RMC - Notes regarding Piezo Tune-O-Matic type Bridges (Les Paul, LGXSA, etc)

Started by Elantric, March 03, 2008, 11:53:15 AM

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Elantric

Wayne - with the ghost / tonepros T.O.M. type Les Paul piezo bridge -
do you find you get odd anomalies from the 2 inch length of "non speaking" string length
behind the bridge? Most folks I know tend to discover improved sound
after inserting a piece of foam rubber under the strings back there -
to mute the strings between the bridge and the tailpiece- since the
peizo bridge cant discriminate between which side of the string it
should respond too. It picks up that region and rendors it as a hi
pitched out of tune artifact from the short string length behind the
bridge. Its a common complaint from Godin LGXSA owners too btw.

Elantric

> That's what I had to do. The piezos pick up the twang behind the
> saddles
> almost like the sympathetic vibrations of a sitar. The mags don't.
> Putting
> the foam there may hurt the tone/sustain a little bit. Maybe RMC could
> chime in on the technicals. Obviously the tailpiece is supposed to
> contribute a little. In my case it's a string-through- body which is
> supposed to be even better than a traditional tailpiece.

-=- Hi all,

When playing a note on a given string, the segment behind the saddle
gets excited by small pivotal movements of the played portion of the
string over the supporting saddle. This causes a ring mode in the
unplayed segment. A pickup saddle is equally sensitive to vibrations of
both string segments that it's supporting.

The string segments serving no musical purpose should be muted. You're
better off silencing all those wiggly/springy thingies and adding a
controllable amount of hi-pass filtered reverb, especially in high-gain
applications.

Also note that tune-o-matic bridges are notorious for resonating at a
high-frequency in a front-to-back pendulum mode. This results in a
distinctive ringing which can be heard by tapping the front face of the
bridge with a metallic object even if the string segments are damped,
and won't disappear unless the middle of the bridge is blocked
mechanically with a suitable damping support (like a hardwood block).

Best regards,

RMC


"Behind the Bridge" String Dampers




Elantric


Rorster

Elantric, That is gorgeous. I've got an LGX-SA and would have never dreamed of a mod like this. How about the response of the piezos since there is no foam under the strings back there behind the bridge? Did you install it yourself? Does the tuning stay put?

Elantric

I did the Xtrem install myself.
This revealed that the LGX-SA body has many internal air cavities. The Xtrem mounting screw nearest the treble side of the bridge had to be short, as this enters the internal piezo wire pass thru cavity in the body.

The goal was to minimize the string length between the piezo bridge and the tremolo, so the Xtrem is placed very close to the bridge. Observe the "non speaking string length between bridge and tailpiece is now 50% shorter, which helps tame odd Guitar to MIDI anomalies.

The Guitar sounds stock, zero anomalies or tracking problems when used for Guitar to MIDI or Guitar to PCM with GR-55 - its my current favorite 13 pin guitar. I was inspired by my JTV-59 Bigsby guitar - but the GFS X-Trem works much better on the Godin than any Bigsby.

I have recently swapped out Nickel for Black Xtrem - and replaced the crap stock tuners with Planet Waves  / Ned Steinberger 3+3 locking tuners. Its strung with D'addario 10-46 strings  - and stays in tune !

Only remaining mod will be installing Seymour Duncan Tripleshot series/parallel/coil tap switching pickup rings

Rorster

That's awesome. Was there any other reason you went with the black Xtrem other than your aesthetic taste? Also when you say "The Xtrem mounting screw nearest the treble side of the bridge had to be short, as this enters the internal piezo wire pass thru cavity in the body" I assume you're referring to the one right up under the high E string saddle and did the screw go all the way through the body? I would think that with the forces that the trem has to be able to withstand, it would require a real solid installation. Lastly, Ive been reading about the GP-10 here on the Forum and would like to know how it responds to piezo guitars. I bought my LGX-SA about a year before the RMC subfilter modded piezo boards were put on the Godins though I love the sound and feel of mine and don't have any complaints. Is the GP-10 great sounding with the Piezos?  Also is it more user friendly than the GR-55?

Elantric

The new Boss GP-10 works great with piezo guitars  no third party sub harmonic filter is needed on GP-10.

I have 4 Xtrems, the Black one suits the LGX-SA better as all the rest of the hardware is also black.

Quotedid the screw go all the way through the body?

