Double Bass How to clean/fix barrel style input jacks

[Chris Fitzgerald]

I have a student who has been having some issues with the input jack on his Full Circle pickup. It was making intermittent crackling noises when the cable would move, but when you held the cable in place, it worked fine. I temporarily fixed the problem at a rehearsal yesterday by turning the mount upside down on the afterlength, which seems to hold the cable in place for now.

On the old style BG input jacks under the pick guard, when this happened it was always simple enough to just remove the pick guard and bend then prong back to where it held firmly. But what to do with a barrel style input jack? Deoxit? Or is there a way to tighten that connection when you can’t take the unit apart?

 

[Ric Vice]

I’d try putting some DeOxit 5 on a long cotton swab and cleaning the inside of the barrel jack throughly. The Full Citcle Jack actually has a in line resistor inside that I believe works like a HPF. If that’s “bunged up” it could be causing problems. If the cable has a short on the jack end you can buy a new one from Fishman. Just don’t try to replace it with a standard female 1/4 inch jack.

 

[Zooberwerx]

Hate to say it but, on the tech side, we've pretty much treated them as consumables. They're inexpensive, not THAT difficult to replace, and require only the most basic of soldering skills. Their compact footprint makes them the component-of-choice when real estate is at a premium. Switchcraft is highly regarded as the go-to but the most durable I've encountered is the stock jack on my 30+ y.o. Fernandes (MIJ). FC is strange agent as it includes circuitry within the 1/4" jack...here's one of your older threads:

Double Bass Thread 'Full Circle jack repair?'

Oct 7, 2016

On of my basses has a Full Circle where the wire was crimped up next to the jack and is intermittently shorting out. I can see exposed wire and would like to repair it. How easy a repair is this? Anybody ever done it?

• Chris Fitzgerald
• full full circle jack
• Replies: 41
• Forum: Amps, Mics & Pickups [DB]

Riis

 

[Wasnex]

I have used rubber bands to place a small amount of tension on the plug, so the static does not occur.

Otherwise, IMHO the solution is to replace the jack.

 

[Wasnex]

Also, confirm the problem is not with the 1/4" plug (try a known good cable).

 

[Dirk Diggler]

Yes just replace it.
There is no reason to try and repair jacks, but that said it could be just the wiring.
If moving causes noise, the solder joints could be failing.

If the jack is internally mounted, you may need to extract it from the bass to check the wiring.
You might have to unscrew the nut from the inside I believe.

If it's mounted on the strings behind the bridge (like the pic above) then I would inspect the wiring as it's
all right there.

Barrel jacks really do suck, and they fail quite often. That's why replacement is best, also considering how
cheap a decent jack is these days.

And last FYI, it's actually an Output jack.

 

[Ric Vice]

Actually, in my case, so far so good ( fingers crossed) The Ehrlund EAP (in combination with a RedEye Twin) is going on 10 years without incident.
Perhaps I’m the exception to the rule, hard to say.

 

[bassmanbrent]

Barrel jacks really do suck, and they fail quite often. That's why replacement is best, also considering how
cheap a decent jack is these days.

As noted above, this is not a standard output jack, so unless one can be sourced from Fishman, the sound of the p/u will change. Likely not for the better.

 

[Thunderthumbs73]

I have a student who has been having some issues with the input jack on his Full Circle pickup. It was making intermittent crackling noises when the cable would move, but when you held the cable in place, it worked fine. I temporarily fixed the problem at a rehearsal yesterday by turning the mount upside down on the afterlength, which seems to hold the cable in place for now.

On the old style BG input jacks under the pick guard, when this happened it was always simple enough to just remove the pick guard and bend then prong back to where it held firmly. But what to do with a barrel style input jack? Deoxit? Or is there a way to tighten that connection when you can’t take the unit apart?

Like other people say but Dexoit and Q-tip. I'm responding because I'll add one more thing: very fine grade of sandpaper wrapped around a jewler's screwdriver or whatever is JUST small enough to fit in the jack, turn both screwdriver and sandpaper wrapped around it, and allow the sandpaper or ever-so-slightly PHYSICALLY remove oxidation and THEN Dexoit after that. That's my process for such things. For the noise you describe, I'd start there and that way.

 

[aprod]

Spray the Deoxit on a a 1/4 inch plug and insert it into the jack a few times.

 

[dylanjohnson]

I have a student who has been having some issues with the input jack on his Full Circle pickup. It was making intermittent crackling noises when the cable would move, but when you held the cable in place, it worked fine. I temporarily fixed the problem at a rehearsal yesterday by turning the mount upside down on the afterlength, which seems to hold the cable in place for now.

On the old style BG input jacks under the pick guard, when this happened it was always simple enough to just remove the pick guard and bend then prong back to where it held firmly. But what to do with a barrel style input jack? Deoxit? Or is there a way to tighten that connection when you can’t take the unit apart?

I had this happen and it ended up getting worse and worse. Barrel jacks in general are HORRIBLE. I believe Fishman puts a capacitor or something in that housing, too (as Ric and others mentioned). Eventually the best thing to do is to get a replacement jack from them, move the mount from the old one, and plug the RCA jack in (which also gets worn out so tell them not to plug that in and out too much.

