UST piezo replacement? (Fishman Aero/Presys)

ruger9 · #1 08-12-2017, 11:42 PM

My Walden has a Fishman Aero+ (which I think is just an OEM version of the Presys+) system... and the high E string is quieter than the others. I know this could be a "pressure issue" (bottom of saddle not completely flat when it was sanded down), but I've also read many here who have said "better to just replace the UST", that way you know it's good."

I contacted Fishman and they want $65 for the UST. But, I see many versions for sale for alot less, they say they are compatible with the Fishman system (I know there has to be an impedance match).... are these OK? Has anyone bought one?

(these can generally be found on ebay)
http://www.ebay.com/itm/Kmise-Z5216-...IAAOSwKytZNW8k

jonfields45 · #2 08-13-2017, 06:24 AM

Unlike the Matrix UST which is fairly fragile (one of the conductors is the shield) and easily damaged, most coax USTs are fairly robust. In theory you can kink and short a coax UST at the entry point to the saddle slot but I've never encountered that problem and have seen coax USTs installed in vertical Matrix-style drill holes with no problems. At that price there is no great loss in giving it a try, but I think some saddle work to make that e-string louder is a better first action. The listing makes no claim to be the real thing, but that does not mean it won't work.

Generally the very end of a coax UST (near the high-e) produces no output. It is possible the UST has shifted slightly into the guitar body and just needs to be placed as far into the saddle slot as possible.

Next, a very simple way to try to fix the high-e is to remove the saddle and tape off the bottom except for the high-e. Paint the section under the high-e with 3 coats of thin cyanoacrylate glue. Remove the tape and file off any lip of glue that formed in the painted area, reinstall, and test. It might take 1-3 repeats of this procedure. I used this procedure on my main guitar that has a Baggs Element based Mi-Si trio. In my case the low e was too loud and I painted the rest of the saddle bottom. 6 coats did the trick.

ruger9 · #3 08-13-2017, 07:16 AM

Quote:

Originally Posted by jonfields45

Generally the very end of a coax UST (near the high-e) produces no output. It is possible the UST has shifted slightly into the guitar body and just needs to be placed as far into the saddle slot as possible.

Next, a very simple way to try to fix the high-e is to remove the saddle and tape off the bottom except for the high-e. Paint the section under the high-e with 3 coats of thin cyanoacrylate glue. Remove the tape and file off any lip of glue that formed in the painted area, reinstall, and test. It might take 1-3 repeats of this procedure. I used this procedure on main guitar that has a Baggs Element based Mi-Si trio. In my case the low e was too loud and I painted the rest of the saddle bottom. 6 coats did the trick.

Thanks so much for this info, IDK the very end of the coax produces no signal; I'll check it's positioning today when I change strings, and if that doesn't work, I'll try the glue fix (I was thinking perhaps a shim under the UST, under the just the high E, for better contact... but the glue is a more permanent idea.

I'm pretty sure the bottom of the saddle is flat, as I sanded it myself, being careful to insure it's flatness for this very reason. And the high E wasn't quiet before, but is now, so hopefully perhaps during the last string change, something shifted.

Christopher Cozad · #4 08-13-2017, 11:12 AM

I believe Jon's advice is excellent, and I would be surprised if it doesn't help you. But, after applying the CA glue test/fix, should you still find your UST wanting, consider that we often assume routed saddle slots are dead flat, and that is often not the case. We also assume that there is consistent quality control for all Under Saddle Transducers, and they all output evenly across their length, and that is also not true.

Short of replacing your pickup, there are a couple of additional "tricks" that can aid in the proper fitting of a UST and, rather than write it all again, I will link to some very valuable information contained in the LR Baggs Element Installation Manual, located here (as of the time of this post).

ruger9 · #5 08-13-2017, 01:15 PM

Thanks Chris. More good things to consider.

I would normally just buy a new UST if for no other reason than to eliminate it from the equation. But with the info you gave, now I DEFINITELY don't want to spend $65 instead of $10.

I don't play plugged in alot, but I'm 90% sure this "quiet high E" wasn't a problem before, which would make it either the UST shifting, or I guess going bad....

