Passinwind
Well-known member
Cool, looking forward to seeing that datasheet and more info on applications as you get to it.
DIY Direct Box?
- Thread starter Ginsly
- Start date
fontoponto
Well-known member
Feral Feline
Well-known member
Fretless
Member
I like the sound of this. Similar shielding?
vigilante398
Authorized Vendor
Yessir, nickel steel housing.
Ginsly
Well-known member
Excellent, thank you! I’ll check it out for sure. The goal is to build a nice passive DI and an active box (for acoustic instruments with passive transducers). It’d be great to have one switchable box, but I think that’s a little beyond me…
xefned
Well-known member
Very cool.
I have the old layout from a Countryman DI, but it requires a transformer.
I might just build yours instead since all the parts look common and inexpensive. Thanks for posting it!
Ginsly
Well-known member
Would you mind sharing the layout for the Countryman? Those are great DIs! Active or Passive?
owlexifry
Well-known member
would also be interested.
got a Jensen JT-DB-E i’ve been sitting on for a few years . need a good circuit for it
xefned
Well-known member
It's the good 'ol "country hick" project that's been online since 2004 (!!).
I found some modifications on free stompboxes and elsewhere online. When I built one in 2012, I used an inexpensive OEP A262A2E transformer.
The original tracer removed the phantom-powered circuitry and posted a battery-powered version. But I wanted mine to work on phantom power, so I stuck some 37k resistors on pins 2 and 3 of the XLR and ran the other ends of the resistors to the positive rail. Amazingly enough, that worked, and it delivers 10vDC when phantom power is applied.
Ginsly
Well-known member
Excellent, thanks! Hmm I don't etch my own boards or anything, so I'll look around and see if anyone's done this on Vero...
I actually like dual-9v DI operation (VERY little draw), so hopefully I can find a pretty straightforward version of the Hick to build!
xefned
Well-known member
I could lay out a PCB pretty quickly, but I don't know how many people would be interested in using the OEP transformer. I think they're only for sale in the UK. What transformer are you planning to use?
I think Niki from N-Audio laid out the original circuit board for the OEP.
Here's how mine turned out. I'll probably leave off the amp source switch if I build another.
I think Niki from N-Audio laid out the original circuit board for the OEP.
Here's how mine turned out. I'll probably leave off the amp source switch if I build another.
Ginsly
Well-known member
Whoa! Very nice!
Like I had mentioned, I'd ideally set it up for 2x9v battery operation rather than phantom, although I realize that may seem silly. Both would be great, but I'm not sure that's possible...
I'll (hopefully) be using a transformer from @vigilante398, but I can't give you specifics of it I'm afraid... It's a Unagi Magnetics E4305 DI transformer.
So- since the Countryman 85 has a transformer, can it be used as a passive box as well? Kind of like the Warm Audio active/passive box?
Feral Feline
Well-known member
Country Hick is cool, thanks for that, @xefned.
It lead me to this JLM as well...
Basic Schematic
Phantom or battery powered DI
Phantom or battery powered DI with output transformer
JLM is still in operation.
It lead me to this JLM as well...
Basic Schematic
Phantom or battery powered DI
Phantom or battery powered DI with output transformer
JLM is still in operation.
xefned
Well-known member
No, the Countryman always needs voltage to drive the fet. The transformer is just a 2:1 ratio.
The Unagi Magnetics E4305 (I'm guessing) is probably a higher-quality transformer since it's $62 compared to the $16 of the OEP clone, the Vigortronix VTX-101-002.
I'll still build another cheap country hick because I still have a leftover self-etched board, but I'll always wonder if it sounds noticeably worse than a higher-quality transformer.
It's OK. I have a recording project underway and I'd rather be recording than fretting about sound quality.Let us know how the Unagi works out.
Ginsly
Well-known member
Gotcha. As much as I'd love a 2-in-1 I think I'll wind up with both a passive and an active once I land on the right layouts.
Ginsly
Well-known member
In thinking about it, aside from a DI what I really need is a preamp for passive acoustic transducer piezos. The K&K Pure Preamp seems to be fairly simple and (should be) a good match for most of my passive instruments. I like that it runs on a battery, too. The only schematic I could find was on this Youtube video. In the comments someone mentions that their schematic swaps the Bass and Treble controls - I wonder if it's just the LABELS for Bass and Treble that are swapped, and not any components..? Below are some images from the vid.
I haven't plotted perfboard or vero from schematics yet, so this is kind of a big project for me. I have no idea where to start, honestly. To complicate things, I also have an excellent transformer-based DI/XLR module (by local saint @vigilante398!) that I'd love to incorporate. It would be nice to have a box that was a K&K preamp > passive transformer-based DI all in one, with the option to switch out the preamp and just have a passive DI.
Is this crazy? If not, I could really use some advice!
I haven't plotted perfboard or vero from schematics yet, so this is kind of a big project for me. I have no idea where to start, honestly. To complicate things, I also have an excellent transformer-based DI/XLR module (by local saint @vigilante398!) that I'd love to incorporate. It would be nice to have a box that was a K&K preamp > passive transformer-based DI all in one, with the option to switch out the preamp and just have a passive DI.
Is this crazy? If not, I could really use some advice!
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