PZ-Di Front Picture
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  • "Whether I am playing live or recording in the studio, the Radial PZ-DI makes my bass sound as fresh as a daisy!!"

    Ron Carter - Bass Player
    (Miles Davis Quintet, Tony Williams Lifetime, V.S.O.P., Classical Jazz Quartet, New York Jazz Quartet)
    Ron Carter
  • "The Radial PZ-DI everything you need to address piezos, solves many of the common problems and has given me solutions that open up creative possibilities. I will be using it a whole lot."

    Bil VornDick - Producer
    (Marty Robbins, Alison Krauss, Bob Dylan, Bela Fleck, Jerry Douglas, T.Bone Burnett and Mark O'Connor)
    Bil VornDick
  • "With the PZDI, we were able to integrate multiple piezoelectric devices seamlessly and with glorious results. Radial has once again proven they are a cut above the rest."

    Brad Madix
    (Rush, Shakira, Marilyn Manson, Def Leppard)
    Brad Madix
  • "The Radial PZ-DI is the perfect complement to my bass. I finally found the DI that I was looking for."

    Carlos Puerto - Bassist
    (Chick Corea, David Sanborn, Chris Botti, Herbie Hancock, Stevie Wonder, Ricky Martin)
    Carlos Puerto
  • "I use the PZ DI for guitar or banjo. It is very friendly to those instruments. Basically clean and fat and the sound guys have lots of good round signal to tweak."

    Tim O'Brien - Acoustic Guitar and Banjo
    (Mark Knopfler, Alison Krauss, Steve Earl, Garth Brooks, Dwight Yoakam; Garth Brooks)
    Tim O'Brien
  • "Using the PZ-DI has brought new depth and transparency to bass and guitar that play in the body of the Boston Pops Orchestra. Our tried and true arrangements never sounded so good."

    Steve Colby - FOH Engineer
    (Boston Pops Orchestra)
    Steve Colby
Thanks Radial! Matching ultra high impedance transducers to audio inputs is no longer a combination of wishful thinking and blind luck. With the PZDI, we were able to integrate multiple piezoelectric devices seamlessly and with glorious results. Anyone who is just plugging a PZ transducer into any random DI and hoping for the best is probably missing out on much better tonality and dynamic range. It's nice that there are passionate designers and engineers out there paying attention to these details. Radial has once again proven they are a cut above the rest.
Brad Madix (FOH Engineer Rush, Shakira, Marilyn Manson, Def Leppard)
Hello acoustic bass players. I purchased a Radial PZ-DI from KJR last month and simply put, I couldn't be more happy with this new piece of gear. I have struggled for years to find a pickup setup that makes my bass sound natural when amplified via the PA system. I have an Acoustic Image amp which sounds great on stage, but have never like the sound of my bass though a DI. I have been using a Fishman Platinum Pro preamp and sending the preamp DI out to the board. I'll save you the long explanation, but simply said the PZ-DI is cleaner, has a better dynamic range, is less colored, and gets rid of the ugly thump that I experience with the Fishman. My Fishman is going into retirement. I will use my PZ-DI for my feed to the PA and I will use the PZ-DI thru to plug into my Acoustic Image.

I have tried the PZ-DI with both my upright basses (fully carved bass with a Realist pickup and my 54 Kay with a Full Circle pickup). Both sound way better than with my other DIs. I don't have to apply any large EQ changes to get the sound right. A small cut at 500hz and the bass sounds like a bass (which is good unless you like the 1960s Dan Electro bass sound that most pickup/preamps produce). The 10Meg input impedance is a perfect match for piezo pickups and brings out the true bottom end of the bass.

I also tried the PZ-DI with my electric basses (Steinberger L2, 1970s P Bass, and Musicman). All of these sound really good as well. You can play with the input impedance to get slightly different sounds. The Lo Cut and Hi Cut work as advertised. I have not tried the PZ-DI on acoustic guitar, but the Lo Cut will be very useful to remove any bleed from the other onstage low frequency instruments (bass, kick, etc). I also ran my Yamaha DX7II though the box and tested the 15DB pad. Works great.

