DIY DI and Ramp Boxes?

[carboncomp]

Hello, first I hope this is the right section to ask in as I know its not really about a stomp box and more about how to interface with them in a DAW.

I'm on a tight budget trying to set up a home recording set up mainly for guitar and am a total noob with recording/production.

Right now I just have a 2 input audio interface, but would really like to use my guitar pedals in my DAW, and reamp some of my amps.

Are there any good open source builds people would recommend, would rather etch my own PCBs and use my stash of components than grab some DIY kit.

Seen on the internet lots of arguing over if a passive DI box can be used to reamp by swapping the input/output?

Think I'm going to try and build a Bo Hansen 1975 DI box after some really helpful suggestions on the groupdiy forums. But would love input on other options and reamp circuits.

http://www.hansenaudio.se/techpage.htm

Any help, advice or criticism is welcome.

[FiveseveN]

I just have a 2 input audio interface

What model is it? Is at least one of the inputs is high-Z you don't need a DI box.

And if anyone can explain to me why they need a "reamp box" there will be cash prizes¹.


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1. Prizes will not contain actual cash.

[carboncomp]

What model is it? Is at least one of the inputs is high-Z you don't need a DI box.

Yes, its a Universal Audio Volt 2 Audio Interface it has 2 inputs that can be mic or instrument level, but a indervidual DI box would give me more options regards what I plug into and has pass through so I can capture a clean DI track from the guitar, and still hear what I'm playing through a real amp, that I can then emulate in my DAW or use the reamp box to send the DI track into my amp and play around with amps setting and mic positioning without having to re-record the track each time.

And if anyone can explain to me why they need a "reamp box" there will be cash prizes¹.


______________________________________
1. Prizes will not contain actual cash.

I want one mainly for adding pedals into my DAW, so I can take a DI track or a sample, and play it out of the audio interface at line level, into a reamp box that will change from a balance XLR low impedance signal to a high impedance unbalanced instrument level the pedals are expecting, then back into the audio interface.

Or same process back on an amp so I can remic or change amp setting.

[ElectricDruid]

The Inputs and Outputs on the Volt2 can accept either balanced or unbalanced signals, so there's no need for a balanced/unbalanced conversion (they've already included it!).

https://help.uaudio.com/hc/en-us/articles/4409183769620-Volt-2-Hardware-Manual

Honestly, I think with a little bit of care about setting levels correctly, that interface can already do everything you want it to.

[carboncomp]

The Inputs and Outputs on the Volt2 can accept either balanced or unbalanced signals, so there's no need for a balanced/unbalanced conversion (they've already included it!).

Not to argue and just for my own clarification, but regardless of the outputs being balanced/unbalanced, it is a low impedance signal, rather than the high impedance from a guitar signal, so the volume/gain setting on the pedals will be different with the low impedance output then with a high impedance guitar signal, correct?

[ElectricDruid]

The Inputs and Outputs on the Volt2 can accept either balanced or unbalanced signals, so there's no need for a balanced/unbalanced conversion (they've already included it!).

Not to argue and just for my own clarification, but regardless of the outputs being balanced/unbalanced, it is a low impedance signal, rather than the high impedance from a guitar signal, so the volume/gain setting on the pedals will be different with the low impedance output then with a high impedance guitar signal, correct?

Perhaps in a few specific cases. Any modern pedal won't care, and by modern I probably mean anything from the late-80s onwards. A few old-fashioned things like fuzzfaces might not work quite the same, but everything else will be fine.

Given that the level you'll get coming out of the computer via the interface won't be the same as you'd get direct out the guitar, adjusting the levels appropriately was always going to be necessary anyway.

[FiveseveN]

Yes, my point exactly. A Fuzz Face won't sound "correctly" after a reamp box anyway: its impedance is relatively flat as opposed to the peaky low-pass of a pickup (+ controls).
The only potentially useful thing a box with a transformer can offer is ground isolation.

[ashcat_lt]

Aside from just ground isolation, it is true that in some situations, we actually can get just a little better S/N by sending a hotter signal out from the interface and attenuating it in analog on the way to the amp.

A passive DI wired backwards can accomplish the ground isolation, but it will be an inherent step up.  Many have pad switches which actually can help (even though they'd be wired "backwards"), but it doesn't quite give you the control of a continuously variable volume pot. 

Honestly, the best advice I've heard for reamping is to literally just plug it in via straight cables until and unless you encounter a real problem.   

For the other side of things, the Instrument input on the interface will gladly take a pedal output (which is a low-Z source, and BTW nobody ever thinks they need a "reamp" box to match a pedal to an amp input), and again barring any ground loop issues, you can kind of just do a straight wire split after any buffered pedal and not need the DI there either.

[moid]

If you've got two inputs on the DI there may be another way of doing this (which is what I do when recording). I run my guitar into a splitter box (basically a buffer with two outputs) so that I get two outputs from the splitter - one goes into the DI box (my clean dry guitar sound) and the other output goes to my pedal chain and from there to the second DI input. In the DAW these end up as the left and right channels of a stereo track, and I just separate them in software from there and mix them together (or not) to get the sound I want. That way I don't have to re amp because I can hear the FX audio when I'm playing, but still have a clean guitar track as well if I need some of it to be blended back in later. Not sure if that helps or not.

[Processaurus]

Good advice in the posts above, home recordists want DI's and reamp boxes because they see them in studios, but the main function of the DI or Reamp is to passively generate a balanced signal from an unbalanced signal to send through a long snake, and not be prone to picking up noise on the way. Recording in one room where the cables can be kept relatively short negates the need for that noise rejection.

I built a set of 1:1 reamp boxes (schematic in my gallery here, if it's working?) and I've gotten little use out of it in the studio. Plenty of use though as an extra DI for live sound though... The attenuator has been occasionally useful on its own to pad down line signal or large signals down to pedal level. I put in a transformer bypass to just use the attenuator. A simple potentiometer volume control in a little Hammond box could have the same utility. Over short distances you can make an XLR or balanced signal into an unbalanced signal simply by not connecting the cold (XLR pin 3) to anything, and connecting the hot (XLR pin 2) to the 1/4" tip. That's how XLR to TS adapter cables are wired and it is fine for short runs.

Any buffered pedal (Boss, etc.) serves as a good driver for a regular low impedance input (like 10k ohms is common) on an audio interface. I use the boss tuner with two outs often as a splitter to record the dry version of the guitar, and split off the other side to effects and the amp, in case the guitar tone ends up not being right.

The other utility of the DI or reamp is transformer isolation of ground loops. A good problem solver for live sound and recording studios with multiple rooms, but again, seldom a show stopping problem with connecting gear in one room, because most likely everything is on one electrical circuit. Ground loops can often be solved in small spaces by running everything off one outlet. Even if the amp is in another room it's not that bad to run an extension cord to it from the control room for improvised recording setups.