 

[fdeck]

Try some different brands of cables. Whatever you can lay your hands on for the moment. The precise geometry of a 1/4" plug tip varies slightly from brand to brand. A different plug might solve the problem.

 

[DoubleMIDI]

I would first check the cable at the RCA plug. If wiggling the cable there shows the problem too (and probably more intense) open the RCA and check for loose solder points, broken cable and possible shorts.

AFAIK, there is a capacitor inside the adapter (hot to shield) to lower the output voltage without a bad influence on output impedance.
I no longer have a Full Circle (replaced by a Yamahiko), so I cannot measure the value myself. Measuring from hot to shield with the RCA plug disconnected with a multimeter with a capacitance range will give the value.

If you have proven that it really is the RCA to 1/4“ adapter and really want a different jack, get a foil capacitor of that value (warning, some might not fit into a 1/4“ jack) and a quality jack if you really need to replace the adapter.
Preparing the white cable for soldering to the 1/4 jack might not be easy as the white isolation is hard to cut without cutting the shield and probably even the hot wire inside too.
The easier way would be getting a new adapter from Fishman.

FDeck‘s advise using a different plug to connect to the amp/preamp is good. A different shape of the tip will make contact at a different position.

I would also clean the plugs of the connection cable to the amp and try a different cable to check if the connection cable is notches culprit.

 

[james condino]

Almost every pickup I've owned I cut the janky supplied connector jack off immediately and instal a $15 switchcraft acoustic guitar jack. It is literally two wires to solder back. If you don't have the skill set, any electric guitar or bass tech will do it for maybe $10 and a 5 minute wait.

Bonus that it lowers the overall tailpiece mass compared to those big barreI jacks. I can then ream one of the tailpiece string sockets maybe a mm oversize and solidly mount it there, eliminating all of the tape / twistie / BS attachment thingies that they all seem to come with and turn it into a bombproof connection that elimiantes some stagehand / bandmember / club owner stepping on my cable and ripping the pickup off my bass. 'Best $15 you'll ever spend on a pickup. I've gotten so used to this setup that when I purchase a new pickup from the manuufacturer, I specifically ask for no jack so I can connect my own. On some models, like the VIC's Model B, it brings the cost down to under $40...

No chance from Fishman; they have a goldmine in broken Full Circles! The fact that they charge $200+ new and then ask for another $50 to warranty a known probem is astonishing to me. Most of the other folks send me a free replacement with no questions asked on the rare occasions when I have troubles.YMMV

 

[Chris Fitzgerald]

Thanks for the replies. The student decided to just get a replacement barrel plug from Fishman. He’s overall happy with the pickup sound and doesn’t want to worry about the loose connection.

I’ve read a fair amount of frustration and even something approaching hate of the FC on the board, and I understand that bad experiences can turn anyone against any product. It happens to all of us.

But my experiences have been largely positive, and I can at least imagine why the pickup is designed as it is. The adjuster contains the piezo elements and there is probably not room for the capacitor in there, so it has to go in the jack. Could they have done this without using a barrel jack? Probably, but because of the nature of adjuster wheel they had to either choose a design where the cable can be disconnected at the wheel or at the jack so the wheel can turn. I get it.

The Yamahiko design, which I understand predates the FC, disconnects at the wheel, and I haven’t heard a lot of stories of failures of this design. However, I have read a fair bit about the output being too hot and people having to solder in remedies into their patch cables, which sounds like a nightmare to me. So pretty much every option is a compromise of one sort or another.

 

[Earl]

Thanks for the replies. The student decided to just get a replacement barrel plug from Fishman. He’s overall happy with the pickup sound and doesn’t want to worry about the loose connection.

I’ve read a fair amount of frustration and even something approaching hate of the FC on the board, and I understand that bad experiences can turn anyone against any product. It happens to all of us.

But my experiences have been largely positive, and I can at least imagine why the pickup is designed as it is. The adjuster contains the piezo elements and there is probably not room for the capacitor in there, so it has to go in the jack. Could they have done this without using a barrel jack? Probably, but because of the nature of adjuster wheel they had to either choose a design where the cable can be disconnected at the wheel or at the jack so the wheel can turn. I get it.

The Yamahiko design, which I understand predates the FC, disconnects at the wheel, and I haven’t heard a lot of stories of failures of this design. However, I have read a fair bit about the output being too hot and people having to solder in remedies into their patch cables, which sounds like a nightmare to me. So pretty much every option is a compromise of one sort or another.

In my experience, when you use the Yamahiko the way it was designed to be used - pickup on both sides, connected with the cable, there is no problem with the output being too hot. When only one pickup/side is used is when the output can be too hot.

 

[agedhorse]

Like other people say but Dexoit and Q-tip. I'm responding because I'll add one more thing: very fine grade of sandpaper wrapped around a jewler's screwdriver or whatever is JUST small enough to fit in the jack, turn both screwdriver and sandpaper wrapped around it, and allow the sandpaper or ever-so-slightly PHYSICALLY remove oxidation and THEN Dexoit after that. That's my process for such things. For the noise you describe, I'd start there and that way.

Never use any kind of sand paper, no matter how fine. This will damage the NiAg plating on the contact surfaces. Once that’s damaged, the jack is ruined and must be replaced.

The plating is less than a thousandth of an inch thick.