The difference between a DI box and the amp DI output?

[ossyrocks]

I have a gig tomorrow evening where everything is being mic'ed or DI'd. FOH engineer, monitors, and full camera setup with sound fed from the desk mix.

 

I really want to use my vintage GK 400RB MKI on this gig, but the amp DI is untested and it's also on a 1/4" jack, and I'm not sure it's going to be ideal. I think 1988 was a little before amps really started to take DI Outs seriously.

 

My options are:

 

1. Use the 400RB, but use my Orchid DI Box in front of it and run a signal to FOH from that and to my amp for onstage monitoring.

2. Run my Ashdown RM800 and send a DI to FOH from that.

 

FOH, won't be the main reinforcement I don't think, the venue is not huge, so backline is mainly what the audience are going to get. The mics and DI's will be used for some reinforcement, but apart from vocals, are mainly for the cameras, filming and live stream which will be going out on the internet as we play.

 

What difference will FOH see in each of the two scenarios above?

 

Apologies for what may seem to be a basic question here, but it's something I'm really not familiar with.

 

Thanks,

Rob

[PaulThePlug]

Can we have some details so as we can watch?

[Lozz196]

Given that from the description the audience will be mostly getting their sound from whatever amp you’re using, and FOH just an added presence I’d go with the GK & Orchid DI option as the GK is your favoured amp.
 

But I’d take along the RM just in case the sound engineer wants a quiet stage with FOH handling the audience sound & volume, that way you’ll get your sound to FOH (as the RM only does post-eq).

[agedhorse]

Is this a multi-track recording with processing or post-production opportunities. If so, a pre eq DI would offer the most options "after the fact", in post.

[ossyrocks]

6 hours ago, agedhorse said:

Is this a multi-track recording with processing or post-production opportunities. If so, a pre eq DI would offer the most options "after the fact", in post.

The opportunity is there the take the stems from the recording yes. We may or may not do that. We've been in the studio twice recently recording tracks properly, and they are forming the basis of our recorded output. Any video we get out of this will just serve as "live video" for promo purposes. We're taking away whatever video/mix they put out on the internet though

 

10 hours ago, PaulThePlug said:

Can we have some details so as we can watch?

 

I wish I could tell you more, but I don't have specific links. The best I can do is point you here: https://www.facebook.com/MattAndPhreds

 

I believe the first set will be livestreamed from 8pm, after that I think it's just being recorded..

[ossyrocks]

9 hours ago, Lozz196 said:

Given that from the description the audience will be mostly getting their sound from whatever amp you’re using, and FOH just an added presence I’d go with the GK & Orchid DI option as the GK is your favoured amp.
 

But I’d take along the RM just in case the sound engineer wants a quiet stage with FOH handling the audience sound & volume, that way you’ll get your sound to FOH (as the RM only does post-eq).

 

I usually carry an Elf in the gig bag as backup. In case of the second scenario I could use that, it does actually sound great.

[BigRedX]

If the sound the audience get is from your rig then they should be mic'ing it up and not bother with DI.

[Phil Starr]

I'd imagine that any decent sound engineer who is going to be sniffy about feeds will have a box full of their favourite DI's and will split the signal for you.

 

If the Di on your GK is a jack then you need to know if it is a balanced output TRS or an unbalanced TS connection which will probably be too noisy to be ideal

[ossyrocks]

4 minutes ago, Phil Starr said:

I'd imagine that any decent sound engineer who is going to be sniffy about feeds will have a box full of their favourite DI's and will split the signal for you.

 

If the Di on your GK is a jack then you need to know if it is a balanced output TRS or an unbalanced TS connection which will probably be too noisy to be ideal

 

Ok, this is from the service manual. Not sure what this means.

[Phil Starr]

OK balanced is usually connected by a mic cable with three connections, it's noise cancelling so you can run long cables without picking up any electrical noise in the room. It feeds into a mic input on the mixing desk.

 

unbalanced has only two connections and is usually connected by a jack to jack instrument lead, if you run long cables then it will pick up electrical noises and generally you'd expect lower quality sound.

 

 

Your DI in the amp is effectively just another Aux out or FX out and probably the sound engineer would take this output and use a DI box to convert it to a balanced mic level signal. Depending upon their skill set and how long they have for a set up that is. It's probably important to know whether this DI is a pre or post signal. The pre signal is straight out of your bass with no processing by the amp. A post signal will have the tone you set up but crucially means any change in volume you make will also change the volume in the PA and mess up the FOH mix. There may also be a switch so you can change between a pre and post output.

