Free Shipping on all orders!
We are fully open and shipping orders!
Free 2-Day Shipping on 90% of our orders!
30-Day - No Hassle - Easy Returns!

Radial StageBug SB-4 Piezo Compact Active Piezo Pickup DI Direct Box

Loading ...
This item is Sold Out!
Free -Day Shipping
Only Left!
Preorder Today
More on the Way
Get it by
if you order within
Get it  if you order in   Price:
Get Faster Shipping!
Shipping to a different Zip Code?
Check the delivery time for another location!
Call to order!


Product Details

The Radial StageBug SB-4 is a compact active direct box that has been optimized for use with piezo transducers. This enables violin, dobro, mandolin, cello, upright bass and other instruments that are best amplified using a piezo to be connected without compromising the tone or frequency response.The design begins with a 1/4" input for the instrument pickup. Unlike typical direct boxes that have a 1meg-ohm input impedance, the SB-4 features a very high 10meg-ohm impedance that smoothes out troublesome peaks that give piezos a bad name. The higher impedance also broadens the frequency response for a more natural and pleasing sound. The active circuit performs the high-to-low impedance conversion and balances the signal to enable long runs upwards to 100 meters without loss, delivering spectacular linearity and low distortion throughout the audio range.To help eliminate feedback on stage, the SB-4 is equipped with a high-pass filter and 180* polarity reverse switch. The high pass filter eliminates excessive bottom end which in turn reduces resonance that can cause the top of the instrument to vibrate. The 180 polarity reverse helps reduce acoustic hot spots on stage by changing the phase relationship between the PA system and room acoustics which can combine at certain frequencies to create peaks. Reversing the polarity eliminates the acoustic peak without resorting to severe equalization which only serves to compromise the natural tone of the instrument. Connections include an AUX out for a stage amplifier plus a standard XLR output to feed the PA. Power is derived from the console's 48V phantom, thus eliminating the need for batteries or external supply. One simply connects, turns on the phantom power and plays.These features combined with the compact size make the StageBug SB-4 the perfect companion for orchestral artists, blue grass players and pop string quartets that need to turn it up when in concert.


Using the SB-4 on classical guitarConnect your piezo pickup directly to the StageBug SB-4 to get the best tone. No preamp is required! Activate the low-pass filter to eliminate resonance and you are set to go. The SB-4 balances the signal for long runs and smoothes out the peaks for a more natural sounding concert guitar!Using the SB-4 on dobroUse the SB-4 with a piezo on your resonator guitar to capture the unique sound of the body. Connect the AUX out to a stage amp if you like and then send the signal to the PA. The SB-4 will help eliminate the mid range squawk and frequency peaks that often force the sound engineer to turn you down in the mix.Using the SB-4 on uprightTraveling with an upright is expensive! So reducing the size of the ancillary equipment is important. The super compact SB-4 connects from the piezo pickup to the PA and you do not need a preamp in between. The SB-4 delivers a deeper bass and more natural top end, greatly improving your tone through the PA.


As odd as it may sound, ever since the very first piezo transducers were introduced by Barcus-Berry in the 1960s, there have been concerns with respect to their performance. The primary concern has to do with the tone in that musicians and engineers constantly complain that the frequency response is peaky, dynamic response inconsistent and the instrument lacks natural warmth.Since the introduction of the Radial PZ-Pre, they have come to understand some of the challenges and discovered that the problem is not so much the transducer, but the interface between the transducer and the PA system. Piezo electric elements sound best when they are connected to a very high input impedance, but the higher the impedance, the more noise you get.Think of it this way, as you increase the impedance (or resistance) of a buffer (or amplifier) less signal will pass through. With less signal, you have to increase the magnitude of the amplification to make up for it. As with all amplifiers, the quality differs greatly. Chip based amplifiers that are incredibly efficient tend to not sound very musical. Great sounding amplifiers such as a well designed class-A circuit sound great but are much more susceptible to noise. It is the careful balance between a class-A input buffer and the selective use of operational amplifiers (Op-Amps) that makes Radial products stand out. And this is why some of the world's most renowned artists use the PZ-Pre, PZ-Deluxe and PZ-DI for their piezo instruments.The StageBug SB-4 Piezo is essentially a cut down version that enables the average musician to carry his own personal direct box to a gig and get the quality and performance that has made Radial the leader in instrument to pro-audio interfaces.

