Alembic Guitars Club

Alembic products => Owning an Alembic => Troubleshooting => Topic started by: ajdover on July 22, 2022, 01:43:45 PM

Title: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on July 22, 2022, 01:43:45 PM
Folks - I just received a ‘95 Essence via trade, and it has terrible R/F interference when the pan pot is rotated all the way back to use the bridge pickup only.  I can literally hear a radio station broadcasting.  The weird thing is that it occurs when I have it completely back - if I move it slightly back (and I mean slightly), the R/F interference pretty much goes away (I can still hear it faintly).  I had this issue with my ‘91 Essence, but it’s been a while and I don’t remember what we did to fix it.  Any suggestions?


Alan
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on July 23, 2022, 03:32:12 PM
Update - I took the Essence to my local Guitar Center (yes, Guitar Center) so see if maybe it was a location thing.  Rotated the pan pot to the bridge pickup, and no noise whatsoever.  Maybe is a location thing?
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: edwardofhuncote on July 23, 2022, 05:37:44 PM
You might try looping the pickup leads through a ferrite bead, if they aren't already.

*link- https://club.alembic.com/index.php?topic=219.msg1026#msg1026
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: mica on July 25, 2022, 01:16:16 PM
You should already have the ferrite shielding bead on the pickup leads. I will send you one to try and put on the lead from the pan pot to the rest of the circuit.

It's likely the issue will be resolved by switching to the new Pan Preamp board, but you can try this out first and that will be helpful to know if it works for other people with older Essence basses.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on July 25, 2022, 04:22:36 PM
Mica,


      I’ll give that a shot and let you know how it goes.  Thanks for the help!


Alan
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: keith_h on July 26, 2022, 08:07:48 AM
Alan, Good to see you around. Hope things are going well.

I had that problem with my fretless Orion. It was a lower power station south to south east of me and could only be picked up over a few degrees of turning. Though once found the reception was great. :) Unless you are right on top of the transmitter radio station interference tends to be location and frequently direction specific. In my case replacing the preamp board fixed it.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on July 26, 2022, 05:08:14 PM
Keith - great to hear from you, and I hope all is going well!


Mica’s going to send me a ferrite bead, and I’ll try that.  If that doesn’t work, then I’ll go the route you did.


Alan
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on July 28, 2022, 06:22:03 PM
Update - an Alembic Club member contacted me after seeing my post about RF interference.  He had a pan pot preamp that he’d purchased to use on an Essence, but ended up not doing so.  He very graciously offered it to me.  I asked him how much he wanted for it, and he said basically not to worry about it, and that he’d be sending it to me, gratis.  I will use it on the ‘95 Essence and see how it goes, along with having a 3-way Q switch installed.


This, my friends is what makes Alembic owners so special in the nearly 20 years I’ve been playing them.  It’s also a reason I will always be an Alembic player.


Alan


P.S.  Anyone have a link to the instructions for installing the pan pot pre and the 3-way switch?  I need to give them to my tech for installation.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: lbpesq on July 28, 2022, 06:24:27 PM
I LOVE THIS PLACE!!

Bill, tgo
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: adriaan on July 29, 2022, 04:27:00 AM
The pan preamp comes with printed instructions.For me it was all plug-and-play, although not everything was immediately evident to my muso brain.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: keith_h on July 29, 2022, 08:34:03 AM
That's great to hear.

To install the Q switch your tech might have to remove some wood to allow the threads to go through the front (I did on my Orion). They should repaint the area with shielding paint after removing the wood.


The Q switch is easy to connect. I recall soldering one or two connections but it has been a very long time since I installed one. I'll look around to see if I still have the instructions and email you a copy if I do.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: rv_bass on July 29, 2022, 05:33:15 PM
Here is a link to a PDF of the Q switch installation instructions

http://alembic.com/club/messages/393/025-001-13735.pdf
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: pauldo on July 30, 2022, 03:35:22 PM
I LOVE THIS PLACE!!

Bill, tgo

Same
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on July 30, 2022, 03:59:47 PM
Is this the same for a 3-way switch?
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: rv_bass on July 30, 2022, 04:51:43 PM
Is this the same for a 3-way switch?

I believe so. 
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: keith_h on August 01, 2022, 08:18:25 AM
Rob's post point to what I remember doing when I installed my 2-way Q switch. Not sure if it would be the same for a 3-way as I've never seen one for an Activator circuit.

Thanks Rob now I don't have to search through my lost papers drawer where things like this always end up.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on August 06, 2022, 04:20:38 PM
So, my tech has the bass.  He’ll install the pan pot board and the three way switch, but it doesn’t need the ferrite bead - we found one in there when he opened it up.  Once I get it back, I’ll post with pics and an update.  Thanks to everyone for all the help!
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: mica on August 06, 2022, 08:36:24 PM
There's one on the pickup leads. The suggestion was to _add_ one between the pan pot and the rest of the electronics. But do try the pan preamp first. Make sure you turn down the gain on the filter control to zero, since you'll be using the two new preamps on the pan control.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on August 31, 2022, 03:57:12 PM
I’ll be getting the bass back tomorrow.  I’ll post here to let everyone know how it goes.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on September 02, 2022, 02:40:18 PM
OK, so I got the bass back today.  Played it at my tech’s place, all was good.  Got it home, and the RF interference is gone.  However, I’m hearing a crackling sound from the amp.  I worked the jacks on the amp and the bass, and rotated all the knobs too.  I’m wondering if it is the amp?  I’ll be playing around with it in the next few days.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: rv_bass on September 02, 2022, 03:06:18 PM
Do you have another amp at home you can test it on?  Also, maybe try plugging headphones into the 1/4” jack on the bass and see how it sounds.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on September 02, 2022, 03:59:18 PM
Just plugged it into my Phil Jones Bass Cub.  Same issue.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: rv_bass on September 03, 2022, 02:58:35 PM
Just curious, have you plugged your amps into a different wall socket and/or power strip? Maybe that’s the source  since it didn’t happen at your tech’s shop.
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: pauldo on September 03, 2022, 05:37:04 PM
Did you try different instrument cable(s)?
Title: Re: RF Interference When Using Pan Pot - 95 Essence
Post by: ajdover on September 04, 2022, 02:08:34 PM
Just curious, have you plugged your amps into a different wall socket and/or power strip? Maybe that’s the source  since it didn’t happen at your tech’s shop.

Yes.  It’s not the outlet.