So, if you are an acoustic bass player I highly recommend that you check out the Radial PZ-DI. It is one of the best equipment purchases I have made in a long time.
Rob Rainwater

Radial PZ-DI™ Orchestral Instrument DI

Part No. R800 3005

  • Optimized for orchestral instruments on a live stage
  • Adjustable load for piezo and magnetic pickups
  • Variable low-cut filter to control bass resonance
  • 48V phantom powered, does not require batteries

The Radial PZ-DI™ is a unique direct box that is specifically designed for acoustic and orchestral instruments. Unlike most direct boxes that are limited to a 'one size fits all' design, the PZ-DI lets you properly match the input impedance to the source to optimize the frequency response, dynamics and feel so that no matter what type of pickup you employ, you will enjoy smoother, more musically pleasing results.

The design begins with a 3-position load adjustment switch: The 1 meg-ohm position delivers the classic impedance found on most active DI boxes. The 220k-ohm setting warms up the tone of a magnetic pickup to give you the feel and tone as if connected to a tube amplifier. The ultra-high 10 meg-ohm impedance is used to compensate for the harsh, squawky tone that usually plagues piezo-equipped instruments. This is followed by a fully variable high-pass filter that lets you 'size the instrument' by gently rolling off bass frequencies to eliminate unwanted resonance. You could for instance, retain the low frequencies on a cello or increase the cut-off point to better suit a violin. For active instruments such as acoustic guitars that incorporate a battery powered preamp, you can engage a low-pass filter to gently soften the hard edge for a smoother more natural tone.

To maximize signal handling and reduce distortion, the PZ-DI incorporates an innovative DC to DC switching supply that converts the phantom power to deliver extra headroom. This provides ample dynamic range for acoustic instruments. Should an extra loud source such as an active bass or digital keyboard be encountered, simply activate the -15dB pad to satisfy the situation. Other problem solvers include a 180° polarity reverse switch to tame hot spots on stage that can cause feedback and a ground lift switch to help eliminate hum and buzz caused by ground loops.

The Radial PZ-DI is a ground breaking direct box that can instantly adapt to all types of pickups so that you can enjoy the full frequency response and dynamics of an orchestral string instrument, smooth-out the peaks of bluegrass fiddle, banjo or mandolin, split off a bass guitar without excessive loading, or naturally amplify an acoustic guitar without the usual tone-altering effects.

Rob Rainwater

The PZ-DI in the real world.
"Hello acoustic bass players I purchased a Radial PZ-DI from KJR last month and simply put, I couldn't be more happy with this new piece of gear. I have struggled for years to find a pickup setup that makes my bass sound natural when amplified via the PA system."
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Active Super Direct Box


Tube Direct Box


Flange Mount Adaptors

PZ-DI™ - Applications
Using the PZ-DI with a piezo

Piezo pickups often sound harsh and unnatural. The PZ-DI solves the problem with a 10 meg-ohm input impedance that extends the frequency response and smoothes out the peaky edges. Adjust the low-cut filter to size the instrument and reduce unwanted resonance.

(click on images to view larger)

Using the PZ-DI with active acoustics

The convenience of a built-in pickup and battery powered preamp makes it easy to plug-in and play. But with less than ideal electronics, these instruments end to sound brittle and unnatural. The PZ-DI helps with a low-pass filter that gently smoothes the top end plus a variable low-cut filter to eliminate resonance.

Using the PZ-DI with a magnetic pickup

Optimize the tone of the bass by setting the load to 220k-ohm. This produces a warmer tone and natural feel that is particularly useful when recording or when preparing to Reamp. When touring with low-output vintage instruments, set the impedance to 1 meg-ohm to reduce the load.