Double Bass Full Circle issues

[ole Jason]

Last Saturday I got to a gig only to discover my Full Circle was not working at all despite being fine the day prior. There was zero signal, no cutting in or out, just nothing whatsover. I tried turning the wheel, jiggling the cable, reseating the jack, etc. but no dice. I did the gig unplugged and just figured the pickup died so back to Fishman it went. I had a bunch of gigs this week so I ordered a new pickup and just figured I'd have a backup onhand when the original was repaired.

Cut to last night and the exact same thing happened at a gig with the new pickup. After turning the wheel and jiggling things I got the pickup working and had no more problems the rest of the night. I had another gig this morning and the same thing happened yet again. What I noticed today is that turning the wheel seemed to affect the amount of signal being passed. It went from zero signal, to a very very weak signal, and finally full signal.

The problem sounds like the pickup isn't being squeezed sufficiently but it is definitely sitting flush. On my bass the threads are down so the wheel is flush against the top (string side) half of the bridge. Is that the problem? I was under the impression the FC can be installed threads up or down. My first pickup was installed by the Bass Cellar and worked without issue for ~6 months so I'm sure it was done correctly.

I'm kind of at a loss as to what I can even try here. There's really only one way I can install the pickup without changing bridges. I'm going to file out the bridge wings today so I can install a Vick's pickup as a backup if I get to a gig and this thing isn't working. I'm pretty sure Fishman is going to tell me the original pickup is fine since something else seems to be going on. This has been a frustrating, and expensive, week.

For clarity my cables, amp, cab, etc. are all fine. The problem definitely lies with the pickup/bass somehow.

 

[Ric Vice]

Thing is it’s possible that you have dirty input jacks, or effects in/out loops. So I’d try cleaning all the jacks with DeOxit 5 it’s easily
done and costs virtually nothing. just a thought. While it’s possible you could two defective full circle’s it’s highly unlikely.

 

[ole Jason]

Thing is it’s possible that you have dirty input jacks, or effects in/out loops. So I’d try cleaning all the jacks with DeOxit 5 it’s easily
done and costs virtually nothing. just a thought. While it’s possible you could two defective full circle’s it’s highly unlikely.

It definitely isn't the amp or any part of that end because I use all of that stuff for my electric bass. I've used different amps just to be sure though. I thought it could be the output jack from the pickup but I have an old bass w/ a Full Circle and I swapped the barrel/input end over to that bass and it worked totally fine. It really seems like the problem is somehow related to how it is mounted but I can't figure it out. I'm going to take the bridge apart tomorrow and make sure there isn't any dust or anything in between the flat edge of the bridge and the wheel. I can't think of anything else it could be, I agree that getting two defective pickups would be incredibly unlikely.

 

[ole Jason]

I spent some time on it yesterday and the problem is indeed the connection between the pickup/wheel and the top half of the bridge. I lightly sanded the flat part of the bridge the adjuster wheel abuts to remove any debris and that seems to have helped somewhat but the pickup still cuts in and out if I turn the wheel. If I gently push the bridge in towards the top that will usually make the pickup work so it's almost like there isn't enough consistent downward pressure.

Oddly enough I've been thinking about trying a stark E and I think that may also help here since it would increase the amount of pressure through the bridge to the pickup. I plan on trying that soon. In the meantime the FC does work if I mess around with it. I also filed out the bridge wing so I can get a Vic's pickup on the bass if needed at a gig. Pretty disappointed the FC seems so sensitive but I guess at the end of the day the problem lies with my bridge/bass.

 

[DoubleMIDI]

The contact area needs not only to be flat but also parallel to the disc. You might file the corners a little bit more to avoid space in the middle part where the piezo sits.

 

[bassmanbrent]

I'm sure you've already done this but check to make sure your bridge is not leaning towards the fingerboard.I had an issue with distortion from my FC at one point and truing up the bridge solved it. I was really surprised by how little things needed to be askew to cause problems but happy I was able to fix it.

 

[ole Jason]

The contact area needs not only to be flat but also parallel to the disc. You might file the corners a little bit more to avoid space in the middle part where the piezo sits.

Thanks I will try that. When I was testing things out it was a little unclear exactly where the piezo sits. I have plenty of adjustment room on the bridge so if all else fails I can put it on the belt sander and take off enough material get it completely flat.

I'll also double check the bridge lean, it seemed pretty solid but I'll see if anything moved overnight after it sat with the strings at pitch

 

[ole Jason]

I had more problems on a gig last night with it cutting in and out, although it was somewhat better. Today I took the bridge apart again and put the contact area on a belt sander to get it as flat as possible. I also made sure the bridge wasn't leaning, it seems okay so far but I'll keep an eye on it as the day progresses in case it moves after bringing everything up to pitch. As of right now the pickup is working even when twisting the adjustment wheel

I also sanded both bridge wings so I could install the Vic's pickup. It looks goofy having both pickups on at the same time but that's better than being dead in the water at a gig. My next job is Friday so I plan on practicing with the amp at home this week to try to shake out anymore issues.

I'm pretty impressed with the Vic's pickup. It sounds less colored than the FC although it doesn't have as much output.

 

[ole Jason]

lol This thing still doesn't work. I'm at my wit's end with it. It works fine at home but by the time I get to a gig it's completely dead every single time. I think I'm just going to get a Lifeline and see if that will work. Failing that I guess it's time for a new bridge.

