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Ghost Full Kit ReviewUpdated 6 days ago

Here is an old but great review of our ghost system. It covers both the Acousti-Phonic pre-amp and the Hexpander. It is a great overview of the features, benefits, sounds, etc.


You’ve undoubtedly seen and heard piezo pickup-equipped electric guitars and maybe even checked out some guitars that feature the Graph Tech Guitar Labs Ghost System (the Carvin NS1, for example). Switching between electric guitar and acoustic guitar sounds at the flick of a switch has been a dream for a long time, and over the past five years, in particular, high-end instrument builders have really made these systems sound quite good. Unfortunately, not everyone can afford a $1,500 (or more) guitar equipped with piezo output, and “Roland-ready” guitar synth options only exist on a handful of specific models.

The folks at Graph Tech Guitar Labs have given players a great option for retrofitting their existing favorite guitars — the Ghost Modular Pickup System. This retrofit incorporates the actual piezo pickup crystal directly inside the string saddle of the guitar, opening up a whole new world of benefits, options and opportunities.

Most notably, the Ghost system enables you to not only obtain acoustic guitar tones from the piezo output, but it also (optionally) provides 13-pin hex output for use with popular guitar synth products... without an annoying “extra” pickup mounted somewhere between your magnetic bridge pickup and the bridge.

Not only does the Ghost system sound very good, but we also found that guitar synth tracking was excellent. This is one after-market modification worthy of serious consideration when looking to obtain acoustic and MIDI capabilities from your existing electric guitar.


The most prominent component of the Ghost system can be found in Graph Tech’s String Saver Saddles which contain encapsulated custom-engineered piezo crystals. As a result of replacing your existing saddles with the “Ghost” saddles, the modification is virtually invisible. Routing the lead wires from each saddle goes through your existing bridge/body and into the control cavity of the guitar (see the Usability section for more details regarding installation). Each String Saver Saddle is individually calibrated to ensure precision balance performance within each set of saddle pickups.

The Ghost Saddle Pickups deliver a natural compression comparable to that of an authentic acoustic guitar due to the encapsulation of the piezo crystals within each string saddle. As a result, playability can have a very dynamic range without overloading the input channel, whereas with many piezo pickup systems, playing with a hard attack can cause signal overload, producing an undesirable “quack” effect.

Depending on your configuration needs and application, there are a couple of different options when selecting a modular preamp for signal processing. Each preamp module is small enough to be mounted into the control cavity of your guitar without the need for additional routing. But when using the Hexpander Preamp for connecting a guitar synth controller, routing will be needed to accommodate the installation of the 13-pin output jack.

The Acousti-Phonic Modular Preamp is responsible for signal processing of the Ghost Pickup System enabling the natural acoustical sound produced by the guitar to be either amplified or routed direct to a console, without feedback or live microphone issues usually experienced with an amplified acoustic guitar.

In addition, the Acousti-Phonic preamp also features an automatic switching mechanism for mono and stereo applications. By plugging in a standard mono cable to the guitar, the Acousti-Phonic module will detect the mono cable configuration and route both the magnetic and Ghost pickup signals to the single mono cable. When using a stereo cable, the Acousti-Phonic module will split the two pickup systems, allowing one signal to be routed directly to a mixing console and the other to be routed to your guitar amplifier.

The Hexpander Preamp Module option provides MIDI output, enabling you to connect to a variety of guitar synth controllers, including the Roland GR33, Roland VG88, V-Bass, and Axon 100, to name a few. When choosing this option, you will need to install the 13-pin output jack as well.

The Graph Tech Ghost System also features an exclusive “Traktion” switch which allows the user to modify the tracking curve and optimize the hexaphonic output signal depending on your unique playing style, guitar, and controller configuration, useful for shredders dealing with MIDI tracking issues.

The Ghost Modular Pickup System also provides plug-in (solder-less) switching options providing control of magnetic, piezo, or hex outputs, or a blend of all three, providing numerous tonal possibilities. An optional momentary Up/Down mini toggle switch for use with the Hexpander Preamp module enables control of the MIDI program change function of the synth controller.

Other control options include:

A Mid Boost switch consisting of a two-way mini toggle that chooses between the original Ghost output curve or mid boost, fixed EQ setting.

A Push/Push Mid Boost volume control consisting of a two-position push/push switch and volume control dedicated to the original Ghost output curve or a mid boost, fixed EQ setting of the acoustic piezo volume output signal.

A nine-volt battery supply is needed when installing the Acousti-Phonic or Hexpander Preamp module unless connecting to a synth controller (via the 13-pin output jack) that provides direct power to the guitar.

Graph Tech Guitar Labs offers a variety of options in customized pre-assembled kits to suit your particular need and application. Or, you may order components individually to enhance features that may already be installed on your guitar.

The Ghost pickup system is retrofitable to most Strat, Tele, Wilkinson, Tune-o-matic, PRS, and P/J-Bass bridges. Graph Tech offers a full catalog of components and pricing via their website. If you have a traditional electric guitar with only magnetic pickup output, if you’re going to go through the trouble of modifying the instrument, we suggest installing most of the options for both acoustic piezo output as well as the 13-pin MIDI output with control switches on your guitar unless you are certain that you’ll never have any interest in playing guitar synth.


