Author Topic: LOW E sounds muffled on piezo only  (Read 6925 times)

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Offline fastelder

Re: LOW E sounds muffled on piezo only
« Reply #25 on: October 07, 2014, 08:16:50 AM »
Well, this is a long time coming.  It seems that on the Godin saddle pickups, the thin wire is NOT soldered, but GLUED!

One of my saddles had very weak response, and seemed to get worse when I was in a humid/sweaty situation.  I pulled the piezo "cap" off the saddle and sure enough the wire was loose.  What looked strange was that the area it was attached was blackened.  Was it scorched when attached?  This caused me to research before I finally got the courage to set it up to solder.  I realized this would be a one-shot deal due to the tin insulation.  It was then I hit upon the thought of wire glue.

After doing much research, I am now convinced that the piezo is glued to the wire via a carbon based glue.  It wasn't until I got the glue the other day that I found out the glue is WATER soluble, hence the humid/sweat failures.  The glue manufacturer even suggests coating the joint with a clear cover like Superglue to protect it.

So I feel the mystery is now solved!
Gr-55, Gr-20
GT-10
Digitech RP1000
Carvin SH-575
Godin XtSa
Fender RolandReady Strat

Offline OldGuitarDude

Re: LOW E sounds muffled on piezo only
« Reply #26 on: October 07, 2014, 08:52:49 PM »
Thank You fastelder for that info! I see Radio Shack stocks that, and there's one nearby. I'll grab a tube and keep it handy, hoping I'll never need it.... but I constantly play with the heel of my hand on the bridge, so chances are....

OldGuitarDude

Offline Elantric

Re: LOW E sounds muffled on piezo only
« Reply #27 on: March 24, 2016, 01:41:59 PM »
Piezo failure experiences ( Solution: add dedicated Ground Wires!)
http://www.vguitarforums.com/smf/index.php?topic=12657.0

Offline CK1

Re: LOW E sounds muffled on piezo only
« Reply #28 on: March 20, 2017, 07:05:01 PM »
Sorry to dredge up an old topic, but I've been dealing with this, too (low output on a single string) with a 2012 LGXT that I just bought.  I went through extensive testing of ground connections and could find nothing. Took apart the bridge piece, and found the same black glue mentioned above, but my wire was still strongly attached.  Attempted to clean any corrosion with both Deoxit and isopropyl alcohol, but to no avail. 

I have an email into RMC to find out exactly how the piezo strip is attached to the underside of the bridge piece, and to see if there are additional suggestions for trouble-shooting.  I have read a few places where guys are claiming that piezo elements go bad after a certain number of years, but I've never had that issue in my life.  So, I'm curious what response I'll get, and will report back for the benefit of others having similar issues.   

Offline lespauled

Re: LOW E sounds muffled on piezo only
« Reply #29 on: March 21, 2017, 08:31:09 AM »
This is from an email from Godin, that worked for me.

Quote
You should try the following :

-change the 9V battery
-remove the strings, pull out the defective piezo saddle and gently twist the cable
-clean the piezo saddles with isopropyl alcohol
-spray contact cleaner on the preamp and the output assembly's circuit boards

Also was a little stunned that they told me that I would have to return to the dealer that I bought the guitar from, not the closest one.  :o

Thankfully, it didn't come to that.

Offline CK1

Re: LOW E sounds muffled on piezo only
« Reply #30 on: March 21, 2017, 09:01:27 AM »
This is from an email from Godin, that worked for me.

Also was a little stunned that they told me that I would have to return to the dealer that I bought the guitar from, not the closest one.  :o

Thankfully, it didn't come to that.

Literally tried all of those, to no avail.  But I've already heard back from RMC, and will update here what I figure out.

Offline CK1

Re: LOW E sounds muffled on piezo only
« Reply #31 on: March 21, 2017, 12:17:29 PM »
OK, here's where I'm at, at this point.  I've had a number of email exchanges with Richard McClish/RMC, and they have been enlightening.  I'll preface my response by saying that I'm a reasonably accomplished electronics tinkerer who fixes guitars, builds stompboxes, etc.  So, I'm not clueless with this stuff, and tried to ask next-level questions to really understand what was happening.  Should some admin want to "sticky" this, I can do a cleaner write-up at some point.

My findings:


RMC "flash solders" the piezo connections on the bottom of the gold bridge piece caps, so as to keep the piezoelectric charge.  The mini coaxial cable (which carries the signal) is then attached using an electrically-conductive adhesive that he didn't name, but is referred to by a previous post as "carbon glue" of some kind.  He did not say if the one they use is water soluble, and my guess is that it isn't. However, either the glue or the connecting piece is clearly affected by moisture, as evidenced by the countless issues documented here and other places on the interwebs.  The ground portion of the cable connects with the underside of the lower gold bridge piece.  Then, that wire is connected to 2 pads (one for ground, one for signal) on the pc board. 