Using The StageBug SB-4

The following describes how to use the SB-4 Piezo with a standard PA system.Making ConnectionsThe StageBug SB-4 is a direct box designed specifically for piezo equipped instruments. These are commonly used on acoustic guitars, upright bass, violin and classical guitar. The intent with the SB-4 is to bypass any electronics (audio buffers) so that the piezo connects directly to the direct box and the signal is sent directly to a PA system via a microphone input channel.Before making any connections, ensure all audio levels are turned down or equipment is turned off. This will help avoid plug-in transients that could damage more sensitive equipment such as tweeters.The SB-4 Piezo is equipped with two 1/4" jacks and an XLR. The input jack is used to connect the instrument and the thru-put can be used to feed your on-stage amp or tuner. The XLR is used to connect to the PA system and for powering the SB-4's active circuit. Power comes from the mixer in the form of a 48V DC current known as phantom power. This handy invention enables the audio in the form of alternating current (AC) to be sent to the mixer at the same time as the 48V DC is sent from the mixer to the SB-4 using the same 3 conductor cable.Once connected, slowly turn the levels up to a comfortable listening level. It is a good idea to test at low volumes as this helps prevent connection pops that can damage components should something not be quite right.Using the high-pass filterWhen amplifying an instrument through a PA system, low frequency resonant feedback is often encountered. This is usually due to low frequencies from the PA system that cause the instrument to vibrate. The high pass filter is essentially a bass-cut switch that reduces the low frequency output from the instrument. If you hear low frequency resonance, push it inward to activate. Reducing low frequencies also helps by removing excess mud, making it easier for the instrument to sit in the mix.Using the 180* polarity reverseAnother similar source of feedback is resonance caused by the room acoustics and the PA system interaction. What happens is that certain bass frequencies can align with the echo causing what is known as a room mode. Modes can either amplify each other or cancel each other depending on the phase. By reversing the polarity, you can often eliminate resonant feedback. Simply depress to check for the best results in a given room.Reducing ground noiseSome artists like to have a stage amp in addition to the PA and monitors. The StageBug SB-4 Piezo is equipped with a thru output that can be used for a stage amp or a tuner. When it is used with a stage amp, you can sometimes encounter hum and buzz caused by a ground loop. Ground loops occur when the audio ground and the electrical ground conflict. A side access ground lift switch will help eliminate the noise. Simply depress when needed.


- Active DI optimized for piezo transducers
- Smoothes out peaks, eliminates squawk
- High pass filter eliminates resonance
- Ultra compact to fit in your guitar case
Show More
Show Less
- Audio circuit type: Piezo optimized active buffer
- Frequency response: 20Hz to 20kHz
- Total harmonic distortion: <0.006%
- Dynamic range: 100dB
- Input impedance: 5Meg Ohms
- Maximum input: +4dBu
- Gain: +2dB
- Output impedance: 330R Ohms
- Equivalent input noise: -101dBu
- Noise floor: -97dBu
- Intermodulation distortion: <0.01%
- Phase deviation: 10* @ 50Hz
- Switches: High Pass Filter, Phase, Ground Lift
- Low-cut filter: 50 Hz
- Filter slope: 6dB/octave
- Instrument input: 1/4" buffered with piezo optimized load
- Auxilary output: 1/4" buffered to drive guitar effects, amplifier or tuner
- Balanced output: Pin-1 ground, pin-2 (+), pin-3 (-)
- Polarity reverse: 180*
- Ground lift: Soft lift with 100 Ohms to ground
- Construction: 16 gauge steel chassis & outer shell
- Finish: Baked enamel
- Size: (L x W x D) 4.5" x 1,85" x 1.35" (114mm x 47mm x 34mm)
- Weight: 0.55 lbs (250 grams)
- Shipping size: (L x W x D) 8.25" x 5" x 1.75" (210mm x 127mm x 44mm)
- Shipping weight: 0.8 lbs (365 grams)
- Power: 48V phantom power
- Conditions: For use in dry locations only between 5*C and 40*C
- Warranty: Radial 3-year, transferable

When will I receive my shipment?

We ship on business days (Saturday, Sunday, and holidays are not business days). Packages ship from Mississippi, Nevada, New Jersey, or Ohio -- we cannot guarantee that any product will ship from a specific warehouse. Expedited Shipping (1-Day Air and 2-Day Air) is the only way to guarantee that you will receive an item within a certain time frame. Delivery estimates for expedited shipping options are listed on the product page for the item in question. All expedited shipments are delivered Monday-Friday.