 

I think you probably are going to have to trust your sound engineer to get on with things. You can't really have one band member being able to change the front of house sound even if it is the bassist Just show them your DI and let them choose whether to use it or their own gear.

Edited Thursday at 11:20 by Phil Starr

[agedhorse]

17 hours ago, ossyrocks said:

 

Ok, this is from the service manual. Not sure what this means.

That's an early 400RB for sure. 

[three]

Edit - oops, I realise this has gone - I hope it worked out well - please let us know
 

I’m afraid I can’t really comment on tech issues, though a nice, medium-sized (longish), mainly jazz-oriented venue. Decent PA and engineers in my experience. There may be more from the PA than you’d imagine and quite probably a fairly quiet stage - it’s a smallish space. Enjoy it!

Edited Friday at 09:50 by three

[ossyrocks]

6 hours ago, agedhorse said:

That's an early 400RB for sure. 

1st version, still going strong! I think it's late 80's.

[ossyrocks]

50 minutes ago, three said:

Edit - oops, I realise this has gone - I hope it worked out well - please let us know
 

I’m afraid I can’t really comment on tech issues, though a nice, medium-sized (longish), mainly jazz-oriented venue. Decent PA and engineers in my experience. There may be more from the PA than you’d imagine and quite probably a fairly quiet stage - it’s a smallish space. Enjoy it!

 

Ok, thanks for all the input chaps. Post match analysis 🤣

 

Lovely venue. I've been before before, but it must be at least 20 years ago, and it's the first time I've actually played it. Showtime is 8pm, but the engineer only gets started at 7pm, so it seemed very last minute, and sound/line check was completed 5 minutes before showtime. The engineer opted for my Orchid Classic DI which he phantom powered from the desk, he said it was better than theirs, so I got to use my old trusty GK 400RB. Everything was mic'ed or DI'd and stage was indeed was a comfortable but enjoyable level onstage. We're all gentlemen of a certain age (60's) and we're just not down with the IEMs I'm afraid, give me an amp and an old school wedge monitor  anytime. FOH did do quite a bit of the lifting I think, the room is much longer than I remember.

Surprisingly for a Thursday night in January every table except 5 at the back were reserved, so we had a really healthy crowd who were very generous in their appreciation.

This is quite a new band (less than a year since we started) and we made countless mistakes and cock-ups, but it's experience and we'll fix them as we go on.

 

Thanks chaps.

 

Rob

[three]

Thanks Rob - excellent - it sounds like all went well and a great experience.  A good audience too.  I'm with you on wedges or sidefills, I really haven't adapted well to IEMs.  I thought that FoH would be involved - it really is quite a long room.  Great staff and a friendly vibe too.  Sorry I missed it!

[ossyrocks]

7 minutes ago, three said:

Thanks Rob - excellent - it sounds like all went well and a great experience.  A good audience too.  I'm with you on wedges or sidefills, I really haven't adapted well to IEMs.  I thought that FoH would be involved - it really is quite a long room.  Great staff and a friendly vibe too.  Sorry I missed it!

The venue manager loved it, and has promised us some more dates, so we will be back. I think we'll be doing a Friday or Saturday next time though, so there will be a cover charge I think.

 

Rob

[three]

1 hour ago, ossyrocks said:

The venue manager loved it, and has promised us some more dates, so we will be back. I think we'll be doing a Friday or Saturday next time though, so there will be a cover charge I think.

 

Rob

Lovely! Please let us know of further dates - a really good venue and night out!

[Ramirez]

On 16/01/2025 at 11:18, Phil Starr said:

OK balanced is usually connected by a mic cable with three connections, it's noise cancelling so you can run long cables without picking up any electrical noise in the room. It feeds into a mic input on the mixing desk.

 

unbalanced has only two connections and is usually connected by a jack to jack instrument lead, if you run long cables then it will pick up electrical noises and generally you'd expect lower quality sound.

Balanced connections are very often carried on TRS jacks too, not just XLRs.  They’re not “noise cancelling”, just more immune to interference etc, which is useful in some scenarios. They’re usually line-level signals, apart from DI boxes and microphones.

 

Also, unbalanced does not mean “lower quality sound”. it’s just a different electrical system. Many extremely high-end audio equipment of all descriptions use unbalanced connections - it doesn’t sacrifice any ‘quality’ as long as everything works as intended.

