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 the system’s handcrafted Skyinbow piezo transducer to the balanced output of its Power Series 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 Active Transducer Systems. This superior performance further enhances the microphone-like sonic accuracy and tonal fidelity that Skyinbow 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 only as a Component System in which the handbuilt Skyinbow transducer is attached to an inline jack socket that can be mounted on the tailpiece of the instrument. The Power Series Duo-Power IIB miniature preamplifier is built into a separate guitar pedal format enclosure.
The Advantage Of A Balanced Signal Path
The advantage of the Duo-Power IIB’s fully-balanced signal path is that it ensures that the entire system is inherently more resistant to outside interference from electromagnetic and electrical sources than conventional, unbalanced, piezo transducers and preamplifiers.
In addition, Skyinbow’s new “Direct to Ground” circuit topology ensures that any interference that is induced in the copper screens that protect the transducer and its cable is sent directly to ground, keeping it entirely away from the audio circuitry in the preamplifier’s signal path.
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.
Onboard Rechargeable Power Source and 48V Phantom Power
When connected to an unbalanced input, the Duo-Power IIB is powered by its onboard rechargeable power source, which can be recharged using one of our system recharge cables - the BATTSRC (requires a 9V (PP3) battery, the USBSRC (requires a USB 5v/2A mobile phone/tablet charger) or our 9VPSRC 240V UK 9v power adapter.
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.
These alternatives are explained in detail in the Technical Notes below.
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.
Skyinbow 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.
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.
Credit & Debit Cards
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Bank Transfer
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.
UK Retail Pricing
Prices include UK VAT, Postage and Packing
All Skyinbow products come with a limited 2-year parts and labour warranty.
Non-UK Customers can access VAT-free prices in our Export Webshop
Skyinbow 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.
Duo-Power IIB Balanced Component System for Double Bass
Transducer with Inline Jack socket and Tailpiece Mount / Guitar Pedal Format Preamplifier
With BATTSRC 9V Battery System Recharge Cable - £ 249.99 
(Requires 9v PP3 Battery)
With USBSRC USB System Recharge Cable - £ 259.99
(Requires 5V/2A Mobile Phone/Tablet Charger)
With 9VPSRC 240V UK 9V Power Adapter System Recharge Cable - £ 259.99
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 Inline Jack Socket and Tailpiece Mount) - £ 99.99
Handcrafted Transducer For Double Bass With Custom Cable Length (Unterminated) - £89.99
Skyinbow Power Series Piezo Preamplifiers
Guitar pedal format preamplifiers are fitted with 1/4” (6.35mm) input and output jacks wired for balanced or unbalanced operation.
Chinrest mounted preamplifiers are supplied with a length of unterminated cable.
We can also fit your own transducer into the chinrest provided that it has a minimum of 16cm of cable attached.
A ¼” (6.35mm) TRS jack to XLR Male Cable is required for Balanced and 48V Phantom Power Operation.
Duo-Power IIB Piezo Preamplifier (Guitar Pedal Format)
With BATTSRC 9V Battery System Recharge Cable - £ 169.99
(Requires 9v PP3 Battery)
With USBSRC USB System Recharge Cable - £ 179.99
(Requires 5V/2A Mobile Phone/Tablet Charger)
With 9VPSRC 240V UK 9V Power Adapter System Recharge Cable - £ 179.99
Skyinbow Power Series Accessories
BATTSRC - 9V Battery System Recharge Cable for Power Series Active Transducer Systems - £14.99 (Requires 9v PP3 Battery)
USBSRC - USB System Recharge Cable for Power Series Active Transducer Systems - £24.99 
(Requires a USB 5V/2A mobile phone charger)
9VPSRC - 240V UK 9V Power Adapter System Recharge Cable - £24.99
The USBSRC and 9VPSRC charging solutions are backwards compatible with all Skyinbow Power Series Active Transducer Systems. Existing owners of Skyinbow Duo-Power, Duo-Power II and Tri-Power Active Transducer pickup systems can purchase any (or all) of these charging solutions for use with their systems.
Modifications to the USBSRC and 9VPSRC charging solutions may be required for certain older (Non-Power Series) Skyinbow pickup systems. If you own an older Skyinbow system, please get in touch via our Contact page to check if this modification is necessary for your system.
Manuals
Duo-Power IIB Active Transducer System Owner’s Manual
Technical Notes
Skyinbow Handcrafted Balanced Piezo Transducer For Double Bass
A handcrafted, balanced piezo transducer is a 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 Power Series Duo-Power IIB), you will be rewarded with a strong, clear and accurate sound quality and you’ll understand why we go this extra mile.
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 Skyinbow 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 onboard batteries, which helps to reduce battery waste and environmental damage. This design allows Skyinbow to offer three methods of recharging the System Power Source:
The optional USB System Recharge Cable (USBSRC) enables any Skyinbow Power Series Active Transducer System or Power Series preamplifier to be charged from a 5V mobile or tablet USB charger or power bank rated at 2A or above. If you have a relatively recent mobile device, you probably already own a compatible charger. If you don’t, 5V/2A USB chargers are are easily available online or from your local mobile phone shop.
The optional 9VPSRC System Recharge Cable is based on a 240V UK 9V power adapter and can be used to charge any Skyinbow Power Series Active Transducer System or Power Series preamplifier.
We have also taken the opportunity to update our 9V battery-based System Recharge Cable (BATTSRC) by changing over to a fully moulded 9V battery connector and cable. This revised SRC is compatible with all Skyinbow Power Series Active Transducer pickup systems.
Charging the Onboard Rechargeable Power Source is simply a matter of plugging one of the above charging solutions into the output socket of the Duo-Power IIB Active Transducer System. One to two minutes is normally enough to fully charge the Power Source, unless it is completely flat when two to three minutes will ensure a full charge. A fully-charged Power Source stores enough power to run an integrated Power Series system or preamplifier for approximately 8 hours of playing time. However, we recommend that users always recharge their Power Series system or preamplifier before every performance to be sure, especially if using a BATTSRC where a run-down battery may increase charge times.
Active Transducer System Compatibility
All these charging solutions are backwards compatible with genuine Skyinbow Power Series Active Transducer Systems.
Owners of Skyinbow Duo-Power, Duo-Power II, Duo-Power IIB and Tri-Power Active Transducer pickup systems can purchase any the above charging solutions for use with their systems.
Owners of earlier (non-Power Series) Skyinbow pickup systems should note that modifications to these charging solutions may be required for your system. If you own an older Skyinbow system, before placing your order please get in touch via our Contact page to check if any modifications are required.
In Case Of Emergency
If a system recharge cable is not available for any reason, all Duo-Power, Duo-Power II and Duo-Power IIB pickup systems and preamplifiers can be recharged by plugging a standard guitar jack-to-jack cable into the system and holding the positive (small) terminal of a 9V PP3 battery against the tip of the free jackplug and the negative (large) terminal against its sleeve for one to two minutes.
Please note that this technique does not work on either Tri-Power systems or earlier, non-Power Series Skyinbow systems and may cause damage to those systems.
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’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 entirely bypasses 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.
Footnotes
* 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.
