Transformerless directbox

[jimilee]

 Been searching with some googlefoo, can anyone give me some advice or point me to a transformerless direct box?

[kothoma]

Curious as ever, what else will go into this multi pedal?

dude wants a tube screamer a chorus and a delay a headphone amp and a direct box. Not sure how much will actually fit though.

With all that active circuitry, what's the DI box for?

An active DI box (transformerless) to have XLR connectors and a balanced line to the mixing desk perhaps?

Transformerless D.I.? tell me more.

For example:
http://www.paul-gemine.co.uk/diboxes.html
http://sound.westhost.com/project35.htm
http://www.sonelec-musique.com/electronique_realisations_di_001.html
http://www.sonelec-musique.com/electronique_realisations_di_002.html
http://www.sonelec-musique.com/electronique_realisations_di_003.html

[jimilee]

Thanks, I knew that post was around here somewhere! 

[raulduke]

Another nice simple one for you here as well:

http://www.muzique.com/news/guitar-direct-box/

Also, Jack Orman (AMZ Muzique guy) sells PCB's for his DI box circuit.

He is a good guy, and somewhat of a DIY legend (creator of fabled Minibooster and Mosfetbooster circuits) so is worth supporting!

[kothoma]

http://www.muzique.com/news/guitar-direct-box/

Neat. Probably can't be simpler. Thanks for this link!

Edit: BTW it's based on this: http://www.sg-acoustics.ch/analogue_audio/miscellaneous/pdf/OPA2134_DI-Box_r1.pdf

[Ettore_M]

Hey, jimilee! I have done a single-sided layout for the H&K Red Box (Classic, I think). I don't remember well, but it's half SMD. I could easily make a thru-hole version of it, too. If you're interested, I could post it. But then again, it's not verified..

Hector

[jimilee]

Hey, jimilee! I have done a single-sided layout for the H&K Red Box (Classic, I think). I don't remember well, but it's half SMD. I could easily make a thru-hole version of it, too. If you're interested, I could post it. But then again, it's not verified..

Hector

That sounds great, for a solder by numbers bassist, what is an H&K Red Box?

[RobA]

... what is an H&K Red Box?

I'm guessing this guy http://www.hughes-and-kettner.com/products.php5?id=110

[kothoma]

... what is an H&K Red Box?

I'm guessing this guy http://www.hughes-and-kettner.com/products.php5?id=110

Yep, a speaker simulator and DI box. Tuned to 4x12" I think.

[Ettore_M]

... what is an H&K Red Box?

I'm guessing this guy http://www.hughes-and-kettner.com/products.php5?id=110

Yep, a speaker simulator and DI box. Tuned to 4x12" I think.

Yes, indeed! I'm gonna be building this thing. I want to use it to record guitars direct from my amp, without using an attenuator or a microphone. Both are a little expensive for me, and I heard that this thing sounds really good!

Hector

[raulduke]

The AMZ Op-Amp project PCB is also a nice option:

http://www.muzique.com/tech/opamp_multi.htm

I built a reamp and DI with these PCB's and they both work fine and sound great!

[kothoma]

... what is an H&K Red Box?

I'm guessing this guy http://www.hughes-and-kettner.com/products.php5?id=110

Yep, a speaker simulator and DI box. Tuned to 4x12" I think.

Yes, indeed! I'm gonna be building this thing. I want to use it to record guitars direct from my amp, without using an attenuator or a microphone. Both are a little expensive for me, and I heard that this thing sounds really good!

Yes, forgot, it also takes speaker level signals.

[Ettore_M]

Yes. It has Amp In, Line In, and balanced XLR output and Speaker Output. This way the signal is finally "attenuated" in the speaker itself, and you get your guitars recorded from the XLR without using a microphone.
When I'll build ths thing and verify it, I'll post a build report and a build document.

Hector

[kothoma]

I've seen schematics of several versions of the Red Box.
But the speaker simulation always looks quite simple, a ROG Condor should be vastly superior.
What's nice is the input section with line in and speaker in/through.

[RobA]

Personal preference here but if you are taking the signal into the digital world after the DI, then forget doing the speaker sim in analog and use a 5-band parametric EQ on the digital side. You can get much closer to actual speaker/cab frequency responses this way and it is far more flexible/easy to change between various different enclosure geometries, number of speakers, etc. Even if you are just going into a board with high and low shelf plus one or two parametric EQ's you can probably get a better cabinet sim than you'll get out of any of the analog versions of cabinet sims I've seen.