Fishman Archtop Bridge weak on Bass side

[Len Biglin]

Hi all , I have been looking at a nice archtop guitar , the owner installed a Fishman archtop bridge/pickup and asked to to rectify a very weak output from E A & D . It was very noticable , all I could do was switch it end for end , but it was still the same . There is plenty of break angle , and he uses Thomastic flatwound strings. Any ideas ?

[Pierre-Antoine Roiron]

I don't think you can do anything about it since it's an all packed-up piezzo pickup without any access to it. I would tell him to have it exchange under guarantee, so you can check it's not a problem with the pickup itself.

[Thomas James]

Just thinking... does it respond better to a non-flatwound bass string?

[Russell Vance]

Hi Len, I was thinking the same as Thomas - are the Thomastiks the silk inlay type - and being flat-wound they are "dead as" by design....string it up with a standard roundwound heavy set and see if it evens out. Also, if the Thomastiks are of the low tension variety they simply may be loading the bridge asymmetrically and not getting enough "ooomh" into the embedded piezo elements.  

Another place to check is the trapeze tailpiece mount - make sure it is not twisted/distorted "up" on the bass side thereby decreasing the break angle across the bridge for the bass strings.    

And, rather agriculturally, connect the bare bridge unit up, off the guitar, and evenly tap along the top with a chop stick (or whatever, -a  6 lb sledgehammer is an option if the problem causes stress) without strings or tension - if it sounds about the same from one side to the other its a good start. Given that the problem doesn't switch ends when the bridge is reversed/flipped I think it is not the pickup here.  Apart from that Len, hope yr traveling well in 2012. Rusty.

[Grahame Myers]

I'd suspect the Thomastiks too, they don't work well with piezo element systems. I'm of the opinion that it's due to the flat wound construction, and not the tension: Other low tension strings like Savarez Argentines on Maccaferri-type  guitars work perfectly well with piezo systems, and they're low tension too: They're wound with silver-plated copper, and have a thin core with very low tension. 

[Len Biglin]

Thanks Guys , Yes it is pointing to the strings , there is plenty of drive on the plain strings , and when switched end to end the problem stays with the bass side . Logic suggests some more normal strings Thanks again , and Hi Rusty Im doing well and busy as ever , hope you are too.

[John Morton]

When you say "still the same", do you mean the bass side is weak even after turning the bridge around, or that the same end of the bridge (which is now the treble end) is weak?

If it's the latter:  I installed one which was out of balance.  I removed it and inspected the piezo discs.  They were recessed into sockets in the lower bridge piece, but one socket was slightly too deep.  This caused the upper section to bear partially on the wood, and not fully on the piezo disc.  The cure was to put a small brass washer on top of each disc to make them taller.

John

[Len Biglin]

Hi John , this is a sealed saddle with piezo inside , and the problem stays with wound strings which ever way the bridge is installed , so it looks like a string issue .