VXT preamp woes
Bill C
Posted 2022-06-17 11:49 PM (#557396)
Subject: VXT preamp woes


Joined:
December 2004
Posts: 62

Location: Phoenix
Bought this VXT new from Alpep back about 15 years ago and gigged with it for five years or so, then life happened and it didn’t get used in a long time. Dug it out, put new battery in it, and I don’t have any output to the “ring” (acoustic) output whether in mono or stereo. I do have continuity from the cable through the jack back to the preamp board, so it’s not a cable or jack issue, and I have tried multiple fresh batteries. I do have acoustic sound to the “tip” when the blend pot is dialed to acoustic (however the tip always has a magnetic pickup signal, even when the switch is set to Stereo and the pot is dialed to pure acoustic). I also have checked the stereo/mono switch signal back to the board and the switch is working properly. This tells me that there is likely a switching transistor or Opamp on the preamp board that has gone kaput. So…is there any way on God’s green earth to get a replacement preamp board? Or maybe the schematics for this preamp? Though I hate working on SMD boards…

Otherwise I will lose the main feature of this guitar, the ability to split the acoustic and electrical guitar signals to send the former to the mixing board and the latter to a guitar amp.

Edited by Bill C 2022-06-17 11:59 PM
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Bill C
Posted 2022-06-18 8:10 AM (#557397 - in reply to #557396)
Subject: Re: VXT preamp woes


Joined:
December 2004
Posts: 62

Location: Phoenix
…..Okay, fantastic news. Turned out it was actually the mono/stereo switch itself, and solved by a liberal application of Deoxit to the switch. My initial assessment (that the switch was operating properly) had been done on the kitchen table with my multimeter rather hastily and when I put the guitar on my workbench properly, I diagnosed that the switch was not closing the circuit between the yellow and white wires. So not anything on the preamp board itself, thank goodness! Guitar now ready to use, functional in stereo mode.
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MWoody
Posted 2022-06-18 9:03 AM (#557398 - in reply to #557396)
Subject: Re: VXT preamp woes



Joined:
December 2003
Posts: 13987

Location: Upper Left USA
I love a happy ending! Now to go and find another VXT... it's been a while.
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