Quick question about the thunderhead balance control
Kev100
Posted 2021-02-21 5:39 AM (#555188)
Subject: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Hi,
The balance control on my 72 thunderhead sweeps between the neck pickup, through to the bridge pickup. However, the middle part has much lower output than either end. It’s always been like this since I got the guitar, and I’ve never given it much thought, apart for needing a clean with some switch cleaner to get rid of some noise. Now it just struck me as counter intuitive. I’d have thought that the middle position of the control should have both pickups on, and deliver more output?
Do I need a replacement pot?
Cheers,
Kev
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alpep
Posted 2021-02-21 12:50 PM (#555191 - in reply to #555188)
Subject: Re: Quick question about the thunderhead balance control


Joined:
December 2001
Posts: 10581

Location: NJ
try cleaning the controls
is the neck pickups louder than the bridge?
is it just the perception of sound?
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Kev100
Posted 2021-02-21 1:38 PM (#555192 - in reply to #555191)
Subject: Re: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Hi, thanks for the suggestion. I’d say that both pickups have equal volume, but with the balance pot in the mid position the volume drops to about half ... it’s really unusable.
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Kev100
Posted 2021-02-21 2:02 PM (#555193 - in reply to #555192)
Subject: Re: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Hi again, just found an online manual, which says that in the middle position, ‘both pickups are heard equally’ ...

http://www.ovationtribute.com/Catalogues/60%27s_Ovation_Thunderhead...

On mine there’s definitely a drop in volume towards the middle position.

I guess the only way to be sure is to take the pot out and maybe find a replacement.

Kev
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Mr. Ovation
Posted 2021-02-21 2:16 PM (#555194 - in reply to #555188)
Subject: Re: Quick question about the thunderhead balance control


Joined:
December 2001
Posts: 7209

Location: The Great Pacific Northwest
The three-way switch is "in-phase, out-phase, and mute. Is it working correctly? Those (if original) are single-coil pickups so there really shouldn't be a huge drop in the middle, but I'm thinking if that switch is messed up, or been re-wired that might cause an issue. Anyway, check it out.

If that's not the issue, I would pull the pickups and you can usually get tuner-cleaner to the pots via a thin straw from the pickup opening. Make sure all wires are secure.
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Kev100
Posted 2021-02-21 2:57 PM (#555195 - in reply to #555194)
Subject: Re: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Thanks for the suggestion. The switch works as it should, but to be fair, it and the pots could all do with a clean.
I’ll check it out.
If it comes to it, though, any idea where I can get a replacement pot?
Kev
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Mr. Ovation
Posted 2021-02-21 7:03 PM (#555196 - in reply to #555188)
Subject: Re: Quick question about the thunderhead balance control


Joined:
December 2001
Posts: 7209

Location: The Great Pacific Northwest
The pots are pretty standard as I recall. I have a couple of complete looms I think... the thing is... "dirt" doesn't generally cause what you describe which is more faulty connection sounding.
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Kev100
Posted 2021-02-22 2:10 AM (#555198 - in reply to #555188)
Subject: Re: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Thanks everyone, good to know that my guitar isn’t as it should be. I’ll investigate further. I don’t suppose anyone’s got a wiring diagram for the thunderhead?
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Old Man Arthur
Posted 2021-02-22 2:25 AM (#555200 - in reply to #555198)
Subject: Re: Quick question about the thunderhead balance control



Joined:
September 2006
Posts: 10777

Location: Keepin' It Weird in Portland, OR
Kev100 - 2021-02-22 12:10 AM

Thanks everyone, good to know that my guitar isn’t as it should be. I’ll investigate further. I don’t suppose anyone’s got a wiring diagram for the thunderhead?


http://www.ovationtribute.com/Ovation%20Schematics/Ovation_Thunderh...



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Kev100
Posted 2021-02-22 2:53 AM (#555201 - in reply to #555188)
Subject: Re: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Thanks literally just found that myself (what a wonder Google is)
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Kev100
Posted 2021-02-22 9:42 AM (#555203 - in reply to #555188)
Subject: Re: Quick question about the thunderhead balance control


Joined:
October 2019
Posts: 21

Okay, sit rep time. I spent a fair chunk of the morning disassembling the guitar, checked all soldered joints (amazingly all okay) and switch cleaning the pots and selector switch. Got it all back together again (fairly easily) and put new strings on. No crackles and drop outs when using the pots, and the switch is perfect. However, there's still a dip in volume mid way through the balance put sweep. I downloaded a decibel meter app onto my phone and repeatedly plucked the G string whilst sweeping the balance from neck to bridge. With the particular volume setting I was using, there was a drop of around 10dB at the mid point (in both in-phase and out of phase). In the region of 68 - 58-68 dB.
Can someone with one of these guitars try this experiment and let me know if my (admittedly non-scientific) results are typical and normal for the Thunderhead, in which case I can stop chasing ghosts, or maybe I do in fact have an issue. I used Sound Meter on Android, but I guess the effect, if present, should show on any app/device.
Cheers,
Kev
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