DI Box advise for Ultralite mk5

[Rubens]

Hi there!
I got a mono external preamp that I am connecting to the Ultralite mk5. In order to record vocal and electric guitar without messing with cables I need a DI Box. It seems that not every DI were created equal, that the transformers are important to take in consideration and even the metal material of the box etc.
Is an unanimous understanding that the RAID JDI is the one that works better?

Thank you,
Rubens

[mikehalloran]

Hi there!
I got a mono external preamp that I am connecting to the Ultralite mk5. In order to record vocal and electric guitar without messing with cables I need a DI Box. It seems that not every DI were created equal, that the transformers are important to take in consideration and even the metal material of the box etc.
Is an unanimous understanding that the RAID JDI is the one that works better?

Thank you,
Rubens

You have those two CombiJacks on the front. Either handles a mic (XLR) or an instrument level (TRS) plug. No DI necessary if recording 2 mics, 2 instruments or 1+1 of each. From the User Guide:

3. Individual preamp gain, switchable 48V phantom
power, and optional -20 dB pad switches for each
combo input. The Precision Digital Gain™ knob provides
+74 dB of preamp gain or instrument input gain. Both
gain settings are retained independently. Turn the knob
to see the gain adjustments in the screen.
…
The Precision Digital Gain™ knobs on the
front panel for each mic/instrument input provide
up to 74 dB of boost in precise 1 dB increments.

Your Line Inputs 3–8 may need a DI if 20dB isn't enough.

Line In
Connector Type 1/4” Female, TRS Balanced/unbalanced, Tip hot
Specification Complies with EBU-R68 / SMPTE RP-155
Impedance Load 20 k ohm balanced
Dynamic Range 120 dB A-weighted
THD+N -113 dB 1 kHz, 24 dBu, unweighted, unity gain
Frequency Response ±0.05 dB, 20 Hz/20 kHz Ref. 1 kHz
Max Level In +24 dBu
Gain Range 0 to +20 dB Digitally controlled in 1 dB steps

If you need additional Instrument level inputs, a DI is usually necessary. What to get depends on what you want to plug in but there are excellent passive stereo boxes out there. With transformer DIs, you will hear that better ones have better bass (basses, keyboards, electronic drums, synths etc.). All the marketing mumbo-jumbo doesn't mean a thing if you get a chance to check them out in person—listen to the bottom end.

Active DIs give you more control and are often necessary if the signals are weak. There's an old adage that one should pair passive DIs with active pickups and active DIs with passive pickups. The truth is that Active DIs work with just about everything but a good Passive DI doesn't need power and may be exactly right for your situation. I have both. Radial is a good brand but so are many others.

If you need to add more microphones, you will need a mic preamp. Most will also function as a DI.

In both cases, you have a huge number of choices ranging from single eight channels. The cheap stuff is usually crap but some of the inexpensive stuff is quite good.

So, what are you looking to hook up?

[Rubens]

Hi Mike,

I have one mono preamp with 1 in and 1 out heading to the Ultralite and mic respectively. (1 cable to the Ultralite out another to the mic/instrument) If I want to record with the mic, the cable that comes from the preamp must be plug in the mic, if I want the guitar I have to change to the guitar. I am planning not to mess with cabling, that is why I believe I need the DI.
I shouldn't plug from the preamp to the Ultralite ins. The idea is to use the external preamp. So again, external preamp mono to the Ultralite out only.
I need a passive DI box. Electric guitar and mic. No more than those 2 instruments.
Is the Radial JDI the one to be taken or something else?

[daniel.sneed]

Hi Rubens.

AFAIK, Ultralight inputs 1 & 2 are mic/instr inputs, while inputs 3, 4, 5, ... 8 are line inputs only.
That's great, but many options may bring confusion.

For singing, you may just connect your preamp out to Ultralight input 3 and you're done.
No Di required.

For your electric guitar you have three options:
- use a guitar amp, and set a mike in front of it (same connection as singing mike but input 4, or just use Ultralight input 2 with xlr cable).
- record your guitar dry plugged in Ultralight input 1 with mono jack cable. And set an amp sim plugin in your daw (DP has good ones, third party brands too).
- record your guitar with a pedalboard with amp sim included (not all of them have such amp sim option). In that case pedalboard is plugged in Ultralight 1 with mono jack cable.
Again, no Di required for all of the 3 options.

IMOE, in case I want (for some reasons) use an external mic preamp for singing (or whatever):
- I connect the mic to preamp mic in (xlrF-xlrM cable)
- I connect preamp line out to interface line in (jack-jack, or xlr-xlr, or xlr-jack, as long it is a 3 wires type, called balanced cable)

Sure, I would never connect a preamp out to an interface mic in.
Unless I'm looking for adding noise and/or distorsion.

[mikehalloran]

What Daniel says.

