Tech Tips & FAQs


1. Combining the Acoustic Matrix and Rare Earth pickups

Did you know that you can combine the Acoustic Matrix active undersaddle pickup with the Rare Earth series of active magnetic soundhole pickups to create a new dimension in sound? This combination allows you to power both active systems from a single 9-volt battery and results in a T-R-S (Tip-Ring-Sleeve) output. The Acoustic Matrix signal on the tip of a stereo jack, and the Rare Earth signal on the ring, will allow you to send both signals simultaneously to separate amps, or channels in a mixer, to create your own acoustic sound. This modification requires the new Switchjack Equipped version of either the Acoustic Matrix Natural 1 or Natural 2 and any Rare Earth model pickup. We would be happy to email the wiring schematics for this modification, or you can simply check it out in the Wiring Diagram section of our website.

2. Adjusting Phase settings on the Acoustic, Bass and Pocket Blenders

Many players have questions regarding the correct way to set the Phase buttons on the external Blenders. An easy way to achieve the correct Phase setting is to start with the mic signal only. Listen as you switch back and forth with the mic Phase button. One setting will give you a fuller, richer sounding signal with a little more bass response than the other position. This will be your in-phase switch position. You then simply set the pickup channel the same as the mic. If the button is in the Out position on the mic channel, it should be Out on the pickup channel. Playing in-phase will allow you to get a richer, more feedback-resistant natural sound from your instrument.

3. Adjusting the microphone level on the Prefix Stereo Blender

There are frequent questions about controlling the balance between the undersaddle pickup and the microphone level when using the Prefix Stereo Blender. Balanced output levels between the microphone and pickup will allow greater control over your sound. We have provided a trim control potentiometer on the underside of the preamp to better enable you to balance these signals. To adjust the microphone signal, set the BLEND slider to the center position and, with a small screwdriver, adjust the potentiometer until both the microphone and pickup levels are balanced.

4. Adding an internal connector to the Rare Earth series pickups

We occasionally receive requests for a method to permanently mount the Rare Earth series pickup in a guitar, while maintaining the ability to remove it when needed. This is possible by placing a connector in-line between the pickup and the endpin jack. We do not provide the parts, but we suggest using a high-quality shielded stereo connector*, which can be secured inside the instrument. Make sure that all solder connections are precise and shielded for optimum audio quality. Once the connector is installed, you can easily unplug the pickup when it is not needed. This modification also makes it possible to use a single Rare Earth pickup on multiple instruments.

*The Rare Earth Mic Blend (introduced in 2017) is wired with the ability to blend the mic and pickup using a stereo cable. A high-quality shielded 4-conductor connector is needed to modify the Rare Earth Mic Blend for temporary removal while maintaining the ability to blend outboard. Fishman does not provide this part.

5. Will the Powerchip allow me to blend my Powerbridge and magnetic signals onboard the guitar?

The answer to this is yes and no. The function of the Powerchip is to buffer the Powerbridge signal to better match up with the magnetic output. This impedance matching allows the Powerbridge and magnetic signals to be mixed to a mono or stereo output, depending on the cable used. A mono cable will give you a combined piezo/magnetic signal to the tip of the output jack, and a stereo cable will give you the magnetic signal on the tip and the Powerbridge on the ring. The Powerchip is not a blend pot, but a volume pot for the Powerbridge only. To adjust the amount of blended Powerbridge and magnetic signals, the Powerchip and the original magnetic volume controls must both be used.

6. Alternate BP-100 installation

If you have lost a Felted U-Clip that comes with your BP-100, there is an alternate method of attaching the pickup to your bass bridge. Since the U-Clips can be a tough item to locate at your local Fishman dealer, you can use a standard hot-melt glue gun and glue stick as a temporary or even permanent solution. Make sure you have a nice flat surface area on the bridge to affix the pickup. A sanding block is the best tool for this. Once the area is sanded flat, apply a liberal amount of hot-melt glue to the back side of each element and affix to the bridge. Remove any excess glue and use a clothes pin (or the remaining U-Clip) to hold it in place until it dries. Once dry, you’re all set. To remove the pickup, just heat it up slightly with your average blow dryer and it will come right off.

7. Using the Powerchip on an Archtop Guitar

We have periodically been asked to suggest a way to blend the Fishman Archtop Piezo replacement bridge signal with an existing magnetic pickup on an Archtop guitar. We have found the Powerchip to be an excellent solution to this problem. The Powerchip was initially designed to allow onboard blending of magnetic pickups with our Powerbridge Electric Guitar Piezo Bridge. It will also work on the Archtop and other similar blend situations. Two things to remember are: the Powerchip volume pot acts only as volume control for the piezo bridge. It is not a blend pot (See tech tip #5 for details on Powerchip operation and output scenarios). Secondly, you must have access to a 9-volt battery which is needed to power the Powerchip. Once installed, you’ll have the option of a mono mixed signal or a stereo T-R-S signal from the instrument. The Powerchip is a diverse product that can open up audio possibilities in many instruments.