Edited Saturday at 13:04 by Ramirez

[agedhorse]

Actually, balanced inputs do cancel noise that is common to both the + and - conductors, either through an input transformer or differential amp at the input stage. They amplify signal and noise that is not common to both conductors. 
 

Balanced is independent of level or connector type (provided it has 2 terminals plus ground… and ground may not be connected at both ends either because it is purely for shielding and not necessary for a balanced system to work. 

[Phil Starr]

6 hours ago, Ramirez said:

Balanced connections are very often carried on TRS jacks too, not just XLRs.  They’re not “noise cancelling”, just more immune to interference etc, which is useful in some scenarios. They’re usually line-level signals, apart from DI boxes and microphones.

 

Also, unbalanced does not mean “lower quality sound”. it’s just a different electrical system. Many extremely high-end audio equipment of all descriptions use unbalanced connections - it doesn’t sacrifice any ‘quality’ as long as everything works as intended.

the idea is to help people by meeting them where they are. Mic cable doesn't mean mic level. I didn't say always lower quality sound, I used the word generally, it's practial advice aimed to helpsomeone struggling to maem head or tail of setting up a PA system for live music who will wonder why the sound engineer would prefer a balanced line. I'm not disagreeing with your comments but sometimes it's good to keep things simple if you want to be helpful. If maybe you read the words you'd have realised I'd allowed for exceptions but decidednot to make it more complex than it need be.

[Ramirez]

3 hours ago, Phil Starr said:

the idea is to help people by meeting them where they are. Mic cable doesn't mean mic level. I didn't say always lower quality sound, I used the word generally, it's practial advice aimed to helpsomeone struggling to maem head or tail of setting up a PA system for live music who will wonder why the sound engineer would prefer a balanced line. I'm not disagreeing with your comments but sometimes it's good to keep things simple if you want to be helpful. If maybe you read the words you'd have realised I'd allowed for exceptions but decidednot to make it more complex than it need be.

Fair enough, but I still think accuracy is important even when simplifying things - an XLR cable is not just a ‘mic cable’, and stating so could cause confusion in other situations. And unbalanced connections really don’t mean a lower quality sound, generally or otherwise.

[Downunderwonder]

1 hour ago, Ramirez said:

unbalanced connections really don’t mean a lower quality sound, generally or otherwise

It only takes one noisy light to make a hash of your pristine unbalanced signal.

[Ramirez]

6 hours ago, Downunderwonder said:

It only takes one noisy light to make a hash of your pristine unbalanced signal.

 

Certainly! It’s always a good idea to balance them as soon as possible with a DI box, whether that be a guitar signal or an unbalanced out from an amp.

 

Speaker and headphone feeds are usually unbalanced though, without problems. And there’s the added bonus that you send a stereo unbalanced signal down one XLR if you’re willing to take the risk with noise! I’ve done that a few with robust line-level signals from keyboards on occasion- worked fine and cut down on stage clutter.

[tauzero]

5 hours ago, Ramirez said:

 

Certainly! It’s always a good idea to balance them as soon as possible with a DI box, whether that be a guitar signal or an unbalanced out from an amp.

 

Speaker and headphone feeds are usually unbalanced though, without problems. And there’s the added bonus that you send a stereo unbalanced signal down one XLR if you’re willing to take the risk with noise! I’ve done that a few with robust line-level signals from keyboards on occasion- worked fine and cut down on stage clutter.

 

The difference with speaker and headphone feeds to line-level or mic-level feeds is that induced interference is relatively much, much smaller relative to the signal, and the input impedance to a speaker or headphones is considerably lower. Line level is around 2V p-p, mic level is 200-300mV p-p, while 5W being sent to an 8 ohm speaker is around 24V p-p.

[Ramirez]

4 hours ago, tauzero said:

 

The difference with speaker and headphone feeds to line-level or mic-level feeds is that induced interference is relatively much, much smaller relative to the signal, and the input impedance to a speaker or headphones is considerably lower. Line level is around 2V p-p, mic level is 200-300mV p-p, while 5W being sent to an 8 ohm speaker is around 24V p-p.

Quite- I was using them as examples that ‘unbalanced’ isn’t inherently ‘lower quality’ - it’s just a different system.

 

‘Line level’ and ‘headphone level’ can be quite close though. And they can all vary a lot!

 

 

Edited Sunday at 17:38 by Ramirez