SEE  |  HEAR  |  BELIEVE
Shopping Basket
Pay via WorldPay or PayPal
DM Plus Account Log In

Phantom Power and DI boxes

Q. What is Phantom Power and when do I need it?
A.
Most mixing desks these days will have a button labelled ‘Phantom Power’ or 48V. Condenser microphones need a polarising voltage and power for their built in amplifiers. Some condenser microphones can also be battery powered (eg ATM 33a, our most popular mic). Condenser mics are therefore generally more sensitive than dynamic mics and usually have a better frequency response particularly in the higher frequencies. If you need condenser microphones you need phantom power on the mixer.

Q. What do you call a long length of unbalanced cable typically over 10m of mono jack to jack?
A.
An aerial. If you want to avoid radio stations & taxi cabs use balanced lines. You will need a DI box when you are sending guitars or keyboards down a long mic cable or multicore. Further, a low impedance/balanced line maintains the integrity of the signal in strength and frequency response.

Why have a direct injection box?

Q. DI boxes seem to be an extra expense. Do I really need them and what benefits do they offer?
A.
Yes - if you want to do the job properly. DI’s (Direct Injection Boxes) are an essential. They benefit us in a number of ways, explained as follows:

1. Maintains the integrity of signal, even down long lengths of multicore, both in strength and frequency response

2. Interface an unbalanced output to a balanced input i.e. jack from guitar or keyboard to XLR on mixer

3. Pad attenuation tames high signal levels i.e. from a synthesiser.

4. A ground lift switch overcomes hum caused by ground loops between equipment.

5. Prevents phantom power from reaching unbalanced source - (preventing equipment damage)

Surely a small price to pay for quality sound - especially if you buy from us at DM Music!

When to use an active DI box?

An active Di box is recommended for use when an induction loop is also in operation. The active circuitry will not pick up the inducted signal in the way that the transformer in a passive DI box tends to.
Also, use an active DI box in applications where the box is situated very close to a powerful amplifier or unit containing a large transformer which could cause interference.
Electric or electro acoustic guitars tend to benefit from an active DI.


The DAC came today as expected and were very impressed indeed. They said they thought it was the best installation of a projector and screen that they had ever seen in a medieval church.
David Cutts
St Margaret’s, Ipswich
The Engineers have done a very neat job and it was a great pleasure to welcome them to All Saints Church.
Keith Thacker
All Saints, Burnham-on-Crouch, Essex
Please pass on my thanks to the team for the excellent job they did installing our new system. ...Very impressed with installation team and teaching session
Revd Karen Knight
Old Independent Church, Haverhill
Just to let you know that the gear DM installed is great and has made a big difference to our sound.
Adrian Rose
Linton Free Church, Cambridgshire
A fantastic 4 days of effort, hard work and advice. An outstanding installation which matched the high level of professional conduct by the 3 workers. Thank you for the fantastic service!
Steve Thompson
City Gates Christian Centre, Ilford
We were most impressed by the professionalism of your approach, from initial planning through to installation. We would certainly recommend DM to other churches.
John Alpass
Holy Trinity, Claygate, Surrey