Bare Knuckle Pickups Forum

Forum Ringside => Pickups => Topic started by: witeter on December 31, 2013, 11:29:13 AM

Title: Blackhawk feedback issue
Post by: witeter on December 31, 2013, 11:29:13 AM
Im posting this on behalf of a friend. He has recently acquired a second hand guitar with a BH pickup in it. However he seems to be getting a lot of feedback from it-this doesnt happen with any of his other guitars. The noise goes away when he rolls the volume down on the guitar or uses the killswitch. However it doesnt go while playing the guitar. Here are some pics of the electronics and the pickup height-what do you think is the most likely cause for this?
Thanks guys
(http://i1217.photobucket.com/albums/dd386/witeter1/1538907_402651226533731_1515588018_n_zps65ef242f.jpg) (http://s1217.photobucket.com/user/witeter1/media/1538907_402651226533731_1515588018_n_zps65ef242f.jpg.html)
(http://i1217.photobucket.com/albums/dd386/witeter1/1525535_403012643164256_392069440_n_zps8040d5d6.jpg) (http://s1217.photobucket.com/user/witeter1/media/1525535_403012643164256_392069440_n_zps8040d5d6.jpg.html)
Title: Re: Blackhawk feedback issue
Post by: witeter on December 31, 2013, 11:35:55 AM
Oh and its also there even through the clean channel
Title: Re: Blackhawk feedback issue
Post by: Keven on December 31, 2013, 12:22:25 PM
i can't make it out from the picture but is there a ground going from the bridge to the rest of the electronics? i can see one wire going to the pickup but not really any distinct ground.
Title: Re: Blackhawk feedback issue
Post by: witeter on December 31, 2013, 12:37:57 PM
Cheers Keven - this may help?
(http://i1217.photobucket.com/albums/dd386/witeter1/1508526_403036136495240_1606041560_n_zps745027e3.jpg) (http://s1217.photobucket.com/user/witeter1/media/1508526_403036136495240_1606041560_n_zps745027e3.jpg.html)
Title: Re: Blackhawk feedback issue
Post by: silence2-38554 on December 31, 2013, 05:08:59 PM
i can't make it out from the picture but is there a ground going from the bridge to the rest of the electronics? i can see one wire going to the pickup but not really any distinct ground.

I agree.  First thing I'd check out is that there is a functional ground wire running from the guitar's bridge to the electronics.  Second, verify that the cavity is coated with electrical shielding rather than just black paint. 
Title: Re: Blackhawk feedback issue
Post by: Potatohead on January 01, 2014, 12:33:19 AM
I agree with above, doesn't look like the cavity is shielded unless that's some funky paint. I'd still get some copper shielding for it if it was.
Title: Re: Blackhawk feedback issue
Post by: FELINEGUITARS on January 01, 2014, 03:00:41 AM
if we are talking abot microphonic squeel feedback then only wax potting the pickup again will help

Try tapping the top of the pickup with a finger or pick - if you her it loud and clear then the pickup needs wax dipping

You can send it back to BKP or find a tech who offers the service (like us)

the black/grey paint is likely to be a carbon or nickel screening paint

is the guitar a Sabre? ( the recessed jack looks like one of their designs)
Title: Re: Blackhawk feedback issue
Post by: Dave Sloven on January 01, 2014, 05:47:36 AM
It's easy to test the shielding with a continuity check beeper on a multimeter.

Shielding paint comes in a couple of different colours.

I can't see a bridge ground wire in the photos.
Title: Re: Blackhawk feedback issue
Post by: witeter on January 01, 2014, 08:28:13 AM
Thanks a lot guys, i will feed all your input back. Seems that the obvious one is the ground wire? how does he go about fixing this? sorry, but im a complete noob when it comes to electronics also  :(
Jonathan-yes its a Sabre he acquired second hand, the current owner lives in Holland though, but if its wax dipping thats needed i will give him your details  :D