DX168 – Need Direct Input Box?

[Bryce]

From what I’ve read, the DX168 accepts both Mic and Line level inputs. If all instruments are within 10-15ft of the box, is it really necessary to use a DI box between the instrument and the DX168?

My understanding is that a DI box (1) converts unbalanced signal to balanced, (2) converts high impedance to low impedance, and (3) some DI boxes offer a ground lift.
So, is there any additional benefit to converting signal to a balanced signal other than a long cable run? If I’m 10ft from the stage box does the DI box offer any benefit on this point?
If the stage box can accept Mic level inputs, do I need a DI box to convert high impedance signal to low impedance?
The ground lift is where I’m thinking there may still be a benefit. If I’m playing an electric guitar with a pedal board, could I possibly benefit from the ground lift feature of a DI box in some circumstances?

I’m not at all pretending to be an expert on DI boxes, so please correct me if any of my understanding is wrong, and let me know if you think there are cases where I would/wouldn’t need a DI box.

Thanks!!
Bryce

[Mike C]

The inputs on the DX168 are all balanced XLR, you would need properly wired balanced to unbalanced cables to connect to the stage box.

With a hardwired cable between the stage box and the instrument you could accidentally apply phantom power to an input on an instrument, a DI box would block that.

How many instruments are there?

[Bryce]

Thanks, Mike. Does a balanced signal have any other benefit than noise rejection? Once the signal reaches the DX, it’s converting it to digital and balanced/unbalanced is irrelevant. Or am I missing something?

You have a great point about accidental phantom power protection, though. And buying DI boxes might be worth it just for that “insurance.”

The setup is for our youth group. We typically have Bass, Drums, Keyboard Piano, Acoustic, Electric. I have a few more people interested in playing, and I’d like to possibly add click, synth/pads, Nashville acoustic, possibly SubSynth.

My thought has been, better to reduce the number of items in the signal chain (and equipment on stage), but I do think you have a very fair point about phantom power.

[Mfk0815]

The rule of thumb for me is to use a DI box on anything which is not a mic and do not provide a balanced XLR signal. the three mentioned benefits are quite enough to use them, but it helps also to keep your stuff in a structure. because you can place the DI box near the instrument, you only need a bunch of XLR cables to connect the signal sources to your stagebox.
So I have some passive DI boxes (Palmer PAN 01 and PAN 04) for all sources like keyboards and other line level sources. for passive or acoustic guitars I have some active DI boxes (Palmer PAN 02). And I am quite satisfied with them.

[Showtime]

It is not only the fantom power, it is also impediance.

There is a lot writen on the internet why to use a di box en witch di box for witch instrument.

Guitar is mostly high impediance and the dx168 is low impediance, without a di box there will be a loss of sound.

Richard

[Mike C]

The overall quick answer is anything that has a 1/4inch jack for an output use a DI box to interface it to the sound system.

Active devices like keyboards, bass guitars that have built in preamps, anything powered with a plug in power supply or batteries can generally use a passive DI box.
Instruments that are passive like acoustic guitars with out a built preamp generally are
better off using an active DI box that has a much higher input impedance.
There are also some vintage keyboards/pianos that are passive!

[Bryce]

Thank you all for the discussion.
Mfk, my original point was that 2 of the 3 benefits are already redundant by the DX being ~10ft away from the instruments and it’s acceptance of both line & mic levels. For the 3rd benefit, it’s also easy enough to listen to see if a ground lift is needed. Thank you for the DI recommendations. I’ll check them out.

Showtime, there definitely is a lot out there. I’ve spent a lot hours reading about DI Boxes and a fair bit of time today trying to better understand impedance. The DX168 does accept line level, high impedance signal. Maybe a DI box would do a better job converting the impedance?

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