Alembic Guitars Club

Alembic products => Alembic Basses & Guitars => Topic started by: 87_persuader on March 17, 2013, 12:56:45 PM

Title: Series 1 preamp noise
Post by: 87_persuader on March 17, 2013, 12:56:45 PM
I think i want to send my 1976 Series 1 preamp in for testing...power supply ripple tested OK...so noise is prob in preamp. How do i go about doing a return?
 
Jim
Title: Series 1 preamp noise
Post by: slawie on March 17, 2013, 06:29:02 PM
Have you gone through the procedure as outlined here?
http://club.alembic.com/Images/16271/16309.html?1208918154 (http://club.alembic.com/index.php?topic=269)
slawie
Title: Series 1 preamp noise
Post by: 87_persuader on March 18, 2013, 05:26:57 AM
The problem is alittle different; neck pickup doesn't work,bridge does...if i swap red and blue wires from preamp i get neck but no bridge. Lotta 'egg frying' noise like a bad cap sound..the square gold colored transistor on the board gets pretty warm....neck PU vol pot seems bad during sweep and the tone pot on bridge PU had broken in half...taped together...so i have a few issues to resolve.
Title: Series 1 preamp noise
Post by: JimmyJ on March 18, 2013, 09:22:21 AM
Sounds like it needs some help!  We're all Alembic nuts in here so we'd love to see a pic and hear more about the instrument if possible.
 
The square gold component you describe could be the original flat pack op-amp (many pins soldered to the board).  I think there were 3 of these back in the day, on the underside of the board?  These can run hot when operating correctly and if two are hot and one isn't then the cold one might be dead.  (I'm just making this up so wait until somebody who actually knows can confirm my theory.)
 
Your best bet of course would be to get the instrument to the factory for a once-over.  Beyond that, they can supply you with parts, including a new preamp board and adaptors, and help you work on it.  Either approach will take time, patients, and some dough... but we cheer your efforts to revive the old axe!
 
Tell us more!
 
Jimmy J
Title: Series 1 preamp noise
Post by: gtrguy on March 18, 2013, 10:18:05 AM
If I remember right, they have a set price to repair that board and it is quite reasonable.
 
If you have narrowed it down to the board, I would email Mica at Alembic.