Phantom Power DIN 45596 standard states that Phantom Power is supplied to be 48V ±4V (44V to 52V) on both pin 2 and pin 3 – referenced to pin 1. We found that some mixing consoles and I/O boxes will provide a slightly lower voltage than 44V. While this is outwith the widely used standard, most microphones, DI boxes or any other audio devices that require Phantom Power will still power up and operate just fine.


The former design of the Sound Bullet’s Phantom Power detection was to read Phantom Power and check that its voltage sits within the DIN 45596 voltage standards. However we decided to implement the capability of detecting voltages between 24V and 44V. When Phantom Power is found to be within that lower voltage range the 48V LEDs on the Sound Bullet will flash slowly, indicating that Phantom is present, however under DIN standards.


Please also read What happens if Phantom Power is higher than 52V

When the Phantom Power detected is higher than 52V the 48V LEDs will flash in an alarming way, indicating there is clearly a problem with your Phantom Power supply. Has this ever happened to you? Please let us know on support@sonnectaudio.com


Please also read Why do the Phantom Powers LEDs flash?

Phantom Power is a voltage of 48V (±4V) which is supplied to both pin 2 and 3 with reference to pin 1 of a console input XLR. So to speak, imagine two 48V batteries with both negative poles connected to the XLR pin 1 and one battery’s positive connected to pin 2 and the other battery’s positive pole connected to pin 3.



*Phantom Power circuitry is more complex than this but the image should give a good understanding.


Most Phantom Power indicators, for example the LED on a BSS AR-133 DI box will only show you the presence of Phantom Power without indicating whether one of the two legs is broken – in fact, most condenser microphones and DI boxes will still operate even if, say pin 3 of the XLR line is broken.


Being able to individually detect the Phantom Power voltage on pin 2 and pin 3 of the XLR line is very powerful since it can give you an instant diagnosis on the correct functioning of the balanced XLR line which runs all the way from the source on stage to the mixing console.


So for example if the wire soldered to pin 2 of the XLR has come off due to mechanical distress or the wiring is broken somewhere along the cable, the LED relative to pin 2 won’t light up. In 99% of the cases there shouldn’t be any problem with the Phantom Power supply circuitry within the mixing console but the fault will be on the cabling which interconnects your audio device/microphone to the mixing console.*


This is thoroughly explained on the Examples of Use page of the Sound Bullet manual.


*Please read also Why do the Phantom Powers LEDs flash?

The Sound Bullet is not designed to test intercom systems. Do you like this functionality? We’d love to hear what you think, drop us an email at hello@sonnectaudio.com

We wanted to ensure the Sound Bullet is a very fast tool to use – without too many buttons to press in order to quickly tackle different testing scenarios.


The headphones output shares the same amplifier as the internal speaker, this allows you to plug your headphones in to listen to an incoming signal without having to press another button – simply plug the headphones in!


The headphones/speaker amplifier is always fed by the 1/4” Jack – this means that if you plug the output of a musical instrument (keyboard, violin, etc) into the Sound Bullet’s 1/4” Jack this will automatically be reproduced by the speaker to check for its presence. This also means that when you route the internal generator to the Jack/Speaker you can instantly monitor whether you are generating pink noise or the 1kHz tone – in case you couldn’t remember if you pressed the signal type button.


Here’s a conceptual diagram to better understand the signal flow:



Also read
Why does the LED in the middle change colour or pulse

The LED by the signal selection button (image) indicates what type of signal is being generated as well as where it is routed to. When pink noise is generated (default) the LED emits a fixed light. When a 1kHz tone is selected (press SEL button) the LED will pulse slowly … just like a sine wave, got it?? 🙂



  • When the signal is routed to the XLR (default) the LED will illuminate in yellow
    When it’s routed to the 1/4” Jack/Mini-Jack and speaker the LED will illuminate in blue.
  • When the Sound Bullet is in cable-test mode the LED will blink white every 4 seconds.
  • When the Sound Bullet has reached 20% of charge the LED will flash 3 times every 6 seconds – time to find your charger..
  • When the Sound Bullet is out of charge, the LED will flash white 6 times every 2 seconds. Charge it up!



We designed the Sound Bullet to be very practical, hands-on and foolproof. A very handy use of the Sound Bullet is to plug it into the input of a speaker amplifier or of a self-powered speaker to quickly check for its functionality (check this video).


We have done many tests generating pink noise at a variety of output levels. +4 dBu is commonly used to calibrate VU meters, this is very handy, however it is a very hot signal and you wouldn’t want to plug it by mistake into the back of a speaker, because… well you will hear it !! So we decided to go for a more moderate maximum output level … yeah “Sound Bullet” does sound like something that comes out of a gun but we never meant it to be a deafening weapon ;-).


If you were wondering about the other two output levels well, glad you asked! We wanted to make sure the lowest output signal would light up the very lowest LEDs of the input meter of a mixing console*. -40 dBu seemed to light up the lowest input meter LEDs of all major brands of mixing consoles.


-20 dBu just nicely fits in the middle and works as a very usable level when checking the cabling of a self-powered line-array sound system while setting rigging it up in a noisy arena.


*when mixing console is set to default and input gains are set to “minimum”.

The Sound Bullet’s 1/4” Jack simultaneously works as an input as well as an output. This is great but it implies an important compromise, read on…


The impedance of an input should always be higher than the impedance of the output – usually 10 times greater, or more. This is why DI boxes have an impedance of around 1M Ohm while an acoustic guitar has a typical output impedance of 5k to 20k Ohm. Since the 1/4” Jack simultaneously works as input and output, its input/output impedance can only be one and we had to decide which one to pick, that is which function to optimise and which one to compromise.


