Double Bass

Skyinbow Duo-Power IIB
Balanced Active Transducer Systems For Double Bass

The Skyinbow Duo-Power IIB Balanced Active Transducer System For Double Bass is an easy-to-install, piezo-based, rechargeable pickup system that features an electronically-balanced signal path that runs from from the system's handcrafted Skyinbow piezo transducer to the balanced output of the system's Pure Acoustic Power Series Duo-Power IIB miniature preamplifier. This balanced signal path has been designed to actively reject noise caused by external electrical interference. The combination of this active noise rejection with our highly-effective "Direct To Ground” system shielding topology means that the Skyinbow Duo-Power IIB delivers a stronger, clearer, and more accurate sound quality than previous generations of Skyinbow Pure Acoustic Active Transducer Systems. This superior performance further enhances the microphone-like sonic accuracy and tonal fidelity that Skyinbow Pure Acoustic Active Transducer Systems are renowned for.

A Skyinbow Handcrafted Transducer Mounted In A Double Bass Bridge

The Skyinbow Duo-Power IIB Balanced Active Transducer System For Double Bass is available as a Split System in which the handbuilt Skyinbow transducer is supplied attached to an inline jack socket that can be mounted on the tailpiece of the instrument. The Pure Acoustic Power Series Duo-Power IIB miniature preamplifier is supplied built into a separate guitar pedal format enclosure. 

The Balanced Advantage

The advantage of the Duo-Power IIB Balanced Active Transducer System having a balanced transducer driving into a preamplifier in which both the input and output are balanced is that the system as a whole is inherently resistant to interference from outside electromagnetic and electrical sources. This resistance to interference is further enhanced by Skyinbow Pure Acoustic’s new “Direct to Ground” circuit topology which ensures that any interference that is induced in the copper screens that protect the transducer and its cable is routed directly to system ground, keeping it away from the preamplifier’s audio circuitry entirely.

Connecting a Skyinbow Duo-Power IIB directly to the balanced microphone inputs of a mixing console, audio interface, acoustic amplifier etc. extends the balanced signal path all the way from transducer to microphone preamplifier. This extension allows double bassists to take full advantage of the system’s enhanced sonic accuracy and tonal fidelity.

When connected via a standard guitar lead to the unbalanced input of an effects pedal, looper, wireless transmitter etc., the Skyinbow Duo-Power IIB's balanced internal signal path and its "Direct To Ground” system shielding continue to reject external electrical interference. As a result, the Duo-Power IIB is capable of delivering a significant increase in performance over competing unbalanced systems. 

When connected to a balanced input, the Skyinbow Duo-Power IIB can be powered either by its onboard rechargeable power source, or by 48V phantom power from the microphone input itself. The system will switch over automatically to using phantom power when available, otherwise it will take power from its onboard rechargeable power source.

When connected to an unbalanced input, the Duo-Power IIB is powered by its onboard rechargeable power source.

Skyinbow Handcrafted Transducers For Double Bass 
Skyinbow handcrafted transducers for double bass are available separately, and are wired for either balanced or unbalanced operation. This enables double bassists to use Skyinbow’s renowned handcrafted piezo transducers with their own choice of preamplifiers from other manufacturers.

Pure Acoustic Power Series Duo-Power IIB Active Balanced Preamplifiers 
Pure Acoustic Power Series Duo-Power IIB Preamplifiers are also available separately, and can be purchased in a guitar pedal format. All are equipped with 3-conductor 1/4” (6.35mm) jack sockets wired for both balanced and unbalanced operation. This gives double bassists the option to use Pure Acoustic Duo-Power IIB preamplifiers with existing piezo transducers from other manufacturers.

All Skyinbow and Pure Acoustic products come with a limited 2-year parts and labour warranty.

How To Purchase
Pure Acoustic Ltd accepts payments (and all major credit and debit cards) via PayPal or via Bank Transfer.
To purchase a Skyinbow 
Duo-Power IIB Balanced Split Active Transducer System for double bass, a handcrafted Skyinbow transducer or a Pure Acoustic Duo-Power IIB preamplifier, please use the relevant Paypal "Buy Now" button below. 
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If you would prefer to pay via bank transfer, please get in touch with us 
via the “Contact Us” page on this website and we will send you all the necessary information. 

If you have any questions, or would like to learn more about our products, we'd be delighted to hear from you via our ”Contact Us” page. 

Dealer and Luthier Enquiries Are Welcome.

Price List - UK Customers Only
Prices include UK VAT, Postage and Packing
Non-UK Customers can access VAT-free prices on our Worldwide Webshop

Skyinbow Pure Acoustic Duo-Power IIB Balanced Active Transducer Systems
A ¼” (6.35mm) TRS jack to XLR Male Cable is required for Balanced and 48V Phantom Power Operation.
A System Recharge Cable Is Included.
Duo-Power IIB Balanced Split System for Double Bass (Guitar Pedal Preamp) - £249.99 

Skyinbow Handcrafted Transducers For Double Bass
Handcrafted transducers are supplied wired for both balanced and unbalanced operation.
We recommend the use of either a Pure Acoustic or other high quality piezo preamplifier.

