16 ch passive DI box

[soulitude]

I'm in need of a 16 channel 1U passive DI box, but there's nothing out there on the market so I'm thinking about building one.
Does anyone have a simple solution for this?

We're talking low end here, nothing fancy.

My first thought was to buy 16 pcs of these: https://www.thomann.de/gb/millenium_die_dibox_passiv.htm and then put all what's inside of them into a 1U rack but I guess there's an even simpler solution?

Preferably 16 XLRs at the back and 16 TRS/TS on the front to transform 16 unbalanced TS signals to 16 balanced XLR signals.
To fit in something like this: https://www.modushop.biz/site/index.php?route=product/product&path=20_27_61&product_id=52

Happy for any tips!

 

[gridcurrent]

4 Shure M68 microphone mixers, re-wired as passive DI's.

 

[shabtek]

Where are you located?

 

[soulitude]

Where are you located?

Sweden!

4 Shure M68 microphone mixers, re-wired as passive DI's.

Yeah, but I would love it in a 1u rack.

 

[Winetree]

Do want to go active or passive?
Years ago I built an active single I.C, per channel, conversion box.
Unbalanced -10 to +4 balanced and vise versa.
Soldered the I.C. to a perf board and made the connections. I think it needed 15 VDC.

P.S. Just found the box. I.C.s are        PMI SSM
                                                                              2142 P
                                                                              S9310

 

[PRR]

> 16 XLRs at the back

Can you even fit 16 XLR in a 14 inch rack box?

The key special part is the transformer. If the Thomann product works acceptably, you won't find a better deal than 10 bucks a piece, so you may as well buy a a crate and start tinkering.

 

[Winetree]

> 16 XLRs at the back

Can you even fit 16 XLR in a 14 inch rack box?

The key special part is the transformer. If the Thomann product works acceptably, you won't find a better deal than 10 bucks a piece, so you may as well buy a a crate and start tinkering.

I agree. But I've found that cheap D.I. boxes have a 10 cent transformer inside.
What's that going to do to the sound. All our studio D.I.s have Jensen transformers or are active.

 

[soulitude]

Yeah, those transformers are probably crap. But people that've bought seems to think they don't change the sound too much.

I just love the idea of fitting at least 14 channels in a 15 cm deep 1U case. Would be portable and easy.
It'd be convenient to buy ready made front panels with holes for 16 XLRs. Like this: http://www.allmetalparts.co.uk/1u-punched-hole-panels/77-1u-16-xlr-d-front-panel-5055726202004.html#

It's a shame I don't have one of those cheap D.I.s here to open up and see what's inside. Don't know how much space each channel would take. Do you think they could be interfering with each other if they'd be in there side by side?

 

[gyraf]

I'm in need of a 16 channel 1U passive DI box

Why is the need for passive?

Why is the need for 1u?

Answers to those two are probably necessary to give you good advice, or at least cut the best compromise.

Jakob E.

 

[joaquins]

Why is the need for passive?

Why is the need for 1u?

Answers to those two are probably necessary to give you good advice, or at least cut the best compromise.

Jakob E.

Why is the need for 16? I've been working with relatively big rigs and never seen even close to 16 DI on the stage. Also the output could be DB25 I guess, since fitting that many XLRs on the back is a tight task.

JS

 

[soulitude]

Why is the need for passive?

Why is the need for 1u?

I just figured the components for a passive D.I. would be slightly cheaper than an active D.I. - and it'd be only used for synths and other sources that doesn't necessarily need active.

There's no real need for a 1u rack case - basically the only thing I'm trying to figure  out is how to make a 14-16 channel D.I. box that's affordable and most of all portable. As small as possible. Since the only pre-made things I can think of is the low end 8 channel 1u racks - I thought I might as well try to fit more channels in an even smaller box.

Why is the need for 16? I've been working with relatively big rigs and never seen even close to 16 DI on the stage. Also the output could be DB25 I guess, since fitting that many XLRs on the back is a tight task.

