DI Boxes

Lestratcaster

Who uses them live? Do I need to get one? I know it gives a purer signal into the desk as there's no mic bleed from say a loud drummer. But is it worth getting one for the hassle of extra stuff to set up? Earlier this month I played at a venue where the soundguy told me to plug 2 speaker cables in, one into the DI box and one from there into the speaker cab.

John_P

Unless you're using one with some kind of speaker simulator like the HK redbox then it will sound awful.      
I know a sound guy that prefers to do this instead using a mic but it's usually a lot easier to mic up an amp I find. 

It is handy to have a way of going direct to the desk in case of an amp failure - amp in a box pedal and di box or red box etc but if you are using a conventional amp and pedal setup then you don't need one. 

octatonic

For live- usually not for guitar.
Always for bass.

Since reaping has become a thing in the last 10 years one thing I do when recording is ALWAYS take a line out from the guitar and track the guitar completely dry (but muted) so I can reap later if need be.
It has saved many a production when a guitarist uses too much gain- this happens a lot.

ICBM

It should actually be slightly less hassle than mic'ing the speaker - you don't need to worry about placement, knocking it etc.

If you're using one with an amp (not a modeller/FX unit) you will usually need one with speaker emulation, or it will sound like crap. Some modern desks have speaker emulation on-board, but don't count on it. A common one with emulation is the H&K Red Box. I have one, it works well enough - it doesn't sound exactly like a mic'ed speaker, but I doubt it really makes much difference out front. There are others, including some basic passive ones like the Peavey EDI which surprisingly sound very good.

Also, if your amp has more than one speaker jack, don't connect the box between the amp and the speaker like the soundman did - simply connect any unused speaker jack to the box (you don't even need to use a speaker cable for this, if there's no speaker current going through it) and leave the speaker connected to the amp as normal… it's more reliable and hence safer for the amp than going through the two extra connectors.

(The only exception to this is an amp like the Peavey Classic 30 or Fender Hotrod, where the amp switches impedance automatically when you use the extension speaker jack - then you do need to go via the box.)

simonk

I've used a Palmer PDI09 and Radial JDX on a regular basis and had great results from both. Not having to worry about 57's, or any other mics for that matter, being knocked away from cabs on cramped stages is a good thing

timmysoft

I use the Palmer junction and it's excellent!

Beexter

ICBM said:

It should actually be slightly less hassle than mic'ing the speaker - you don't need to worry about placement, knocking it etc.

If you're using one with an amp (not a modeller/FX unit) you will usually need one with speaker emulation, or it will sound like crap. Some modern desks have speaker emulation on-board, but don't count on it. A common one with emulation is the H&K Red Box. I have one, it works well enough - it doesn't sound exactly like a mic'ed speaker, but I doubt it really makes much difference out front. There are others, including some basic passive ones like the Peavey EDI which surprisingly sound very good.

Also, if your amp has more than one speaker jack, don't connect the box between the amp and the speaker like the soundman did - simply connect any unused speaker jack to the box (you don't even need to use a speaker cable for this, if there's no speaker current going through it) and leave the speaker connected to the amp as normal… it's more reliable and hence safer for the amp than going through the two extra connectors.

(The only exception to this is an amp like the Peavey Classic 30 or Fender Hotrod, where the amp switches impedance automatically when you use the extension speaker jack - then you do need to go via the box.)

Another Palmer Junction user here, very happy with it but have only ever used it in between speaker out and cab input.
@ICBM I'm a bit confused by your suggestion  (easily achieved due to my lack of knowledge!) - my 2 amp heads (Orange Rocker 30 and Mess Express 5:25+) both have multiple speaker outs (4ohm and 8ohm) - would plugging the DI box in to a "spare" speaker out on the amp not affect the impedance going to the speaker? For example, the Rocker has 2x8ohm speaker outs and according to the manual, if you just use one, you should only plug in an 8ohm speaker but if you use both, you should plug a 16ohm speaker into each one.
Also, wouldn't the speaker outs always provide speaker current?

I'm not questioning your knowledge in the slightest, I'm just trying to improve my understanding. 

ICBM

Beexter said:

@ICBM I'm a bit confused by your suggestion  (easily achieved due to my lack of knowledge!) - my 2 amp heads (Orange Rocker 30 and Mess Express 5:25+) both have multiple speaker outs (4ohm and 8ohm) - would plugging the DI box in to a "spare" speaker out on the amp not affect the impedance going to the speaker?

No - the input impedance of the DI box will be at least 10Kohm or so (I don't know exactly what the Palmer's is, but it will certainly be about this high - that's what the Red Box is), so it won't change the impedance load on the amp significantly.

Beexter said:

Also, wouldn't the speaker outs always provide speaker current?

No, because the current will only be drawn if there is a low impedance like a speaker to do so - otherwise it's effectively just a signal voltage (albeit a large one).

Neither of those amps have impedance switching, so it's best to just connect any of the unused jacks to the DI box, a simple patch cable is fine.

There isn't a *huge* difference, but since a valve amp can be seriously damaged if the speaker circuit goes open, adding another cable, two extra plugs and sockets, and the solder connections on the inside of the DI box into the speaker path is just increasing the risk of something going wrong if you don't need to do that.

Beexter

Brilliant stuff @ICBM, thank you. Wiz awarded