Ground Shipping typically takes 1-4 business days from the date of shipment (for orders within the 48 contiguous United States). Residential ground and Free 2-Day shipments are delivered Tuesday-Saturday. Commercial ground and Free 2-Day shipments are delivered Monday-Friday. Make sure to select the proper address type for your address in checkout, as delays may occur if your selection is incorrect.

For APO/FPO customers, all orders ship via USPS. Expedited shipping is not available. Tracking for these orders is not available.

For customers shipping to a PO Box, the order may need to be shipped via USPS. For this reason, expected delivery dates cannot be guaranteed.

Do you ship to my location?

For most products shipping to the continental United States, customers may choose Ground, 2-Day Air, or 1-Day Air delivery. We also ship to Alaska and Hawaii; however, due to carrier restrictions, we cannot ground-ship to those states.

In addition, we ships to the following destinations, though some restrictions apply:

  • Canada
  • Puerto Rico
  • U.S. Territories

See instructions below for how to search the site by our eligible shipping destinations.

Note: We cannot change a shipping address on an order after it has shipped. If an order is returned because it couldn't be received at the listed shipping address, we will accept the return but will not refund the shipping charges.


We ship a lot of our most popular gear to Canada! To determine if item(s) ship to Canada, add the item(s) to your cart and enter your shipping postal code. Items that ship to Canada are sent via International Air, and delivery is typically 2-5 business days from the date of shipment.

Canadian orders are charged in U.S. dollars. Actual charges are dependent on your bank's conversion rate. Your bank may assess additional fees for international orders.

Although items shipped to Canada receive their full factory warranty, they must be returned to a United States service center for repairs. We're not responsible for any shipping or customs fees incurred in such a case.

Puerto Rico

We ship many items to Puerto Rico. To determine if item(s) ship to Puerto Rico, add the item(s) to your cart and enter your shipping zip code. Eligible items ship via International Air, and typically arrive 2-5 business days from the date of shipment.


We ship to APO/FPO addresses for free, though over-sized items may be ineligible. To determine if item(s) ship to your APO/FPO address, add the item(s) to your cart and enter your shipping zip code.

U.S. Territories

We ship eligible products to American Samoa, the Federated States of Micronesia, Guam, the Marshall Islands, the Northern Mariana Islands, Palau, and the Virgin Islands. Eligible items typically arrive 2-7 business days from the date of shipment.

What about customs fees?

Please be aware of customs fees such as taxes and duties, which are not included in our shipping charges. Customs fees vary from location to location. Please check with your local customs office for more information on the fees in your area. If you refuse to pay these fees, your order will not be delivered. We cannot refund shipping charges if an item is returned due to refusal to pay fees, and a restocking fee may be applied to cover the cost of return shipping. Customs fees are non-refundable.

Which items ship immediately?

Most orders ship the same business day your order is placed when you place a valid order before the shipping deadline.

Immediate shipment is available Monday-Friday. A valid order placed before 5 p.m. EST will ship the same day when using Ground or Free 2-Day shipping. Ground and Free 2-Day shipping orders placed after 5 p.m. EST will ship the next business day. Many orders using an expedited shipping method (2 Day Air or Next Day Air), and placed before 10 p.m. EST, will ship the same day.

Shipment and availability information updates from our warehouse to our website almost in real time. We are highly confident of the status of each item when you view a page. However, we do not reserve inventory being viewed or even placed in shopping carts, so we cannot guarantee an item's availability until you have placed your order. In particular, if you have been in the checkout area for more than about 10 minutes, we do recommend that you refresh the page to get the most current inventory prior to checking out.

What is a valid order?

A valid order is for a valid item at a valid price, placed with a credit card with complete and verifiable address and other information. Details.

Does immediate shipment mean immediate delivery?

Once an order is shipped, our carriers (Federal Express and UPS) typically guarantee a service time for when the order will be delivered to you. Our carriers have a very good record of delivering at their promised service time. We will ship immediately, and on all items, we will refund expedited shipping charges if the carrier's service levels for your chosen shipping method are not met.

If a product is in stock, is there any reason it will not ship immediately?

Exceptions are very unusual, but here are some examples of reasons that might prevent us from shipping immediately:

  • Warehouse, call center, or web operations lose power or telecom connectivity.
  • Warehouse, call center, or web operations lose capability due to adverse weather (blizzard), safety threat, or other factors.

What can I do if I don't feel you've lived up to your guarantees?

If you ever feel we have not lived up to any of our guarantees, we want to know about it -- and we want a chance to do right if we agree. Contact Us.

Recently viewed