Aggie Pre getting radio station signal

[ubado]

I just wired up a Aggie OBP-3 preamp... now I'm getting radio signals.

Besides the use of shielding (currently it doesn't have any), is there any way to wire it so that I don't get the radio signals.

It just happens when I touch the "treble" & "mid" knobs also the mid selector switch, ... not on the "bass" and not on the volume pots either (well that I can hear). When I touch the treble, mid and switch... the station comes in loud and clear.

BTW... the station sucks... too much chat.

I'm gonna try another cable to see it that's it too.

[Chad Michael]

Went to purchase a second hand amp / cabinet and the seller had us meet at his church to demo the rig. I could hear a radio station thru the amp (faint, but definitely there).

Looked outside, there was a radio broadcast antenna less than 1/8 mile away .

[ubado]

Originally Posted by ubado

I just wired up a Aggie OBP-3 preamp... now I'm getting radio signals.

Besides the use of shielding (currently it doesn't have any), is there any way to wire it so that I don't get the radio signals.

It just happens when I touch the "treble" & "mid" knobs also the mid selector switch, ... not on the "bass" and not on the volume pots either (well that I can hear). When I touch the treble, mid and switch... the station comes in loud and clear.

BTW... the station sucks... too much chat.

I'm gonna try another cable to see it that's it too.

It's the preamp itself!

I strung wire to each of the preamp pots and the switch... then connected it to one of the volume pots and the ground on the input jack. Now I doesn't pick them up then I touch the knobs.

However, the preamp wires still do when they touch anything.

If you have any input... please feel free to chime in.

[luknfur]

If the bridge isn't grounded I'd try that first - some guys think anything with a pre or active pups don't need the bridge grounded (which they - or any bass - doesn't if they work fine otherwise).

Shielding would likely be a next best bet. If done properly, it won't hurt anything and may do the trick.

Another thing I'd do is try a different bass/guitar, move the amp around, use a different receptacle, turn off all other electric components in the room - act like you're stuff's possessed in other words. Lot of latter voodoo around. Every link in the chain matters and it may not be the bass at all or it may just be the environment. Regardless it's free and easy.

Always go for the easiest, quickest, cheapest, least invasive approach first - may save a lot of time, money, and grief not to mention actually resolve the problem.

[ubado]

Originally Posted by luknfur

If the bridge isn't grounded I'd try that first - some guys think anything with a pre or active pups don't need the bridge grounded (which they - or any bass - doesn't if they work fine otherwise).

Yea, the bridge isn't grounded... it's got EMG's... I've never seen them grounded in all my years of owning basses with them (I've owned more EMG's than any other brand).... But what the heck... it's worth a shot... couldn't hurt either.

Grounding all the pots worked well... no more talk radio when I touch them. Now it's only when I touch the preamp wires. I've moved the Aggie to another spot in the cavity... isn't as much of a problem now. However I'm still gonna shield the cavity as well.

Thanks for the tips

[luknfur]

I wouldn't expect moving the pre to do anything but you never know till you try.

I'm not opposed to shielding when required but it's not a fun project and you're as likely to create problems as resolve them in doing so. If it only does it when you touch the preamp wires then there should be no problem since the only way to touch the wires is to have the control bay cover off which is not going to happen under any playing conditions.