 

[Endlesssolo]

lol This thing still doesn't work. I'm at my wit's end with it. It works fine at home but by the time I get to a gig it's completely dead every single time. I think I'm just going to get a Lifeline and see if that will work. Failing that I guess it's time for a new bridge.

Reading through the replies, the only thing that makes sense to me, and this is a real long shot, is that the hole in the upper part of your bridge might not be deep enough or is somehow obstructed, to allow the pickup to make solid contact with the bottom of the upper pat of the bridge.

I don’t know if this is related, but recently I switched from the full circle to a Yamahiko, which mounts the same way. When I first installed it, it distorted pretty badly; (different from the other distortion due to too-high output on this pickup) so I took the bridge off and very carefully lap sanded (do you know what I mean, basically rubbing it back and forth over a piece of sandpaper glued to a very flat surface) and worked carefully to get that surface as flat as possible. Re-installed, made sure the bridge was really straight, and that the upper part of the bridge was sitting really flat and straight on the pickup element, and it worked great.

The Yamahiko is a good alternative to the full circle; it sounds pretty similar but is a bit brighter. The only issue is that the output is very high and that was causing clipping on the lower notes regardless of volume or amp setting. So I made the modification of installing 3.3nf capacitor bridging the two contacts of a patch cord; this cuts the output voltage substantially. That totally fixed the problem.

 

[Jim Dombrowski]

You can send your Full Circle back to Fishman. It's a $50 bench charge for them to assess whether to replace or repair it.

 

[ole Jason]

You can send your Full Circle back to Fishman. It's a $50 bench charge for them to assess whether to replace or repair it.

I have one with them now. I don't think the pickup is the problem in my case.

Lap sanded the bridge yesterday and re-leveled everything. The pickup is working at home with no issue. I'll try it at my next gig but pretty much have zero confidence in the setup at this point. I've used the Vic's pickup on the last few gigs.

 

[Don Hergert]

Sorry to read of all your problems, but very glad you've got the Vic's as a backup.

 

[Bruce Calin]

As I've said in many various posts, my main concern on a gig is reliability. I would've used the Vic's to begin with: decent sound and total reliability. I use an EAP for guieter and more sound oriented work, but I wouldn't hesitate to use the Vic's in any situation if necessary.

 

[turf3]

Have you considered the theory above that the unthreaded part is bottoming in the holes, thus preventing full contact pressure against that side of the pickup/wheel?

I've known an awful lot of people who use the Full Circle and haven't heard much bad about them.

 

[ole Jason]

Have you considered the theory above that the unthreaded part is bottoming in the holes, thus preventing full contact pressure against that side of the pickup/wheel?

I've known an awful lot of people who use the Full Circle and haven't heard much bad about them.

Yes of course, that isn't the issue unfortunately. At this point I don't think the problem has a singular cause but is likely a few small things adding up.

I've known lots of people who are happy with the Full Circle too but that doesn't help me much. This thread obviously wasn't made to imply that the Full Circle has widespread issues or whatever. This is a problem with my bass/bridge specifically.

 

[Thed S]

Yes of course, that isn't the issue unfortunately. At this point I don't think the problem has a singular cause but is likely a few small things adding up.

I've known lots of people who are happy with the Full Circle too but that doesn't help me much. This thread obviously wasn't made to imply that the Full Circle has widespread issues or whatever. This is a problem with my bass/bridge specifically.

How long had you been using the FC before the first one went bad? I got mine from a friend when the line to the barrel plug in came off. I added a short bit of wire to it, and soldered it to the barrel jack. It’s been working fine for a few years now. Your problem sounds very frustrating; it’s one of those Murphy’s Law gremlins that’s so hard to pinpoint.

 

[ole Jason]

How long had you been using the FC before the first one went bad? I got mine from a friend when the line to the barrel plug in came off. I added a short bit of wire to it, and soldered it to the barrel jack. It's been working fine for a few years now. Your problem sounds very frustrating; it's one of those Murphy's Law gremlins that's so hard to pinpoint.

Around 6 months or so. Interestingly enough today I got a shipping notice from Fishman saying they've replaced the original FC I sent in... which leads me to believe it was either truly faulty or they didn't have time to evaluate it and just replaced it. If it hadn't been faulty they would have charged me (which I was expecting and fine with).

So that begs the question why I'm having issues with the new one I just put on. Yesterday I plugged it in and it was completely dead, turned the adjuster a half turn and it started working, moved it back to the original position and it still works. There's really no rhyme or reason as to when it works and when it doesn't. Once the replacement arrives I'll put it on and see where that gets me. I think the chances of having three faulty FC in a row is virtually zero so that will at least give me some peace of mind lol.

 

[Chris Fitzgerald]

It’s an interesting thread. I’m beginning to wonder if the fact that I’ve had such good luck with my FC pickups over the years is that they were installed by Nnick Lloyd, who took great pains to make sure the part of the bridge that contacted the wheel was perfectly flat on both basses.

In 20 years I have had two failures: one was the old model with the two halves of the wheel glued instead of screwed, and Fishman replaced that one. The second was my fault, where the wire got broken by my carelessness. That time, I just said “D’oh!” and went out and got another one. The two on my basses now have been on for over 10 years each.

 

[jmlee]

I've had a number of FCs, and I think that one important issue is making sure that your bridge stays vertical over time, not exerting too much stress on one aspect of the adjuster. I'm not always a perfect citizen about monitoring this bit of basic maintenance.

Of course, one time some foster kittens chewed through the lead. I was at a rehearsal, baffled by why I was getting no signal. Then I noticed two half-cables with many, many tiny toothmarks.