No - I used a shorter modified strap button type screw. The guitar appears to have a factory Bigsby style tremolo, no problems. its an optical illusion due to camera angle that makes the Xtrem appear to be installed slightly "crooked"


I love the GFS Xtrems because these come with choice of two spring types in the box  ( hard or soft)  - i use the hard spring and have good sustain, without using the tremolo, I can still do country riffs and double stop string bends  - while open E or A strings remain in tune, (instead of going flat with every string bend - which is typical result when the tremolo spring is too soft. )


The Nickel Xtrem is currently on a 2013 Epiphone Wilshire  - replaced the dreadful stock "Epiphone tremotone" tremolo - and now this guitar's tone and sustain is resurrected   - I  removed it from the "ebay for sale" pile of gear.
http://www.epiphone.com/Products/Designer/Wilshire-with-Tremotone.aspx


 

Rorster

Also I forgot to ask about the tracking of the GP-10 compared to the GR-55, the tone of the GP-10... anything else as an owner you might have an opinion about.
Thanks so much as usual.
Rorster

Elantric



I love my GP-10 - now own two

The Boss GP-10 with its rapid patch changes, fastest Roland 2014 Guitar to MIDI tracking, and 4 CTL pedals or two expression pedals is night and day a better tool for my needs compared to the sluggish GR-55.

read my reviews on GP-10
https://www.vguitarforums.com/smf/index.php?topic=11506.msg85256#msg85256

July 11, 2014

After spending the past 2 hours playing the Boss GP-10 - all I can say is Wow - Wow- Wow !

( I'm in a hotel in Fullerton and in Los Angeles until Noon Saturday- PM me if you are in LA area and want to meet up this Saturday)

A few observations:

The early GP-10's I saw appeared to have identical Pantone Yellow color as 1980 Roland GR-100, while the in person the final production Boss GP-10 has a pearlescent semi metallic Yellow  color.   

Gear used for my Boss GP-10 Initial review

* 2012 Godin xtSA with RMC Piezo saddles and summer 2011 era Polydrive board.

* Planet Waves 10FT 13 pin Cable

* 2012 Apple MackBook Pro Retina w/ Logic X

* Audio-Technica ATH-M80 Headphones + USB Cable

* Galaxy Note 2 (used as MP3 player feeding GP-10 Aux Input

On Boss GP-10, I set the GK Type to "PIEZO_R" for the RMC Piezo Pus (and GK Phase = Reverse, and I assigned the GK3 S1 and S2 to COSM MODEL PU Up/Down - just like VG-99) ) on my Godin xtSA. And this thing rocks-  While there do exist occasional minor Piezo PU rumble anomalies here and there (which GK-3 users will never see ) [EDIT: since tamed by adjusting the PIEZO Low EQ Freq to -2dB) , I can report  the Boss GP-10 with GK Type set to Piezo_R' should work fine out of the box for owners of 2012 or newer Godin xtSA / LGSA / LGXT guitars

I've been going through the GP-10  factory presets - and Im struck by the clarity,dynamic range and low noise.
Its rather clear the GP-10 has the BEST DSP emulation of acoustic guitars and 12 string acoustics I ever tried. The COSM Modeling "bar has been raised to new heights in the Boss GP-10 -it has the Best Nylon model  Roland ever delivered to data ( blows away the VG-99 & GR-55  Nylon and Acoustic models)
All the above experience might be owed to the excellent RMC Pickup and Richard McClish's commitment to "'improving the breed ' in response to market demands 

Bottom line the Boss GP-10 Definitely delivers pro performance.

Many of the Boss GP-10 presets repurpose CTL 1 as a Tap Tempo, and others use CTL 2 as a Infinite Hold.

And Eureka, the Boss GP-10 makes full use of the GK-3 three way select switch ( THANK YOU Roland!)

Patch changes occur swiftly and clean, zero gaps in any audio.

I fed MP3 backing tracks to the 3.5mm Aux In and no skips  or dropouts during any Boss GP-10 patch change which are almost seamless.

I installed the Boss GP10 USB Driver on my Mac - and after USB connection the Mac "sees" the Boss GP-10  as a multichannel Core Audio Interface with Eight Input Channels and Eight Output Channels.

In Logic-X  - I assigned the GP-10 to be the Audio I/O Interface with I/O Buffer size set to 128 samples (8.8ms Roundtrip Latency ) Excellent zero problems - and very clean  24 bit audio.

I made a test recording of all patches , then I rewound, and jammed along with the prior recording  while making lots of patch changes on the GP-10  - and experienced flawless audio - no drop outs.

The GP-10 can become the central heart of  a small system  - the tone is very organic responsive and sounds very good.

I'm tempted to order a spare asap. - I love this thing! 

Other Boss GP-10 concepts worth reading

Boss GP-10 Control Expansion Options
https://www.vguitarforums.com/smf/index.php?topic=11818.0


https://www.vguitarforums.com/smf/index.php?topic=11506.275

I can use GP-10 presets#80-89 and have every tone I need for Normal guitars.

Let the other forums remain stuck in the 1990's regarding their negative opinion on COSM.

I bet if I paint my GP10 all black , suddenly other guitars players would think it sounds better and want to know what I'm playing thru.

https://www.vguitarforums.com/smf/index.php?topic=11506.msg89530#msg89530
I played accompaniment  lead guitar as a part of an acoustic  duo with a local singer songwriter.

