Radio stations coming in...:-(

[pblack99]

Hi Folks,

I have a 2000 SC Standard that seems to pickup radio stations when I combine my front and back pickups but not when I am using only one or the other pickups. At I thought about the grounding in the active electronics area but then, because it only happens when I am in Combine mode, I wonder if maybe it could be the switch. Anyone else had this issue? And I need to be upfront, I am skilled at a few things but electronics is not one of them.

Phil Black

[jazzyvee]

Does the bass still have the pickup wires going through the ferrite bead in the control cavity?

[edwardofhuncote]

I had this happen one time on a set of Alembic Activators for a Telecaster. I heard a Spanish-language radio station through them. It was all on me though.


Problem at Post #67, Solution at Post #74. https://club.alembic.com/index.php?topic=25796.60


Hope this helps you. 

[pblack99]

Jazzyvee - yes. The pickup wires are going through the ferrite bead in the control cavity.

[pblack99]

Edwardofhuncote - This has just started perhaps a few months ago.

[garyhead]

Could maybe a new cell phone tower gone up in the past few months?  Your SC is now 25 years old.  Lots of new RF Interference since then.  If nothing obvious in the control cavity maybe an RF Upgrade might be needed.  My 96 Classico picked up tv stations.  Alembic did an RF upgrade in 2019.

[mica]

Signature model wouldn't usually have a pickup selector switch. Can you post an image of the electronics cavity?

We have an RF upgrade available for all of the HF noise sources that have evolved in the last 25 years since your bass was born. Even radio stations that weren't a problem then are now as many have been pushed down lower on broadcasting towers by digital television.

You can email me (mica@alembic.com) and we can get you the parts you need. I'm glad to report this is now a fairly easy to do mod in field. We have you replace the 2 8-pin ICs with 2 small circuit boards that has the ICs and the filtering circuit. The ICs are socketed in the original circuit, so there is no soldering.

[pblack99]

Mica - sent you the email with pics. Thanks! Phil Black

[sonicus]

When I first auditioned, my 73-32 Series 1, It was at SOUND WAVE STUDIOS in Emeryville. It is a rehearsal studio in proximity to the Emeryville "Mudflats"  where there are several RF transmission towers along with their respective transmitters. That location in my experience has a serious issue with RFI noise, and the Alembic 73-32 was definitely picking up multiple RF signals there. However, I purchased the bass that day and was elated to have done so. When I got home, I immediately hooked it up to play it, and it was SILENT except for the notes that I played on it ! That was a true GILLIGAN ; "Like WOW, man ! " Moment.
I am seriously grateful to Alembic to have also perfected it even more since my purchase.