8. Tune-o-matic Powerbridge Pickup tips Now that our Tune-o-matic Powerbridge pickup is online, here are a few things to consider before getting started.

Nashville vs. ABR-1 format
The Tune-o-matic Powerbridge conforms to the footprint of Gibson’s Nashville-style bridge. If you are replacing an old style ABR-1 Bridge with a Powerbridge, ask your repair-person to plug and re-drill the post-holes on the guitar’ top to fit the hardware and hole spacing for the Nashville bridge.

Long-Shaft Powerchip
We are now offering a special Powerchip with the correct shaft length, specifically for Les Paul® Tune-o-matic Powerbridge users. The potentiometer for this Powerchip will retrofit perfectly into Les Paul models with long-shaft volume and tone controls.

What modifications are required?
The Tune-o-matic Powerbridge Pickup can install without any major modification to a Les Paul. You will have to file a small notch in the pickup-mounting ring to route the Powerbridge wire. If you want to keep the cosmetics of the guitar absolutely untouched, we suggest that you purchase a new pickup-mounting ring to replace the original.

9. Choosing between the Acoustic Matrix Natural I or II

We offer our Acoustic Matrix Active Undersaddle Pickups with two preamp voicings, the Natural I and Natural II. These 2 preamps will accommodate different instruments and playing environments. This quick overview will help you choose the correct version for your guitar.

Natural I
Choose the Natural I if you want more bass response than the guitar naturally produces. Typically, the Natural I is a good match for players with non-scallop braced instruments (especially smaller sizes), who perform solo or in small all-acoustic ensembles at relatively low volumes. If your instrument is at all prone to feedback, you may want to check out the Natural II.

Natural II
This version is designed for instruments with lots of naturally deep bass such as a big scallop-braced dreadnought. Also, if you play in a band with an amplified rhythm section, the Natural II will cut through. Because of its ability to reject low-frequency feedback, the Natural II is the choice of touring performers who play large venues. With the correct version of the Acoustic Matrix pickup system in your guitar, playing feedback-free and with great tone is as easy as plugging in.

10. Why don't any of our preamps have a pilot light?

We made a deliberate decision many years ago to not include a pilot light on any of our battery-powered electronics. Most importantly, a pilot light (LED) will unnecessarily reduce the life expectancy of a battery. Since we want to guarantee you every possible hour of use from each battery, a pilot light would be wasteful, which is also why we feature a Low Battery (and/or) Clip warning LED on many of our products. We include warning lights so that you’ll know ahead of time if you’re about to get into trouble. Our Low Battery LED Is triggered to activate with about 1 hour of battery life remaining. Our Clip light blinks when your pickup overloads the preamp and is telling you to trim down the preamp input.

11. Can my Acoustic Matrix pickup element be cut to fit any length slot?

The Acoustic Matrix undersaddle pickup element comes in a standard length of 2.650″ (67.3 mm), with a sensing area of 2.500″ (66.55 mm), which will fit into 99% of the acoustic guitar saddle slots and string spacings that exist today. For custom length slots, we are happy to manufacture pickups on a special order basis. Due to the nature of the manufacturing process, the Acoustic Matrix pickup cannot be cut to fit once it is made. Saddle slots over 3 inches can be accommodated with a 2-piece saddle, as we cannot manufacture a 1-piece pickup over 3 inches in length. Please see your local Fishman dealer for pricing and ordering information.

12. How much wood can be taken off the top of the Mandolin and Archtop replacement bridges for fitting and intonation adjustment?

We recommend removing no more than 5/32″ of material when fitting either of these bridges to your instrument. There are two reasons for this: The string volume may be uneven and unpredictable if the strings end up too close to the embedded pickup element. Secondly, removing too much material can weaken the upper part of the bridge, and may cause structural damage when under proper string tension. As always, we recommend professional installation for these products whenever possible.

13. Which Rare Earth Pickup is best for me?

With the addition of the new Passive Rare Earth soundhole pickup, the Neo-D, there are now more choices than ever to get a great sound from our Rare Earth series. This Tech Tip will run down the options for you. The Neo-D is a lower-cost alternative, requiring no batteries or additional cables. It is a passive, single-coil magnetic pickup that comes equipped with a low-capacitant cable with a 1/4″ plug. The Active Rare Earth series consists of:
• The Single Coil, which features a brilliant cut-through tone.
• The Humbucker, which features a noiseless signal and richer tone.
• The Rare Earth Blend or Custom Blend, which allows players to combine an active magnetic tone with the sound of a high-quality condenser mic.

