Alembic Guitars Club

Alembic products => Owning an Alembic => Troubleshooting => Topic started by: gtrguy on January 19, 2024, 02:21:28 PM

Title: Epic 'Motorboats'
Post by: gtrguy on January 19, 2024, 02:21:28 PM

Epic Motorboats


I have an Alembic Epic that quietly 'motorboats' and was wondering if anyone here might have any idea why? It is not very noticeable but it's there.

Title: Re: Epic 'Motorboats'
Post by: edwardofhuncote on January 19, 2024, 03:30:22 PM

Cellular noise?

Title: Re: Epic 'Motorboats'
Post by: gtrguy on January 20, 2024, 10:21:21 AM

No, none of my other electronics does it.

Title: Re: Epic 'Motorboats'
Post by: JimmyJ on January 20, 2024, 10:47:35 AM

Hey David,

That's an odd issue and I don't understand the circuit enough to know what might cause that kind of oscillation.  It could be a failing component; opamp, voltage regulator (if there is one), a failing capacitor... but of course is should not be happening.  You already know about exercising pots and switches so try that first and let us know if that has any effect.

The noise that Greg was suggesting is the RF spew that cell phones blurt out when trying to connect to the closest tower.  It's a wild sound that is easily picked up by any nearby guitar pickup but it usually only happens for a few seconds so probably not what you are describing.

Jimmy J

Title: Re: Epic 'Motorboats'
Post by: fmm on January 22, 2024, 05:24:28 AM

This may not be the case, but back when I was installing car and boat stereos this was caused by ground issues.

Title: Re: Epic 'Motorboats'
Post by: mica on January 22, 2024, 02:06:08 PM

Has this just started happening? Never had any report of motorboating, and faintly makes it even more of a weird thing. First thought is a failing capacitor. Will have to think about it some.

Title: Re: Epic 'Motorboats'
Post by: mica on January 22, 2024, 02:14:54 PM

Also, does the sound happen all the time? Under only certain tone settings or all? How loud is it compared to the output of the signal?

Title: Re: Epic 'Motorboats'
Post by: gtrguy on January 22, 2024, 04:19:11 PM

It's been there as long as I have had the bass (3 - 4 years) and putts away quietly in the background all the time. My 4 string using the same signal path is quiet.

Title: Re: Epic 'Motorboats'
Post by: mica on January 22, 2024, 11:45:08 PM

It sounds like something we would have to test out to determine the cause and repair.