Will a DI box do this?

[solo4652]

The band I've just joined is tooling up with a sw***y PA system. It has been suggested that we could place a mic in front of the bass and guitar amps and than feed the signal into the desk.

Now, I know nothing about PA systems, mics, signal processing etc, but it occured to me that a DI box might be a neater solution. But I don't know what I'm talking about.

So, instead of micing the guitar amps with free-standing mics, could a bass or a guitar be fed into a DI box which then splits the signal into amp-feed and also desk-feed?

Don't laugh, I'm learning....

Steve

[Noisyjon]

Bass will be great through a DI and a guitar will not.
A guitar needs the amp to supply the final part of it's sound, i.e. distortion, effects, etc, so a mic in front of the guitar amp is the way to do it.

Does that help?

Cheers,
JTB

[derrenleepoole]

If you amp has a DI out already, then I'd simply use that. The bass amp could then be run at lower level for backline monitoring for yourself and the drummer, letting the PA do all the volume work.

[Doddy]

Yeah you could use a DI box,or your amps DI out.
I'd rather mic up my rig,but have no problem with using a
DI box. Ideally though,I like to use both.

[lemmywinks]

I use a DI box over my amp's DI purely because if my amp were to cut out there'd still be bass FOH

I use an MXR M80 for DI. Never saw the point of getting a standalone DI box when i could have one that has distortion too!

[solo4652]

[quote name='derrenleepoole' post='661233' date='Nov 21 2009, 06:37 PM']If you amp has a DI out already, then I'd simply use that. The bass amp could then be run at lower level for backline monitoring for yourself and the drummer, letting the PA do all the volume work.[/quote]


Does my combo have a DI out? Here's a picture of the back of the combo:

[attachment=36785:002.JPG]

Reading the combo's manual suggests that I could use the Line Out socket to connect to a mixer. It also seems that I could use the Balanced Out jack to connect to an external PA, using the Select Switch to dictate whether the output from the combo is changed by the combo's switches/knobs ("Line out") or not ("DI out"). Apparently.

So, please correct me if I'm wrong, but it seems that I could take a lead from the Balanced Out jack, with the Select Switch set at "Line out" and that will enable me to put a signal into the mixer that I can control in the usual way with the combo's switches and knobs. Does that sound right, please?

Don't laugh - I'm learning.

Steve

Edited November 21, 2009 by solo4652

[lemmywinks]

Balanced out, the XLR one

[BOD2]

Yes, both of these outputs would do the job.

Use "Balanced Out" for longer cable runs as balanced signals are less susceptible to noise. But for a shortish cable run the "Line Out" would do the job just as well.

One thing to watch out for when using the "Balanced Out" (or any output on an XLR connector rather than a jack plug) is that if "Phantom power" is used on the mixing desk and applied to the channel to which the bass amp is connected then there may be risk of damage to the amp - you'd have to confirm that this would be ok with Roland. A well designed DI-out will be able to cope with Phantom power without any problems.

(Phantom power is used to send power to some types of mics - if none of your mics need phantom power then you can switch this off at the desk and there are no problems whatsoever).

[solo4652]

Thanks to everybody for their advice. I'll buy a 10m XLR - XLR cable and that should do the trick.

Steve

[Silent Fly]

Sometimes the DI/XLR outputs of the amps are not at the same quality level of dedicated DIs but in a band environment it’s probably difficult hear the difference anyway.

I would recommend you set "GND LIFT" to off.

Edited November 22, 2009 by Silent Fly

[thinman]

[quote name='BOD2' post='661364' date='Nov 21 2009, 10:03 PM']Yes, both of these outputs would do the job.

Use "Balanced Out" for longer cable runs as balanced signals are less susceptible to noise. But for a shortish cable run the "Line Out" would do the job just as well.

One thing to watch out for when using the "Balanced Out" (or any output on an XLR connector rather than a jack plug) is that if "Phantom power" is used on the mixing desk and applied to the channel to which the bass amp is connected then there may be risk of damage to the amp - you'd have to confirm that this would be ok with Roland. A well designed DI-out will be able to cope with Phantom power without any problems.

(Phantom power is used to send power to some types of mics - if none of your mics need phantom power then you can switch this off at the desk and there are no problems whatsoever).[/quote]

I did what obbm of this very forum suggested and got a short XLR lead and disconnected pin 1 for use with desks where there may be phantom power. That means there's no circuit for the 48v phantom supply but the signal's OK as it's carried on pins 2 and 3. Saves the worry of damage without the cost of an isolating transformer.

[Silent Fly]

[quote name='thinman' post='661939' date='Nov 22 2009, 05:17 PM']I did what obbm of this very forum suggested and got a short XLR lead and disconnected pin 1 for use with desks where there may be phantom power. That means there's no circuit for the 48v phantom supply but the signal's OK as it's carried on pins 2 and 3. Saves the worry of damage without the cost of an isolating transformer.[/quote]

You can achieve the same think using the "ground lift" switch.

In theory it [i]shouldn't[/i] be necessary though. Good DIs are designed to work without problems when connected to phantom power.

Edited November 22, 2009 by Silent Fly

[howieee]

i use the di on the back of my amp. it will suply the sound that is beeing sent to my speakers to the pa system so "my sound" is coming out the pa speakers. i cant see anythign going wrong with my amp as its extreemly reliable so dont see the point in a seperate di. if you dont have a di out then get yourself a di box. it should have 2 outputs. 1 for the pa in the form of an xlr and one in the form of a standard jack (same type that goes into your bass) that can go straight to your amp. i hope this helps!