For singing, you may just connect your preamp out to Ultralight input 3 and you're done.
No Di required.

Sure, I would never connect a preamp out to an interface mic in.
Unless I'm looking for adding noise and/or distortion.

Also, try plugging your mic straight into Inputs 1 or 2. The mic preamps that MOTU use are quite good with up to 79 dB gain and available phantom power. Since your stated goal was live performance with few cables, you should try this.

[Rubens]

Thank you for the answers. I am though only looking for advise to achieve a DI box. I know how the Ultralite works, it is my third one since 2006, and I want to record both vocals and electric guitar through the external preamp. I understood that you were trying to help me out with new perspectives but... I just needed a DI box, as written on the first message, and to know if the Radial have a competitor.


Anyway, I have solved the case.

Thank you

[Phil O]

If you are looking for a passive unit I highly recommend something that uses a Jensen transformer. The Radial JDI is one that does. If you're handy with electronics you can build your own. Here's a simple passive schematic from the Jensen site:

https://www.jensen-transformers.com/wp- ... /as066.pdf

I have built 2 of these and they work great. I've also used Jensen transformers in other units that I've designed and always had great results. (Yes I'm a Jensen fan.)

If you're looking for something active, I personally like this one:
https://www.sweetwater.com/store/detail ... talog%20Ad

I don't own one but I've used one in a friend's studio and it sounds great. The Radial stuff is pricey though.

Your friendly neighborhood Phil

[bayswater]

If you are looking for a passive unit I highly recommend something that uses a Jensen transformer. The Radial JDI is one that does. If you're handy with electronics you can build your own. Here's a simple passive schematic from the Jensen site:

https://www.jensen-transformers.com/wp- ... /as066.pdf

I have built 2 of these and they work great. I've also used Jensen transformers in other units that I've designed and always had great results. (Yes I'm a Jensen fan.)

The Radial JDI is not likely to lead to any regrets. I have two on a patch bay and use them for a lot of things.

Phil, do you recall the difference in the cost of buying from Radial versus making your own using the design you posted?

[mikehalloran]

Jensen makes many transformers to many specifications and Radial is one of many companies that use them in some products. Likewise, Radial makes a large range of passive and active DIs — I have some of each.

Without knowing your specific need—which you have not told us—it's impossible to recommend anything in particular.

[Phil O]

Phil, do you recall the difference in the cost of buying from Radial versus making your own using the design you posted?

Here's the transformer I used:

https://www.markertek.com/product/jt-db ... ransformer

I think it was about 10 bucks cheaper back then. I used a cast aluminum prototype box. I think it was about 15 bucks.

Whole thing came in at about $100 as I recall. I did however leave out the pad and high cut filter, and some of the parts I already had on hand.

BTW, I also built a phantom powered, active version of this (my own design) utilizing a TL081 op amp.

The Radial JDI currently is at about $250 at Sweetwater.


Your friendly neighborhood Phil

[bayswater]

The Radial JDI currently is at about $250 at Sweetwater.


Your friendly neighborhood Phil

Thanks Phil. I’ve seen it recently for $199 (Canadian) but looks like making your own is pretty easy and economical.

[mikehalloran]

The Radial JDI currently is at about $250 at Sweetwater.


Your friendly neighborhood Phil

Thanks Phil. I’ve seen it recently for $199 (Canadian) …

I would hope so since Radial is a Canadian company HQ'd in Vancouver BC. Maybe they have an outlet store near you?

Here is the spec sheet for the JT-DB-E. Properly loaded, ruler flat from 20–20kHz ( -1dB is 2–50k). Nothing wrong with that.
https://www.jensen-transformers.com/wp- ... t-db-e.pdf

The JT-DB-EPC, used in the Radial JDI appears to be the same except the leads are pins for a board mount.

I have one of those in my wife's keyboard bag for when she has to bring it to gigs — stereo is never necessary for that. I have no idea what I paid 15 or so years ago. Someday, I should compare it to the Morley MLLS/Ebtech LLS stereo passive DIs that I like so much.… in my free time, of course.

https://www.amazon.com/Morley-MLLS-2-ch ... 08NQ1SMTJ/

The one I have on my desk at the moment is a Radial J+4 active stereo DI. Perfect for transferring cassettes, hooking up my iPad and the occasional extra instrument DI or two (my AIR•192|14 has a pair of instrument DIs built in already). Doesn't say what transformer but it handles the bottom end of an 88 key Yamaha P125 as well as anything else.
https://www.radialeng.com/product/j4

Again, I should set up an A/B/C comparison someday… yea, right.

[bayswater]

I would hope so since Radial is a Canadian company HQ'd in Vancouver BC. Maybe they have an outlet store near you?

That price is in Montreal. The same chain sells it for $299 in Vancouver. Radial is in Coquitlam. They can’t afford Vancouver. The prices are too high.