Our test guitar, courtesy of Graph Tech Guitar Labs, came equipped with a full installation of all possible features, enabling us to get an idea of how it all works. Having regularly used other types of piezo and hex-equipped products, the Ghost Modular Pickup System is an excellent alternative when considering retrofitting one of your guitars.

Starting at the first point of contact between guitar string and piezo pickup, the Graph Tech String Saver Saddles (encapsulating the piezo crystal) are designed out of a polymer which, unlike a standard metal string saddle, is topped by a thin Teflon coating on top of which the guitar string vibrates and moves freely. Unlike strings being held fast by a traditional metal saddle, this eliminates the single fine point of contact between the string and saddle and replaces it with a longer, smoother track to support the string.

We didn’t actually perform an installation ourselves, but from reviewing the installation video provided on Graph Tech’s website, someone with basic guitar modification skills and know-how could perform this upgrade as easily as changing pickups, adding switches, and doing some minor body routing. However, if you haven’t had experience rebuilding your guitars, we suggest you take it to a professional for installation.

Regarding the installation of the piezo-equipped String Saver Saddles, you will need to route the fine lead wires from the bottom of each saddle to the preamp module, which will most likely be located in the control cavity of the guitar. Depending on the type of guitar and bridge you are modifying, a certain amount of drilling may be necessary for this procedure. On the test guitar reviewed (an inexpensive Strat clone), we really had to look hard in order to see where the routing holes were located and where the wires were routed – it was virtually a “Ghost” in itself.

The Acousti-Phonic preamp proved easy to use as well. When connecting a standard 1/4” mono guitar cable, the preamp automatically sends both magnetic and piezo signals to the same output source. The on-board “Quickswitch” provided an easy selection of individual and/or blended sounds between the magnetic and piezo pickups. In addition, the separate volume control for the piezo and magnetic pickups allowed us to get a specific blend between each pickup to meet our personal preferences.

When connecting a ¼” stereo guitar cable, the Acousti-Phonic preamp automatically detected the stereo configuration and splits the signal to allow for separation of piezo signal and magnetic signal to two different destinations – for instance, the piezo signal going direct to a mixing console and the magnetic signal going direct to our guitar amplifier

Moving on to the Hexpander preamp module section of this setup, the Ghost system provided the same comparable switching features of a Roland GK hex pickup system. The demo model guitar we reviewed came fully equipped with the 13-pin output jack and “Quickswitch” mini toggles, which control the blending options between MIDI, MIDI/Magnetic, and Magnetic Only signals. Also provided was a mini toggle that made the program Up/Down selection with our synth controller a breeze.

We connected the Ghost-equipped guitar directly to a Roland GR-33 guitar synth via the on-board 13-pin output jack. The Hexpander preamp module performed amazingly well. By comparison to other after-market hex pickups, the Ghost System provided outstanding tracking capabilities, presumably due to the guitar string having direct contact with the piezo-encapsulated string saddle.

Playing was a breeze through fast runs, hot licks, lush arpeggios, and more — the tracking was fantastic.The Ghost system eliminated the usual issues experienced with standard surface-mounted hex pickups found on the market today, and not having bulky ad-ons sitting on the guitar body was truly a pleasure.


As far as sound quality is concerned, we detected what we perceived to be a slight difference in tone quality by comparison to a guitar with standard metal saddles. The String Saver Saddles seemed to provide a more full-bodied tone (on our Strat copy), and Graph Tech claims they increase sustain by 25% over a brass saddle, though we didn’t detect any specific additional sustain without having an unmodified guitar for comparison.

Our Graph Tech Guitar Labs test guitar came fully loaded with all the Ghost Modular Pickup System options, and they performed exactly as described in the literature. Having played other electric guitars fitted with a piezo pickup, the piezo-encapsulated saddles provided the same type of acoustical voice we’ve come to enjoy from other high-end instruments. The piezos captured all the characteristics of a live acoustic guitar, plus some added benefits too!

The most beneficial characteristic of the Ghost system is that as a result of the piezo crystal being encapsulated in the string saddle itself, it produced a consistently clear and vibrant sound without signal overload (often referred to as “quack”) regardless of how hard an attack was used when playing.

Documentation and Product Support

Though we did not receive any documentation on the test model guitar for its installed options, we found Graph Tech’s website to contain quite a bit of information regarding material specifications, installation, and applications.

We particularly enjoyed viewing the installation video to get an idea of what the project might entail — installation should really be a straightforward affair for anyone comfortable with guitar maintenance and modification. The long list of FAQs also answered any additional questions we had. To add a personal touch, Graph Tech provided all contact information accompanied by a picture of each representative to put a face with the name – you’ll even find direct contact information for Graph Tech Guitar Labs President Dave Dunwoodie.


Graph Tech Guitar Labs offers a number of different kits to select from depending on your needs. The retail price for including all the options (saddles, Acousti-phonic preamp, Hexpander preamp, two Quickswitches, a momentary Up/Down program select switch, mid/dark Push/Pull volume pot, MIDI/Hex volume, and all wiring harnesses) will run under $650.00 – a good price when you factor in top-quality acoustic sounds and a great-tracking on-board MIDI controller.

Keep in mind that if you aren’t comfortable performing modifications and installation yourself, you will need to factor in the cost of having a tech perform the installation. The service should only take a few hours of time.

Check out the full article here!

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