Re-Amp with DI

L

LaceSensor

Member
Hello,

I was reading that re-amping using a standard DI box (in reverse) is not a good idea because the signal level coming from the audio interface output would be too hot (level too high) for the DI box.

I have a Warm Audio active DI which has a -30dB PAD. Would this device work for re-amping using gtr. effects stomp boxes?

I am not planning to use this to re-amp with an actual amp. I just want to process audio through gtr. stomp boxes.
 
From what I understand, a ReAMP circuit basically is just a DI circuit run backwards.

I can't picture it hurting anything, but you'll also have to do some wonky things with F to F XLRs to even connect it.

I suppose it wouldn't hurt to put a meter in there to see what the levels going to and from the DI would be
 
The idea that a re amp box is just a DI in reverse is a bit of a myth which probably started from the practice of running an amp in the studio fed from a guitar in an isolated control room using two back to back passive DI boxes over a mic tie line.

In principle you don't need anything to re amp except a guitar cable from an AI output to the guitar amp but in practice there are problems.

First off, level is likely to be way too hot giving excessive distortion and often high noise levels. The simplest 're amper' is therefore a pot in a tin to reduce the level, usually by 20dB (x10) or so. Next you are almost certain to create a hum loop and so a 1:1 ground isolating transformer is needed. Does not need to be a super expensive traff, only handling around neg 20 dBu or less.

Mssrs Orchid Electronics do a good one for a very fair price.

Dave.
 
ecc83 said:
The idea that a re amp box is just a DI in reverse is a bit of a myth which probably started from the practice of running an amp in the studio fed from a guitar in an isolated control room using two back to back passive DI boxes over a mic tie line.

In principle you don't need anything to re amp except a guitar cable from an AI output to the guitar amp but in practice there are problems.

First off, level is likely to be way too hot giving excessive distortion and often high noise levels. The simplest 're amper' is therefore a pot in a tin to reduce the level, usually by 20dB (x10) or so. Next you are almost certain to create a hum loop and so a 1:1 ground isolating transformer is needed. Does not need to be a super expensive traff, only handling around neg 20 dBu or less.

Mssrs Orchid Electronics do a good one for a very fair price.

Dave.
Click to expand...
Also need to include impedance matching, which is arguably the most critical signal parameter in this situation.

Also I do not intend to use an amp here. Just want to loop through some stomp boxes and back into DAW.
 
An active di box will not work backwards. A passive one will, but the gain staging will be way off.

The line out of the interface is already too hot for the Amp, running backwards through a di box would add level to the already too hot signal.

But again, you can't run signal backwards through an active di. Nothing will come out.
 
LaceSensor said:
Also need to include impedance matching, which is arguably the most critical signal parameter in this situation.

Also I do not intend to use an amp here. Just want to loop through some stomp boxes and back into DAW.
Click to expand...
We never "match" impedance for audio and in any case there is no impedance issue, you are going from quite low, a few K at most, to extremely high, most guitar amps are 1meg Ohm and so are pedals if they are any good.

Dave.
 
Farview said:
An active di box will not work backwards. A passive one will, but the gain staging will be way off.

The line out of the interface is already too hot for the Amp, running backwards through a di box would add level to the already too hot signal.

But again, you can't run signal backwards through an active di. Nothing will come out.
Click to expand...

Good to know, thanks!
 
Hello Lace,

Depending on what kind of re-amping you are going to try, follow those step :

- Select a dedicated output bus on your DAW and decrease the volume to -30 dB Vu at least.
- Plug the corresponding output to your DI (usually jack TRS M to XLR F)
- Use a pad if available on your DI
- Plug into the instrument input of your amplifier
- Slowly increase preamp volume gain up to the value you are seeking for
- If the resulting signal is really too low, disengage the pad on the DI (be careful, a -20 dB pad is a huge difference in signal level)
- If it is still to low, increase the level of the output bus progressively.

I use a Radial Pro DI (passive DI) into either a Sansamp or a SWR with great success.

I wish you the best record and tons of fun !

Cheers from Canada.
 
You must log in or register to reply here.
Back
Top