We thought the function to be performing the best would be when the Jack is used as an output. For example, when you plug the Sound Bullet into a DI box – you’d want to PFL the input channel and observe it’s presence as well as its sonic quality. Whereas when plugging the Sound Bullet into the output of an acoustic guitar or keyboard you’d only want to check its presence as opposed to its quality. Hence we picked a lower impedance of 600 Ohm which works perfect when the Sound Bullet is outputting an unbalanced signal.


When a high-Z instrument output is connected into the Sound Bullet’s 1/4” Jack the impedance system is unmatched meaning the signal you’d hear through the speaker would sound a little quiet and distorted, however you’d still be able to tell that, for example, the signal chain of the pedalboard you’re testing is functional.

If you find this off-putting though, we’ve thrown in a little hack: when you select cable- test mode (press and hold SEL for 2s) the output circuitry is disconnected from the 1/4” Jack, which means its impedance will go a lot higher (3.5K Ohm) this will allow you to get a much better impedance match allowing the signal reproduced by the speaker to be louder and of better quality.


You’d like to learn more about impedance match? This is a great article: Understanding Impedance

This version of the Sound Bullet doesn’t cable-test the 1/4” Jack. Keep tuned though, we are in plans to develop a version which will have this feature, amongst many others!

To access the XLR cable-tester press and hold the SEL button for 2 seconds. One of the side LEDs will illuminate and the function LED will blink a white light every 4 seconds. Press the TO button to go through each pin of the XLR*. Watch this video to see how you can test XLR cables with your Sound Bullet.


Also read
Why does the LED in the middle change colour or pulse

Sound Bullet doesn’t generate Phantom Power.


But hey! Do you think it would be useful? We’d love to hear what you think, drop us an email at hello@sonnectaudio.com

Yes indeed. Simply slide the belt in the gap between the carabiner and the back of the case – between the two loops which hold the carabiner.


Roughly 2 hours. Battery discharge times and lifespan are indications which are always to be estimated since they rely on several variables and factors, including operational temperature, quality of recharge, battery overall-life, etc.


During R&D we carried out several tests where we exposed the Sound Bullet to its maximum current requirements (all LEDs turned on and -10 dBu pink noise sent to the internal speaker at full volume) and in this scenario the battery repeatedly performed for 2 hours and 20 minutes – which is a considerably long time since the Sound Bullet wouldn’t be used for more than, say 20 minutes per test.

Roughly an hour. We have put a lot of thoughts in creating a product which is robust and will last for a very long time in your career. We wanted to make sure the battery lifespan will be as long as possible and one of the main factors that defeats battery-degradation is to allow the battery to not be charged too fast.


You can read this useful article on battery life: Maximise Battery Life

Did you know the Sound Bullet is manufactured and fulfilled in Italy? VAT is a tax we have here, consisting of 22% which we add to the value of the goods. This tax can be deduced from your purchase, but you need to be special :). VAT rules apply depending on where you are receiving the goods.


Below are the rules depending on where you are in the world. See which one applies to you:


  • European Union:

– If you are VAT registered you will be deducted the VAT amount. When you checkout, please enter your VAT registration number in relevant field.


– If you are not VAT registered then we cannot refund you the VAT amount. Sry..


  • Outside of the EU (ie. America, Australia, India):
    You are VAT exempt so VAT will be automatically deducted on your purchase.


  •  Italy: The Sound Bullet is manufactured and fulfilled in Italy, if you are a private entity or a company we cannot refund you the VAT amount. In the VAT notes field, please enter your IVA number if you are a business or codice fiscale if you are private entity.


If you are still confused please get in touch with taxes@sonnectaudio.com, we don’t bite.

The creator and developer of the Sound Bullet, David Scorteccia is based in the UK. The Sound Bullets are manufactured in Perugia – Italy.


Every main part, PCB and chassis is sourced by suppliers within a hundred mile radius from the manufacturing company in Perugia, Italy. The manufacturing company in Italy looks after the assembly, test procedures, fulfilment and invoicing.

We offer a discount on an order of 10 units or more. We love word of mouth and genuine marketing from the people, please get in touch with us to find out more: hello@sonnectaudio.com

When the Sound Bullet is showing “low charge” (LED flashing white 3 times every 6 seconds) you should consider looking for your micro-USB cable and find a spare power socket “..where did I put it??”.


Sound Bullet showing low charge.

When the Sound Bullet’s battery is completely out of charge (device’s functionalities turn off and LED flashes white 6 times every 2 seconds) then it’s time to recharge the Sound Bullet.


Sound Bullet is completely out of charge.

Simply plug the Micro-USB charger into the side port and the LED next to it will turn red. When the red LED turns off the battery is fully charged, unplug it and you’re good test some bad-ass lines!


  • When the Sound Bullet’s internal battery is at 20% of its capacity the function LED on the top face will flash 3 times every 6 seconds, it’s time to find your charger.


  • When the Sound Bullet is completely out of charge the core functions will be switched off and the function LED will flash 6 times every 2 seconds.

The Sound Bullet has an internal speaker which allows you to listen to balanced (XLR) or unbalanced (1/4″ Jack) outputs. The internal gain structure for balanced signals is designed to interact with line-level signals and won’t be sufficient to amplify microphones. Besides, due to the small internal battery, the Sound Bullet isn’t capable to generate 48V Phantom Power.

According to our engineer team (and Ohm’s law!) there is absolutly no problem charging the Sound Bullet with a 5V / 1 ampere or more charger.
Since you use constant voltage (5V) the only factor that determines current draw is the load the Sound Bullet places on the charger.
So the Sound Bullet only draws as much current as it needs and no more.