All the active Rare Earth pickups come with our Switchjack stereo endpin jack, which can be used hanging out of the soundhole, or installed as a permanent endpin jack with strap button. Rare Earth pickups are also available in left-handed models.

14. Can the Pro-EQ Platinum Bass be used with an electric bass?

Absolutely. The new Pro-EQ Platinum Bass preamp/DI was designed for any bass, acoustic or electric. In fact, the Platinum Bass was beta-tested by some of the world’s finest electric bassists — receiving a resounding thumbs up from all. If you play bass, acoustic or electric, then this is the preamp for you. With an unmatched feature set and exceptional tone shaping, this product will enhance any electric bass signal.

15. After having an Acoustic Matrix pickup system installed in my guitar, I am noticing that some strings are louder than others. Is there something wrong with this pickup? How can this problem be solved?

It is virtually impossible for an Acoustic Matrix pickup to be more responsive in some areas and less responsive in others due to a defect in the pickup. The reason for unbalanced string volumes is a lack of even down-bearing pressure on the pickup under the weaker strings. This translates to lower volume for that particular string. This problem can be caused by many things, including: an uneven saddle slot, a saddle with an uneven bottom surface, a guitar that is “belly-up,” a lifting or loose bridge, poor fit of the pickup in the saddle slot, and an insufficient break angle of the strings over the saddle. A qualified repair shop should be able to identify which issue or issues you are dealing with and make the appropriate corrections.

16. Can the Resophonic pickup be used with my biscuit style resonator?

We’ve had a lot of questions regarding the use of this product with both biscuit and spider-type resonators. The good news is that it will work with both and comes with complete mounting instructions for either type of resonator. You can also install it passively or with an onboard endpin mounted preamp for a boosted and buffered active signal. The resophonic pickup is a great, practical alternative to microphones when amplifying a resonator.

17. Whats the Difference between the Martin Gold Plus and the Acoustic Matrix?

In a previous Tech Tip (see Tech Tip #10), we discussed how to choose the correct Acoustic Matrix system for your guitar. The differences between the Natural 1 and the Natural 2 were explained in detail to help you make the correct choice for your instrument. Here, we will answer a common question about the Martin Gold Plus. The Martin Guitar Co. has been a great friend and business partner with Fishman for many years. They market and sell many Fishman products under the Martin Brand name. In the case of the Acoustic Matrix, the name Gold Plus is used. The Martin Gold Plus is the Acoustic Matrix Natural 1, narrow format 3/32″, and the Martin Gold Plus Max is the Acoustic Matrix Natural 2, narrow format 3/32″. No tricks, no gimmicks, just the same quality components with different names. The Fishman version also offers the option of a wide format, 1/8″ pickup for wider saddle slots.

18. The SBT Soundboard Transducer - A new twist on pickup/microphone or dual Pickup combinations

For years now, one of our more popular pickup combinations has been the Acoustic Matrix Natural 1 or 2 active undersaddle pickup along with the Crown GLM-200 mini condenser mic run through our Pocket Blender. A new configuration that is gaining popularity is to replace the microphone with our SBT Soundboard Transducer.
When attached to your instrument’s soundboard, the SBT can provide a full and natural response that can be very effective when mixed with an undersaddle or even a magnetic pickup. The SBT is also an economical choice for a second source pickup. The SBT can also be a very effective main signal source when combined with the Crown GLM-200. Whether you are using the Pocket Blender or another mixer to combine signals, the choices are getting more interesting for dual-pickup combinations.

19. Whats the best position to mount the Full Circle Upright Bass Pickup?

Our Full Circle upright bass pickup is encased within a height adjuster wheel. The post that holds the wheel in place is threaded (for precise adjustment) on one side, and is not threaded on the other. We’ve had many people ask if there is a tonal difference between threads up and threads down mounting position. The answer is yes, there is a subtle difference, but you should get satisfactory results either way.
Mount the Full Circle threads down, and the hot side of the pickup faces the strings. This translates to more defined articulation and attack, with a slight emphasis on string sound. When mounted threads up, the hot side of the pickup faces the body of the bass. You’ll get a more wooden acoustic tone this way, with a more rounded attack and less edge. Which way is better? Our local bass repairman tells us that most of his customers prefer the sound of the pickup in the threads up position.

20. Adding a passive volume pot to a Fishman Powerbridge

If you already have a Fishman Powerbridge on your guitar, you may also have one of the original 5-meg passive volume pots that was included with the bridge. We no longer provide the 5-meg pot with our Powerbridge pickups, but we now include a diagram to upgrade the performance of your Powerbridge with a standard 250k pot.
We feel that this is a better option, and are now making this modification available in the installation instructions included with the Powerbridge pickup. This passive circuit has a smoother taper and more even response than its 5-meg predecessor. It will attenuate the Powerbridge to match up better with magnetic pickup levels. Components for this circuit can be easily found at any electronic parts retailer.

