Wolfbox DI

Came across a couple more Triad A-11j transformers so I had to build another Wolfbox DI.  Once you play bass or guitar through one of these, you'll never want to plug in any other way.

Can you post the diagram ?

I made a couple for a producer recently. I prefer the ones we have at the studio using the utc a-11 vs the triad a-11. But that’s just me

Rob Flinn said:

Can you post the diagram ?

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Wolfbox
http://www.audiographicservices.com/wolfboxv4.pdf

pucho812 said:

Wolfbox
http://www.audiographicservices.com/wolfboxv4.pdf

Click to expand...

Thanks Pucho.

Try the Bo Hansen DI and see what you think.

I made one of these a few years ago, just with a different transformer with similar specs. It sounded really bad compared to my other DIs. Looking at the resistors, i/o impedances and instruments involved made me think that the wolfbox is a big misalignment box which *maybe*, in a few occasions might sound cool. Other than that it´s crap for my taste. Back to Bo Hansen DI and G9....

My buddy recently found one of these transformers laying around somewhere so naturally I had to make him this DI.

Here's the guts.

I've been thinking about building one of these, and wanted to thank you immensely for this post. The diagram and (especially) the photos help so much.

While looking at other builds of this DI online, I've tried to trace the schematic to exactly what they were doing in their builds and almost always became totally confused as to how they got to their final conclusion of wiring. Yours makes total sense to me, and I thank you!

Cheers!

PS -- curious as to what kind of input jacks you are using in this build? Also, the two resistors, are those 1k and 10k? (I've seen those two listed on the schematic)

jensenmann said:

I Looking at the resistors, i/o impedances and instruments involved made me think that the wolfbox is a big misalignment box which *maybe*, in a few occasions might sound cool. Other than that it´s crap for my taste.

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With such a low input impedance the high end roll off will be quite pronounced, the low end headroom is also limited

It will be more like a lo-fI DI box maybe it’s cool for certain types of sounds, like a more vintage tone, otherwise it will be a bit muddy for sure

Reviving an old thread here, if I may.
I’m repurposing an old Sescom DI, removing the questionable transformer and replacing it with an A-12J.
What type of pot is needed for the attenuator?
Linear? Log?

Thanks in advance for any info.

Anthony.

Log, but don't wire up the attenuator as per the original Ed Wolfrum schematic that was floating around on the internet. It has an error.

Wire it up using common sense, and it will work great! If you have any questions, ask and I can help.

What type of pot is needed for the attenuator?

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Try it with and without a pot and see what you think of the sound. With a passive pickup, all the components are very interactive and a pot (or any resistance) will affect the tone. I don't build passive DIs with a pot.

The magic is just in the Triad transformer. It sounds really great. And not a small difference from others.
I used a A-10J and compared it to my other transformer DIs (LS-10, JE-DB, WE 111c) and with a passive bass input (P-bass) and it was distinct and great. My impression is it sounds already compressed and glued into a mix. Not something I would always want to use - but great when you do.

Also compared to my two Bo-Hansen DIs (one OEP & one Haufe). The Bo Hansen is a great utilitarian DIY DI, but my opinion is it isn't in the same realm. I realized I was never using them with better options available. Others may disagree. My go-to DI for guitar however is a tube DI.

On the true Wolfbox, the pot/attenuator is switchable in/out of the circuit.

I recommend building it either this way, or ignoring the attenuator altogether as dmp suggests. It'd be silly to have the pot in circuit all the time, even just from a user interface perspective (annoying if accidentally nudged/moved, etc).

In reality, I never, ever, ever switch the attenuator in. I have built two Wolfboxes with vintage Triad transformers, and I included the attenuator on both just because... but it is always in bypass.

Thanks for chiming in and the information all.
I will build it with the pot being able to be bypassed.
This particular DI has a filter switch which acts as a hi-pass type filter.
I’m thinking I would change it to a lo-pass type to filter out riz as opposed to rumble.
Thoughts?

I wouldn't want a filter in a DI if using it for recording.
Definitely a ground lift

one of the best passive di's we have at the studio is a pair of westlake audio direct boxes. unlike the typical orange ones a person would see with the westlake logo, these are built out of large electrical boxes. they have a ground lift switch, the standard 1/4" and thru jack, and they have both xlr male and female connections We use them quite regularly to run guitars from the control room to the live room with one d.i. box through the patchbay and then the second d.i. connecting from the live room mic panel to get is back to 1/4" and into an amp. The change in sonic is not enough to be a problem If you are doing a passive design, the duel xlr works really well.

I am thinking of building this box with a CAPI CA11 transformer. Would this work and where would I find a wiring diagram? I am not new to soldering but am new to reading schematics etc.

Just wrapped the build for a dual channel Wolfbox.
I used a pair of Triad A11 J reissue transformers and I think they sound fantastic. I was able to compare it to our DI that has a Sowter 1585. Although I was not expecting to hear a serious difference, I really found that the harmonic representation on this one was significantly superior.
Just for the fun of it, I tried decoupage as my enclosure design. I really wanted to wrap it with aged sheet music. For any custom artwork, I printed it on white paper and aged it, myself and coffee.
I love the way this one came out.