Grounding and moisture issues can cause complete loss of signal, as has been posted here at great length.  But for lowered signal levels, Richard claims that there is most likely impact and/or excessive force damage to the sensor.  He thought it could have occurred in shipping, which is possible in my case, though strange that it would only affect one saddle. Either way, he said that there is no fix for this, other than replacement.  I grudgingly agree, as I tried everything I could think of already, and haven't been able to repair it to full function. 

I know others have found that re-seating the saddle can fix their problem, and that's very possible if the issue is a loose connection (or possibly even corrosion).  But after talking with Richard, I think I need to trust his knowledge on piezo pickups, which is undoubtedly superior to mine, and just get a new one.  You can purchase directly through him at a cheaper price than I've found anywhere else online, though it's a bit of an ordeal because he doesn't take ANY forms of electronic payment.  But still nice that you can get just one. 

Also of note is that Godin installs these systems.  So, cold solder joints, open grounds, etc., are their responsibility, not the pickup manufacturer.  That said, the design's fragility rests with RMC, of course.

The positives:
- RMC is VERY responsive to emails (I received replies within one hour for every email), and willing to spell out information if necessary
- the price for a single saddle replacement is high, but far less than needing to replace an entire set
- Richard himself is a gentleman, and the interactions I've had with him have convinced me to work through the issues with my guitar instead of dumping it for something else

The negatives:
- despite claims that the system is fully functional, clearly there are significant weaknesses due to the fragility of these pickups and connectors, seeing as so many players have had issues with them
- even a new saddle is still exposed to air/moisture, and needs to be separately sealed (though this isn't too difficult, and could be done with super glue, nail polish, etc.)

If anyone reading this is having an issue with low output, checking the connections is still a good place to start.  But if they are solid, and using an anti-corrosive does not fix the problem, you most likely have a similar situation to mine.  I may still tinker with this, because it will be weeks before the new bridge saddle arrives (due to an RMC vacation).  So, if I make any subsequent discoveries, I'll update the post.

 

Offline admsustainiac

Re: LOW E sounds muffled on piezo only
« Reply #32 on: March 21, 2017, 01:28:20 PM »
When the piezo saddle went dead due to moisture from sweaty palms at a gig in a hot summer,  Ive had success reviving dead piezo saddle by using a hot air blower - just  a hair dryer on high setting aimed at the dead piezo saddle for 15 minutes.

Connect the guitar via 13 pin cable to your VG-99 / GR-55/ GP-10 and Use screwdriver and Periodically "Tap"  the problem Piezo Saddle while blowing hot air, and see if the signal is restored on the dead piezo saddle after a few minutes of hot air -

be careful not to use too much heat  - I placed aluminum foil as a protective heat shield surrounding the bridge - to protect the paint on my Godin xtSA.  - as too mush heat may damage your guitar finish   

   

Offline mccorp

Re: LOW E sounds muffled on piezo only
« Reply #33 on: August 21, 2017, 06:36:01 AM »
Thanks for the comments and suggestions offered in this thread. I had the best luck with the hair-dryer technique offered by admin. It worked wonderfully for me and in a short period of time. It is evident that moisture is the culprit and keeping it to a minimum it essential. I am wondering if storing silica gel in the case might be helpful during the months that are most humid.
« Last Edit: August 21, 2017, 09:46:50 AM by mccorp »
Sometimes you have to let go of the melody and focus on the rhythm

Offline snhirsch

Re: LOW E sounds muffled on piezo only
« Reply #34 on: August 21, 2017, 07:11:14 AM »
Thanks for the comments and suggestions offered in this thread. I had the best luck with the hair-dryer technique offered by admin. It worked wonderfully for me and in a short period of time. It is evident that moister is the culprit and keeping it to a minimum it essential. I am wondering if storing silica gel in the case might be helpful during the months that are most humid.

Installation of discrete ground wires is probably the only sure, long term fix.  Line 6 have their heads firmly stuck in the ground with regard to the transducer grounding issues.

Offline mccorp

Re: LOW E sounds muffled on piezo only
« Reply #35 on: August 21, 2017, 09:49:47 AM »
Installation of discrete ground wires is probably the only sure, long term fix.  Line 6 have their heads firmly stuck in the ground with regard to the transducer grounding issues.

Thanks for this information. Is this something that can be repaired or are you talking about a modification that needs to be built in at the ground level at the time the instrument is made?
« Last Edit: August 23, 2017, 12:57:28 PM by mccorp »
Sometimes you have to let go of the melody and focus on the rhythm

Offline admsustainiac

Re: LOW E sounds muffled on piezo only
« Reply #36 on: August 21, 2017, 10:08:04 AM »
Thanks for this information. I this something that can be repaired or are you talking about a modification that needs to be built in at the ground level at the time the instrument is made?

Read the details

Piezo failure experiences ( Solution: add dedicated Ground Wires!)
http://www.vguitarforums.com/smf/index.php?topic=12657.msg91984#msg91984