a file, dremmel tool or sandpaper and take down the sharp knief edge on the outside corner of the saddle. This will save you much pain and occasional bleeding if your Thunderbird becomes your main Axe! Keep the unmodified saddle around for taking pictures of your baby.
M
 
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