Will this schematic work with 1/4 watt resistors?
The schematic suggests using 0,5w resistors, but I've build two of these with 1/4w resistors that are working just fine.
Is threre a way to power this with a 9V power source instead of phantom power?
This layout would need to be changed a bit to run it from a 9V battery. But there are a couple of vero layouts of the same DI circuit but with battery only on the tagboard effects forum. So have a look there in the contributions section and you should find it. Cheers / Fredrik
See the schematic for a dual powered Active DI at this link:
https://sound-au.com/project35.htm Note that it is slightly different from the original board layout specified here. Note the values for C4 & C5 as well as for R13 which has a different purpose than limiting the current into a LED to show that power is on. You might also consider using a "Center Off" type of switch if you are using a pair of batteries to power the Active Direct Injection device.
Can I just wire a second mono jack in parallel to the input to have a link-out-jack? Any problems about this, signal oder treble loss?
Thanks in advance!
Yes, that's how many DI's are wired up so it should be fine. :)
How does this get powered off of phantom, instrument gets plugged through input and the XLR is the output to the board or recorder, I am hoping someone can guide me ?
Hi S Beblis,
The XLR output is also the phantom power connection and should be connected to the XLR mic input of your audio interface or mixer. Most modern audio interfaces or mixers can supply phantom power via the mix inputs..
So instrument gets plugged into circuit and xlr to interface input and phantom power needs to turned on , on that particular channel, is that correct? Thank you again, appreciate it
That's correct :)
The original Schematic from Rod Elliott had R4 & R5 listed as: 10K. Your project shows: 100K. Is that an error?
Sorry, your post missed my radar. R4/R5 is just for the second op amp stage inverter for the balanced output so either 10K or 100K are both ok, as long as both resistors are the same value.
What voltage rating electro caps should be used with this? I know phantom power is 48v, but putting 470uf 100v caps will put a damper on the size of the circuit haha
The actual voltage present at the caps are much lower thanks to the 100R resistors and 24v zener diode, so 50v rated caps should be fine. :)
Fredrik, thank you for the enlightenment! I didn't even think of the 24v zener =X Thank you!
May I add this board after the output of a Sadowsky preamp clone? Do I have to add anything, or just feed the this boards input with the preamp output? Can I just link both the unbalanced tip and the input of this board?
Finally, any chance to get a +9v from this phantom power board to feed the 9v preamp?
Built two boxes with these, along with a Cab Sim, and Runoffgroove Tonemender. Worked great! Although I'm clipping a lot in my input. Was wondering if there was a way to add a PAD toggle and/or Ground Lift?
I may have answered my own question about the Ground Lift. Just put pin 1 on a spst?
Don't listen to me...... Phantom Power comes in from Pin 1 hahaha Don't cut pin 1 =X
I apologize for the slow reply. I've been on tour.
It was a long time since I draw up this layout, so I would have to do some research to be able to answer your questions. I suggest that you check out of Elliot Sound page for more info on his DI box. http://sound.whsites.net/project35.htm
cheers / Fredrik
No problem! I appreciate the reply, nonetheless! Have fun on tour! :D
so anyone actually made a groud lift switch for it??? all i read is that its complex cuz of pin 1 providing phantom power to the circuit.
baouftou, I just read this:
"The earth lift is only fully effective when the transformer circuit is used, and will prove worse than useless in an active unit."
hahaha "worse than useless in an active unit." Pretty strong emphasis! For what it's worth, I've built two of these and never really needed a ground lift. I just figured it would be nice to have one just in case, but looks like the active circuitry takes care of it haha
Jonathon Yi thanks for answering pal!
Well i've understood perfectly the sequence on why we cant ground lift this DI box. Still i'm eager to find a sligtly different solution to it just for the reasons of surviving. "Lets say i went to cover a concert with this and suddenly is starts humming and i have no other DI for backup" I'm dead :P
Let me know if you find anything!
haha no worries! I wanted to put one on there for the same reason! Just for the added comfort. That excerpt from the article discouraged me though... haha :(
I'll post whatever I find, here!
As I'm looking to the schematic on http://sound.whsites.net/project35.htm, as I'm saying to me we can lift ground adding a switch on the left down part between VR1 ground pin and the dot right down TL072's pin 4.
On the layboard here, VR1 is absent (as the pad too) but I think we could wire a ground lift switch where "ground" is written.
hehehe. me too!!
You think maybe this with 1/4 watt resistors might give more output than needed?
Hmm... I doubt it. If anything it might introduce more Noise. I've made two of these so far with 1/4 Watt 1% Metal film resistors and everything seems fine. I remember the volume was at unity, but I built this into an EQ/boost pedal, so unity didn't matter much for me haha
Is 4.7 K alright for the LED resistor (I use a standard red 5mm LED)?
Sorry, it’s a low current LED. It’s quite bright, but the brightness is OK for me. The question is: Should I definitely go higher than 4.7 K or can I leave it this way?
If you are ok with the brightness you don't need to change it. Other then having a bright LED it will not be a problem concerning current draw ect, so nothing to worry about. :) cheers / Fredrik
Hello. I'm looking to build one and I ask me how I could add easily a pad attenuator. Is it useful for active bass or guitar pedalboard ?
Sorry, I don't know how to add a PAD to this specific schematic used for this DI box. I've googled and had a look at other active DI schematic, but found nothing that can be directly applied here.
Best regards / Fredrik
Another question : Can I put 2 polarized capacitor of 47uf mounted +- -+ instead of non-polarized 22uf ?
The question could interest someone but I found bipolar 22uf.
It's still a theorical question
In short, yes. :)
Hello. Is there someone who experience a very low sound with a lot of white noise (and resolve it) ?
😕 i built another one this morning and i reached the same result : low sound, big noise. If someone could send me a picture of his board to have a look I didn't mistake in a component orientation. Disappointed, really.
I found on another website that we must use metal film resistors for audio device. I hav some carbon film on my DI Box.
Could it be the reason why ?
Another build one and issue is the same. Are you sure that works ?
Hey Fredrik, not sure if your still watching this thread but I have a question. If the circuit is powered by phantom power thru the XLR, what connects to the Power LED+ row? Do I run a jumper from Pin 1 row to Power LED+ row?
All the layouts are Verified unless noted.
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