The Acoustic Guitar Forum

Go Back   The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Reply
 
Thread Tools
  #1  
Old 12-09-2019, 04:22 PM
AxeDude AxeDude is offline
Registered User
 
Join Date: Jul 2015
Location: Black Hills of SD
Posts: 143
Default Unusable Martin JC40

My main guitar that I’ve been playing gigs with for the last 25 years is now useless. The preamp has developed an occasional short. I’ve called Martin and they claim they have no information about the electronics and that they can’t help me. The electronics say made in England, and it’s an 18v system. It has worked really nicely with my ToneDexter. The guitar has TWO big holes for the system. One on the top rim and another below the end pin. I have four Martins and I have to comment that I am really disappointed in their lack of concern regarding this issue.
Reply With Quote
  #2  
Old 12-09-2019, 04:43 PM
jonfields45 jonfields45 is offline
Registered User
 
Join Date: Jun 2011
Location: Allentown, PA
Posts: 4,598
Default

Maybe a few pictures would be helpful.
__________________
jf45ir Free DIY Acoustic Guitar IR Generator
.wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below
I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs
IR Demo, read the description too: https://youtu.be/SELEE4yugjE
My duo's website and my email... [email protected]

Jon Fields
Reply With Quote
  #3  
Old 12-09-2019, 05:40 PM
AxeDude AxeDude is offline
Registered User
 
Join Date: Jul 2015
Location: Black Hills of SD
Posts: 143
Default

I’ll try to put some pics on tomorrow. I have a hard time believing Martin has no information about the electronics that they installed from the factory.
Reply With Quote
  #4  
Old 12-09-2019, 07:28 PM
Br1ck Br1ck is offline
Charter Member
 
Join Date: Sep 2014
Location: San Jose, Ca
Posts: 6,943
Default

You bought the guitar new? I can't remember any Martin made in GB systems, but what do I know?
__________________
2007 Martin D 35 Custom
1970 Guild D 35
1965 Epiphone Texan
2011 Santa Cruz D P/W
Pono OP 30 D parlor
Pono OP12-30
Pono MT uke
Goldtone Paul Beard squareneck resophonic
Fluke tenor ukulele
Boatload of home rolled telecasters

"Shut up and play ur guitar" Frank Zappa
Reply With Quote
  #5  
Old 12-09-2019, 08:08 PM
AxeDude AxeDude is offline
Registered User
 
Join Date: Jul 2015
Location: Black Hills of SD
Posts: 143
Default

Here’s a couple pictures IMG_0052.jpgIMG_0053.jpg
Reply With Quote
  #6  
Old 12-09-2019, 08:14 PM
Guest 33123
Guest
 
Posts: n/a
Default

I found this:

https://reverb.com/item/5190410-mart...p-1980-s-black

https://www.acousticguitarforum.com/...d.php?t=427139

So effectively zilch. Sorry.

Last edited by Guest 33123; 12-09-2019 at 08:25 PM.
Reply With Quote
  #7  
Old 12-09-2019, 08:24 PM
AxeDude AxeDude is offline
Registered User
 
Join Date: Jul 2015
Location: Black Hills of SD
Posts: 143
Default

Quote:
Originally Posted by J-Doug View Post


Wow, thanks for checking this out! Martin must have been using this for quite some time. I had my local dealer order this for me in 1994.

I’ve taken the “guts” out, but can’t see any cold solder spot or loose wire. It is like a bad cord would act.
Reply With Quote
  #8  
Old 12-09-2019, 08:26 PM
BlueStarfish BlueStarfish is offline
Registered User
 
Join Date: Sep 2019
Posts: 377
Default

That's a bummer, sorry to hear about it.

I think the 18v spec is unusual. Most of the systems I see in the market currently have a 9v spec. The only one I'm aware of with an 18v spec is the Seymour Duncan wavelength (formerly DTAR) UST system. I don't see an onboard / barn door version of that on the market currently but maybe they had one at one point? Just a guess. The Wavelength UST seems to be well regarded so if that's it, not surprised you liked it. You might try partly removing the preamp module and see if there is a manufacturer label; Martin was almost certainly not the manufacturer.