It's for a synth/computer rig that needs 13 channels. So 13 would do. And yes, DB25 could be good!

 

[gyraf]

So passive/active is a matter of price. And again, for a passive to be good, you need expensive transformers. So you need to decide on the price/quality compromise.

Active DI-box can be done relatively cheaply, depending on what you really need it for, e.g.:

(yes, it's a splitter - but high Zin, low Zout: linedriver)

..So the real question is:

What do you need it for? As detailed as possible please, if we should have a chance of helping you with the compromise..

Jakob E.

 

[Markus_Krippner]

Using Neutrik A-Series Panel Connectors (instead of D-Series) 16 XLRs will fit on a 1U/19inch rear Panel.
It's tight, but it will fit. And they're much more cheaper ;-)

http://www.neutrik.de/de-de/xlr/a-serie/nc3mav

...markus

 

[CJ]

write down what you are going to plug into this box,

you might want to change transformers depending on if you use guitar on ch 1 and keys on ch 9,

ProCo makes a quad DI unit,

http://www.procosound.com/interface-devices/direct-boxes

 

[ruffrecords]

A lot depends on the sources. If they are all line level synths and the like then you know the signal levels are line levels and the output impedances are relatively low. All you then need is a 10K:600 transformer per channel. If it is in a steel box and the inputs are line levels then the transformer probably does not even need to be screened so one of Edcor's range of low cost transformers would do the job. Transformers have their limitations but their great advantage in a gigging situation is they provide galvanic isolation so you can always eliminate hum loops.

Cheers

Ian

 

[abbey road d enfer]

I'm in need of a 16 channel 1U passive DI box, but there's nothing out there on the market so I'm thinking about building one.

A $10 DI xfmr is crap, a $10 active DI is excellent.

Does anyone have a simple solution for this?

OPA2134 unity-gain, impedance balanced outputs, 24mm-pitch Neutrik sockets.

 

[soulitude]

I kind of disappeared from my own thread here, but now I'm back.

The setup is as following:

9 channels coming from a  LP-16 backing tracks player. Unbalanced outputs.

4 channels (stereo bass and stereo synth) coming from a MacBook via an audio interface with balanced outputs.

I just want to have a space saving, simple setup where I've got all these channels going through DIs so I don't need to set that up on stage. Portability is a big factor - otherwise I would have bought two Behringer DI800 and be good to go. Affordability is the other factor (when competing with that cheap Behringer stuff).
The audio interface outputs are balanced, but sound engineers always run them through DIs on stage.

I want to give the sound engineer a XLR snake with all these 13 channels ready to plug in to a stage box.

 

[Lipaz]

Well, topic owner disappeared for 17 days and no response one given since 27 Feb 2017.

Here is the solution, if someone is still interested in 16ch DI box. How good it is as a passive DI in such a small scale, I do not know:

MAM 16 DI

 

[abbey road d enfer]

As hinted at in the product page, it's appropriate for synth and other line level sources. I believe that's what the OP was interested in. tMO passive DI boxes are no good for passive guitars.

 

[silsila]

I use a racked passive DI, but with only four ins/outs in our studio. It is a really useful bit of kit.
I would definitely agree that guitars are too high impedance for the transformers unless buffered with something prior. Passive basses sound fine though.
The transformers themselves are not super high quality in the box I have - it’s a Proel and cost me 35 euros second hand.
I’ve tested them and they make practically no difference to the sound until it starts getting too loud for them, then they distort nastily! Luckily, that’s at a much higher level than needed.
When I need a more elegant D.I I use a couple of external boxes where I replaced the xformer with something a bit more elegant.
So yeah, if you watch the gain, even fairly cheap units like this would prob be fine unless super critical.
If I needed 16, I would buy ready made products and replace the transformers in some or all of the channels where necessary - that way you get the rack, switches, connectors etc already done.