21. Adding a Rare Earth to a guitar with an onboard preamp/EQ

This Tech Tip will explain adding a Rare Earth Active Magnetic soundhole pickup to any guitar with a mono output onboard Preamp/EQ. You will not be able to control the Rare Earth with the onboard preamp, but it will give you the Rare Earth signal on one terminal of the stereo jack. You can choose whether to add the Rare Earth to the ring, or give it the primary tip position. You will be able to access both pickups with a stereo Y cable, or choose just the tip terminal pickup by using a standard cable. This modification is not possible with systems that have an existing T-R-S stereo output, such as the Prefix Stereo Blender.

22. My Acoustic Matrix pickup is balanced and sounds great, but Im noticing a hum that sometimes disappears. I can make the hum disappear when I touch the endpin jack. Is this an electronic problem?

A humming pickup is almost never the result of an electronic problem, but rather the result of issues surrounding the installation of the pickup in the saddle slot. The most common reason for this problem is a tear or rip in the foil wrap of the pickup. This material is the shield of the pickup, and when disturbed will cause the pickup to hum. Another reason for hum is a poor fit of the pickup or saddle in the saddle slot. The Acoustic Matrix pickup grounds properly when under correct pressure in the saddle slot. Anything that may impede the pickup from being properly compressed in the slot, can be a cause for hum. You should be sure that the pickup drops easily into the saddle slot. It should not be forced into a tight slot. Also, be sure that the saddle slides easily into the slot while not being too loose. Because the bridge is made of wood, it will expand and contract in response to changing humidity levels and temperatures. This movement can affect the pickup and saddle fit, which can result in the hum being intermittent. While this is the most difficult type of hum to correct, with a proper fit of pickup and saddle, it should be a rare occurrence.

23. What is the best way to add a volume and tone control to an Acoustic Matrix active undersaddle pickup?

The Fishman VTB volume, treble and bass circuit was designed specifically for this application. This circuit has a discreet shoulder-mounted installation profile with three control pots. One is a dedicated volume pot, and the others are concentrically-mounted treble and bass pots. This controller not only gives you fingertip control of your volume, but also the ability to boost or cut treble and bass frequencies to dial-in your tone. It works well with either the Natural I or Natural II Matrix systems, as well as the Martin Gold Plus and Powerjack. This item can be purchased through any local Fishman retail dealer.

24. I did not receive Aura software or a USB cable with the factory-installed Aura on my new guitar. How do I get these items to use the software?

In the case of an OEM Aura, installed at the factory, we have created images from that exact guitar model, and the manufacturer (along with Fishman), has selected the best matches to include on your guitar’s Aura device. Because there are no better images to be gained, these factory images cannot be edited. So, the factory installation of your Aura product is already optimized for your guitar. For more information on how Aura technology works, see the Aura’s product page.

25. Fishman’s list of Aura Images includes guitars, mandolins and other instruments. Does that mean I can use an Aura pedal to make my guitar sound like a mandolin?

No, because Aura is not modelling, it’s imaging.
To create Aura images, we record an instrument (as an example, a dreadnought 6-string acoustic) with several different microphones and the guitar’s Matrix Undersaddle pickup, all at the same time. Each microphone output is compared to the pickup output using Aura algorithms, which identify the differences between the pickup sound and the microphone sound. This data is used to create the Aura images. If you play the dreadnought with the Matrix Undersaddle through an Aura device with a specific image loaded, the Aura is able to recreate the sound of the high-quality studio microphone, using only the pickup signal. If you plug in a different guitar (a nylon string, for example) using the dreadnought Aura images, ther nylon string guitar would not sound like a dreadnought guitar — it would just sound bad.
To find the correct and most sonorous Aura images for your guitar, we have created the Aura image library and desktop software. In conjunction with your Aura device, you can search and download images that match your particular instrument. By their very nature, many of these Aura images are generalized. Players looking for exact images of guitar and microphone combinations can take advantage of the Aura custom shop, which can be contacted at auracustom@fishman.com

26. I see I can get a Matrix outfitted Fishman system for my guitar in Wide, Narrow or Split formats. Which do I need?

This designation refers to the width of the saddle slot. Some companies, like Martin, have traditionally used a 3/32” saddle slot, which we call “narrow”. Others, like Gibson, use a 1/8” slot, which we call “wide”. Split format is for less common instruments made by some companies, such as Lowden, which feature two saddles: a short one for the E and B strings, and a longer one for the remaining four strings. If you are unsure which model you need, measure your saddle carefully using calipers, or simply show your guitar to your installer. They will usually be able to see right away which size will fit your instrument. If there is any doubt, a “narrow” pickup can fit in a “wide” pickup slot and work reasonably well, but the reverse is not true.