What to do? You could try to replace the system with another onboard system. Maybe a good guitar tech could re-use the battery compartment / endpin jack and re-solder that to a new replacement onboard system. Fishman and Baggs both have retail packages for onboard preamps / pickups that you could install.

This situation is a good example of why it's best to avoid buying a guitar with a barn door style system. I have a couple of guitars that have them (both of which I bought used a few years ago, so not too much money invested). But more recently have avoided the barn door systems and plan to continue doing so. Hope you can sort this out.
Reply With Quote
  #9  
Old 12-09-2019, 08:51 PM
RRuskin RRuskin is offline
Registered User
 
Join Date: May 2006
Location: Seattle WA
Posts: 2,619
Default

It could be as simple as a shorted or broken contact. Have someone that knows guitar electronics take a look at it.
__________________
Rick Ruskin
Lion Dog Music - Seattle WA
Reply With Quote
  #10  
Old 12-09-2019, 09:03 PM
Guest 33123
Guest
 
Posts: n/a
Default

Quote:
Originally Posted by AxeDude View Post
Wow, thanks for checking this out! Martin must have been using this for quite some time. I had my local dealer order this for me in 1994.

I’ve taken the “guts” out, but can’t see any cold solder spot or loose wire. It is like a bad cord would act.
No problem. Outside of those two links I posted I found nothing on the interwebs. I hit the reference books too but couldn't find any leads. As Rick says take it to an electronics repair shop. Might be fixable...
Reply With Quote
  #11  
Old 12-10-2019, 06:17 AM
Cuki79 Cuki79 is offline
Registered User
 
Join Date: Feb 2012
Location: France
Posts: 3,005
Default

Circuits were discrete in the 80s right?

It should be possible to fix it by a professional electronic engineer
__________________
Martin 00-18V Goldplus + internal mic (2003)
Martin OM-28V + HFN + internal mic (1999)
Eastman E6OM (2019) Trance Audio Amulet
Yamaha FGX-412 (1998)

Gibson Les Paul Standard 1958 Reissue (2013)
Fender Stratocaster American Vintage 1954 (2014)
http://acousticir.free.fr/
Reply With Quote
  #12  
Old 12-10-2019, 06:42 AM
jonfields45 jonfields45 is offline
Registered User
 
Join Date: Jun 2011
Location: Allentown, PA
Posts: 4,598
Default

I used opamps in college in the 70s, but it is not going to be surface mount and it should be repairable. Probably a cracked solder joint or a bad capacitor.
__________________
jf45ir Free DIY Acoustic Guitar IR Generator
.wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below
I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs
IR Demo, read the description too: https://youtu.be/SELEE4yugjE
My duo's website and my email... [email protected]

Jon Fields
Reply With Quote
  #13  
Old 12-10-2019, 10:19 AM
AxeDude AxeDude is offline
Registered User
 
Join Date: Jul 2015
Location: Black Hills of SD
Posts: 143
Default Unusable Martin JC40

Thanks for your replies. I’m hoping a electronics engineer will fix this. I was happy with this guitar and a Fishman Aura DI, but with a ToneDexter my search for great tone was over.
-Very frustrating in that it’s such an intermittent problem. I can’t trust it for a gig.

Last edited by AxeDude; 12-10-2019 at 10:26 AM.
Reply With Quote
  #14  
Old 02-02-2020, 04:04 PM
AxeDude AxeDude is offline
Registered User
 
Join Date: Jul 2015
Location: Black Hills of SD
Posts: 143
Default

Problem fixed! Nothing wrong with the electronics in general. There was a slight open circuit being caused by one of the 9v battery plugs. I soldered better snap on connectors to the circuit board and everything is fine once again.
Reply With Quote
Reply

  The Acoustic Guitar Forum > General Acoustic Guitar and Amplification Discussion > Acoustic Amplification

Thread Tools





All times are GMT -6. The time now is 11:17 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright ©2000 - 2022, The Acoustic Guitar Forum
vB Ad Management by =RedTyger=