DI/Re-amp box needed to route interface audio through pedals and back?

TelePaul

J to the R O C
Hi guys,

Long time, no post. Seeing a bunch of videos online of folks using stomp boxes and Hi-Z gear in routing trails. Most seem to just whip a line out from an interface and away they go, back am experiencing significant gain when I do (even when putting a Buffered pedal like a Boss Compressor first in the chain). So I obviously have impedance issues. A couple of things:

- The main out to my monitors can be routed back in without issue (as can a headphone out, I guess). Are these Hi-Z outputs? Or otherwise special?
- Is the best way to do this a line out to a re-amp box to a pedal to the Hi-Z input on my interface?
- Does the Hi-Z input mitigate against the need for a DI?
- Is a DI the same thing as a re-amp box?
- Anyone got any recommendations for a solid re-amp box (seems like pretty basic components, right?)

Thanks for the help!

P
 

keith.rogers

Bobby'); DROP TABLE USER
A picture would help here...

A DI goes from your guitar (plus pedal board) to the mic input of your interface. You may need to engage a PAD to get the level where the interface is happy about what it's getting given, but the DI should be doing its best to get a mic level signal and impedance output. If you've got buffered pedals or some hi-gain stuff going in, you will need a pad.

Now, if you're trying to push a dry-recorded guitar signal out of one of the interface's line outputs, you will want a re-amp box, and no, it's not the same as a DI. Why they cost so much, I don't know because I don't use one, but it seems that folks do use them. Get one with a variable output, and you should be able to match it up, I'd think. Make sure to use a TRS (balanced) cable between the interface's line out and the re-amp box. (You should have an interface with additional line outs other than just the monitor output jacs.)
 

Toastedgoat

New member
you need something to go from line level to instrument level with proper impedance match . Plus the ground issue. This is what the reamp box is for. A good one should have a ground lift. . DIYRE has one you can build for around $50.00 USD. ART has one for around $85.00 The ART has dual input and outputs. You could take your Di signal and bus it to two outputs and use two amps at the same time for reamping .
 

ecc83

Well-known member
Hi Paul, no such thing as "High Z OUTput" not at least in audio work as a rule. Other than the need for a high input Z for passive guitar, "impedance" rarely matters a ***t in the connection of audio devices. LEVEL is the king.

As I understand you, you want to take a feed from a line out (that is driving a monitor?) and run that back to a line or high Z input and you are finding the level too hot? Not surprised, especially as many Instrument/H Z ins have way too much gain and too little headroom. All you basically need is a Pot in a Tin. This consists of a volume potentiometer, 10,000 Ohms (10k) log, an input jack, and output jack and a third jack that preserves the thru signal to the monitor. P of P to make if you can solder.

But, there is a complication. The line out is almost certainly balanced as is the input on the monitor. The simple PiaT I just described will unbalance the feed and that could cause problems. No smoke! But possibly noise. You could, as mentioned, use the headphone signal. Not balanced but be aware that it is a TRS jack and one signal is on the tip and the other on the ring. Sleeve common.

I can do you a very crude diagram if you wish.

Dave.
 

Robus

New member
Might be. The Radial EXTC is a solid piece of kit with two separate loops, which is quite useful to me. It also has separate volume pots for input and output, which is helpful when using guitar pedals in the loops.

I use it because I prefer to track guitar FX, but some of my amps don't have an FX loop and some sound better when I don't use the loop. So rather than stack up reverb and delay pedals in front of the amp, I take a feed off the microphone preamp and blend the FX in on the way to the audio interface.

I'm thinking about trying the OP's suggestion of using the headphone out to feed the Radial, though I'll need to check the compatibility of the 1/4 inch jacks.

I would like to see your diagram.
 

ecc83

Well-known member
Might be. The Radial EXTC is a solid piece of kit with two separate loops, which is quite useful to me. It also has separate volume pots for input and output, which is helpful when using guitar pedals in the loops.

I use it because I prefer to track guitar FX, but some of my amps don't have an FX loop and some sound better when I don't use the loop. So rather than stack up reverb and delay pedals in front of the amp, I take a feed off the microphone preamp and blend the FX in on the way to the audio interface.

I'm thinking about trying the OP's suggestion of using the headphone out to feed the Radial, though I'll need to check the compatibility of the 1/4 inch jacks.

I would like to see your diagram.

Ok, will try to get it up tonight. (Detention! That boy at the back!)

Dave.
 

ecc83

Well-known member
Ok, first off cock up! (did this FOR YOU at 5.30 am) It is J1 and J2 that are insulated from the case*.

If you ignore Rb for the moment you just have a pot and a loop thru to keep whatever signal line you are sniffing intact.
S1 is an optional earth/ground lift switch but I advise it. C1 keep the whole thing earthed at RF if the ground is lifted, anything handy, 1nF to 100nF, any voltage, ceramic,foil...

The possible problem is that the incoming balanced line "sees" unequal loads on tip and ring. Now, 99.9% of the time this would not matter diddly but for the sake of a $0.1 resistor, Rb the line is much better terminated and that might cure a ground loop or other problem.

Most 10k pots are rated at 0.5W and so the circuit could be used to pinch a line level from a power amp up to around 300W. NB! The amp will STILL need its rated load and the pot can only feed line inputs NOT a speaker!

The case could in many instances be plastic, at line levels and low impedance sources hum is unlikely. The main danger is RF pickup and metal is best if you can do it.

Dave.
 

Attachments

  • Document (27).pdf
    21.3 KB · Views: 6
Top