QUESTION: if the high E is quiet electrically because of a "poor contact" on that part of the saddle, would the same thing happen acoustically?

Christopher Cozad · #6 08-13-2017, 02:14 PM

Quote:

Originally Posted by ruger9

...QUESTION: if the high E is quiet electrically because of a "poor contact" on that part of the saddle, would the same thing happen acoustically?

That is a very sensible question. My simple answer is "sort of".

All other things being equal (bracing is intact, soundboard isn't damaged, etc, etc.):

If the trouble is truly known to be occurring at the saddle alone (there is zero fret contact by the string - I know, but you might be surprised... - , and the nut / nut slot has been proven to *not* be a factor), and you have ruled out poor contact at the crown of the saddle, you may or may not "hear" the less-than-optimal condition of the 1st string, un-amplified. An Under Saddle Transducer is 100% dependent upon perfect contact, being sandwiched between saddle and bridge slot, and will readily give away a contact-compromised condition. Determining whether that condition is due to non-optimal contact or pickup failure is where the detective work comes in.

Assuming you have a capo, a pinned bridge, and a little time, it is a relatively simple matter to capo the strings, loosen the strings, remove the end pins, remove the strings from the bridge (leave them capo'ed for ease of putting them back in place) and then carefully removing the saddle in order to check on the condition/location of the UST.

Shifting of a UST can occur, but typically does not, at least not under string tension. It would take some serious help to slide a UST, especially one that is working just fine - indicating good contact - when it is being pressed into place by a downward force exceeding 150 lbs.

Perhaps a saddle was removed, the UST shifted, the saddle was re-installed...

ruger9 · #7 08-13-2017, 06:21 PM

Quote:

Originally Posted by Christopher Cozad

Determining whether that condition is due to non-optimal contact or pickup failure is where the detective work comes in.

Exactly. I CAN say the OPEN E has no "diminuitive" properties, compared to the others, acoustically. Only plugged in. That should rule out frets.

Quote:

Originally Posted by Christopher Cozad

Perhaps a saddle was removed, the UST shifted, the saddle was re-installed...

Well, I did remove it to shape it (lower the action), but that was years ago.... hmm...

I didn't have time today, but I will definitely remove the saddle tomorrow and have a look.

ruger9 · #8 08-16-2017, 09:13 AM

well well well..... turns out I did NOT sand the saddle completely flat. Can't hear it acoustically, and I rarely plug this guitar is, which is why I didn't notice it until recently.

In the process of adding CA layers... I don't want to sand, as this guitar plays EXACTLY how I want it, and don't want to lower the action at all. Thanks for the tips!

Christopher Cozad · #9 08-16-2017, 11:24 AM

Quote:

Originally Posted by ruger9

well well well..... turns out I did NOT sand the saddle completely flat. Can't hear it acoustically, and I rarely plug this guitar is, which is why I didn't notice it until recently.

In the process of adding CA layers... I don't want to sand, as this guitar plays EXACTLY how I want it, and don't want to lower the action at all. Thanks for the tips!

Brilliant! Good detective work, and kudos to Jon for the "fix". It is always nice to hear a positive outcome.

jonfields45 · #10 09-03-2017, 07:48 AM

New guitar (RainSong CH-PA1100NS), new pickup install (Mi-Si Trio), and first gig last night. It felt like the high E was weak.

I take it apart this morning and see that when I tied down the cable in the guitar as the last action of the install, I must have pulled the Element UST about 1/4" into the guitar body. It amazes me the high E sounded as good as it did and passed my first sound check at my bench after install. It also amazes me I did not check the UST placement before stringing up when I did the install.

Well at least it was an easy fix. And even the guy I play with did not feel he could confirm my complaint, so no great loss. Sounds great this morning...

Christopher Cozad · #11 09-03-2017, 10:23 AM

Quote:

Originally Posted by jonfields45

...It also amazes me I did not check the UST placement before stringing up when I did the install...

I had to smile, as that is such an easy step to overlook, and has bitten me more than once over the years. I am sure someone will benefit from your having shared that story. (And don't you just love the convenience of the Mi-Si? I have been having loads of fun with them, in various configurations.)