Since this was a low volume acoustic setting in the corner of a  local restaurant with a small PA  - I was just going to use my Variax 700 Acoustic > Fender Volume /tone pedal> LR Baggs Venue DI box > PA and use the single vocal floor monitor to hear myself in the mono mix of all vocals and all guitars.

But 24 hours before the gig, my Variax 700 Acoustic "A" string piezo saddle  became intermittent and needed repair  -so at the last minute I decided i would shift gears and use my Godin LGX-SA > Boss GP-10 and use the Acoustic COSM models.

90 minutes before the gig I did a trial sound test at home with my Alesis Alpha 112A Powered speaker as this represents a similar performance characteristic of the house PA at the venue I was to be performing.

I discovered I needed to tame ground loop buzz, and I had very little time to prepare  I had an ART RDP passive DI Box laying nearby I tried that but its designed for re-amping with built in non unity gain with built in - 20db signal attenuation  (even with all its Volume controls maxed out on 10)   so I ended up using the Boss GP-10( on Line/Phones setting)  left mono out > 1/4" instrument input on LR Baggs Venue DI box and left all its EQ controls set Flat and fed its XLR out into the Powered PA cab.

I copied Factory preset #58 "GB45 Basic" (Gibson J-45 Acoustic COSM)  to the empty range of the GP-10's patch area   #92 
and I copied Factory preset #65 "MA28 Set" (Martin D-28 Acoustic COSM)  to GP-10's patch area   #93 

I figured using this strategy I would have multiple choices for  acoustic tones and I'd use the one that best fits the house mix at the gig.

I fired up Boss Tone Studio Editor and in seconds on both patches I reassigned the CTL pedal #1 to enable disable delay instead of Alt Tuning(which I did not need for this gig), I set CTL #2 to enable /disable COSM 12 string. I needed a volume pedal for swells on many tunes and originally I was going to assign the GP-10 built in expression to Volume  - but during my home sound check I discovered that both these factory GP-10 patches #57 and #65 feature a panning to normal electric guitar tones when the expression pedal is set heel down  - and was actually very happy with these COSM Amp Sim  tones using my Godin LGX-SA's Seymour Duncan humbucking pickups. I figured these tube amp tones might be helpful in the mix as the other guitarist who was  strumming using her Taylor with Fishman Piezo into the PA. Often it can be a confusing mess when there are multiple acoustics with similar tones in a mono PA, and I wanted the option for my guitar to stand apart for better clarity.

So I located my Roland EV-5 expression pedal and connected that to the GP-10 External Expression jack, and used Boss Tone Studio Editor  to map Expression pedal #2 as Volume.

I then spent the next 30 minutes adjusting the internal mixer on the GP-10  - so my Acoustic / electric guitar pan pedal had matching volume levels and click "write" for both patches  - for safety I copied patch #92 to Patch # 94 - in this manner I could start at patch # 92  (Gibson J-45) and if that proved too bright in the PA mix , I could use patch #93 (Martin D-28 Acoustic), and if I had a patch up/down pedal accident  - I had a safety copy of patch #92 at Patch #94 

At the gig that night, I ended up using  #93 (Martin D-28 Acoustic), and through the house PA I sounded just like a Martin acoustic, but for solos I ended up using the Neck PU and and the GP-10's Fender Deluxe Crunch COSM Amp sim (that was inherited from  factory patch #65)  and it sounded great -  took all of 1 minute to set up/teardown. This was a situation where a VG-99 on a chrome stand would have been a distraction to the audience since it was a very small intimate setting, My guitar sounds were great  I love the Boss GP-10, and my recent acquired 2013 Godin LGX-SA ( $600 on eBay due to a cracked headstock which was an easy fix)    - I had many compliments on my guitar tone, and we had a great gig


Rorster

Holy Moly elantric! If YOU feel that way about this unit there must a whole lot of something to it. I'll be putting my hands on one for a trial run soon. Thanks! One of the reviewers I watched on You tube said that the GP-10 has no "Banks" as many of us are used to seeing and that may be something getting used to. I suppose that means use of an editor and laptop are necessary to get the most out of it. It comes with its own editor I imagine. No big deal if it tracks good and sounds good. Not to mention the "banks" on the GR-55 are wacky anyway. Thanks again for your smokin expert advice.

Hurricane

Bare with me blood brother , I've so much catching up to do .

That's absolutely !  :D wild my admiration
I asked many about doing that mod on mine ( same cognac model ) and
was dissuaded and I let it go and thought no more , I felt like I was going
to get another one with one on it for years until just now .

A clarification on the issue of body cavity chamber discrepancies of the LGXSA
please and how you solved this issue and it's detail(s), if you could be so kind .

I've wanted a vibrato since I can remember !

HR

Elantric