Handcrafted Transducer for Double Bass 
(With Tailpiece Mounted Inline Jack Socket)  - £ 99.99 
Handcrafted Balanced Transducer With Custom Cable Length (Unterminated) - £89.99

Pure Acoustic Power Series Duo-Power IIB Balanced Preamplifiers
The Duo-Power IIB guitar pedal format preamplifier is fitted with 3-conductor 1/4” (6.35mm) jack sockets wired for both balanced and unbalanced operation.
A ¼” (6.35mm) TRS jack to XLR Male Cable is required for Balanced and 48V Phantom Power Operation.
A System Recharge Cable Is Included.. 
Duo-Power IIB Piezo Preamplifier (Guitar Pedal Format) - £169.99 

Pure Acoustic Power Series Accessories
Duo-Power System Recharge Cable - £14.99 

Technical Notes

Skyinbow Handcrafted Balanced Piezo Transducer For Double Bass

A handcrafted, balanced piezo transducer is a pretty rare sight. The manufacturing process is labour intensive and time-consuming. However, when you connect that balanced transducer to a piezo preamplifier with a balanced input and output (such as the Pure Acoustic Power Series Duo-Power IIB), you are rewarded with a strong, clear and accurate sound quality and you’ll understand why we take that path.
Installation of the transducer on a double bass requires the drilling of a blind hole in the bass shoulder of the bridge that is 5mm in diameter and 8mm deep. We recommend that the transducer is installed by an experienced violin repairer or luthier.

Pure Acoustic Power Series Balanced Piezo Preamplifier

Building on the multi-year design and development collaboration between an international team of designers and engineers that produced its predecessor, this latest Power Series preamplifier not only delivers an improved audio performance compared to all our earlier preamplifiers, but also allows musicians to choose between powering the Duo-Power IIB Power Series Active Transducer Systems from its rechargeable power source or 48V phantom power.

When connected to the balanced microphone input of a mixing console, audio interface etc.via a balanced cable, the Power Series preamplifier can be powered by 48V phantom power and outputs a fully-balanced signal, ensuring maximum signal quality and integrity. 
When the on-board rechargeable power source is providing the power, the Power Series preamplifier also outputs a balanced signal when connected 
via a balanced cable to a balanced microphone input, and an unbalanced signal when connected via an unbalanced cable to an unbalanced input - for example an acoustic amplifier, wireless radio system, DI box, effects pedal etc.

Onboard Rechargeable Power Source
The Duo-Power IIB's proprietary rechargeable, on-board power source incorporates a unique application of the latest power sensing technology and power management techniques that were first developed within the computer industry.The use of a supercapacitor to store an electrical charge eliminates the need to use conventional (and weighty) alkaline or lithium-ion 9 volt batteries, which helps to reduce battery waste and environmental damage.

Charging the supercapacitor is simply a matter of connecting a 9V (PP3) battery to the supplied System Recharge cable and plugging that cable's output jackplug into the output socket of the Duo-Power IIB Active Transducer System for between one and two minutes for a full charge. A fully-charged capacitor stores enough power to run the System for approximately 8 hours of playing time.

48V Phantom Power
The balanced microphone inputs of the vast majority of mixing consoles, audio interfaces, acoustic instrument amplifiers etc which are available these days are capable of supplying 48V phantom power. Originally developed to power condenser microphones, 48V phantom power is now often used as a convenient way of powering preamplifiers.

Direct To Ground Shielding
Skyinbow Pure Acoustic’s Direct to Ground shielding topology helps prevent noise by ensuring that any externally-induced electrical charge or current in the shielding that encases all Power Series Active Transducer Systems has a direct path to ground that bypasses entirely the systems' audio circuitry. 

Balanced Cables
Balanced cables - such as microphone leads - are made up of two conductors both of which carry identical copies the audio signal, one of which has its polarity reversed with respect to the other. When these two signals reach the preamplifier, the reversed signal has its original polarity restored. 

Any electrical interference picked up in the cable will have the same polarity in both conductors, which means that, when the reversed signal has its original polarity restored, the polarity of the noise in that conductor is reversed in relation to the noise in the other conductor, which cancels out the noise and leaves the original signal intact.

A balanced 1/4 (6.35mm) “stereo" jackplug to male XLR (TRS* to XLR**) cable is required to make a balanced connection between the Duo-Power IIB and a balanced XLR microphone input. This type of cable is readily available from bricks and mortar and on-line music retailers.

Unbalanced Cables
Unbalanced cables - such as standard guitar leads - are made up of a single conductor which carries the audio signal, and a woven or helically-wound copper wire screen. The screen acts as the ground reference for the audio signal and also, as its name implies. “screens" the audio signal from unwanted noises caused by including, for example, electrical and radio interference. However, the screen can also act as an antenna and pick up electrical and radio interference. Mains power cables, for example, are a common source of electrical noise and hum in unbalanced cables. 

In the Duo-Power IIB, the Direct to Ground shielding and the balanced connection between its transducer and its preamplifier combine to reject external electrical interference and help to prevent noise from entering the system’s audio circuitry.

Connecting a the 1/4” (6.35mm) jackplug of a standard jackp;ug to jackplug (TS*** to TS) guitar lead to the Duo-Power IIB’s balanced output unbalances the output signal at the point at which it leaves the system, which allows direct connection to the unbalanced instrument input of a wireless transmitter, effects pedal, looper etc. Although an unbalanced connection is less resistant to external electrical interference than its balanced equivalent, the strength and clarity of the Duo-Power IIB’s ourput signal means that this is unlikely to create a problem when using a good-quality guitar lead.

* Three conductor stereo jackplugs are made up of three sections - Tip, Ring and Sleeve - hence TRS.
** A fun piece of audio trivia is that the initials XLR stand for eXternal Line Return - not many people know that!
*** Two conductor mono jackplugs are made up of two sections - Tip and Sleeve - hence TS.

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Errors and Omissions Excepted. Prices and Specifications May Change Without Notice.

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LINND, Skyinbow, Pure Acoustic and Skyinbow Pure Acoustic Are Registered Trademarks of Pure Acoustic Ltd