Suggestions for passive DI box

[Chris Hales]

On 18/10/2025 at 02:10, PinkMohawk said:

That's a slick little design you've got! I just had a look over the manual you posted, I like the look of it a lot. So personally, I have two use-cases for DI's, when I'm performing, and when I'm running the desk. There's no overlap for me, I'm not in a band where I have to run out to mix the show while I'm playing it. 

When I'm performing, right now my DI boxes go at the end of the chain, kicking the parallel to any amps I might be running, with the XLR's going straight to FOH after all of my effects which are relatively simple, mainly heavy drive, amp sim, sometimes pitch effects. That'll change when I finally make the switch to an Anagram, where I'll be splitting the outputs internal to the pedal, using the XLR outs to go to FOH with amp sims, and the 1/4" outs to go to amps, before any amp sim on the pedal. 

When I'm on the desk mixing a show, DI's are right before the amps as well, and I leave it to the performer to put whatever they want in front of them. For me, the name of the game is reliability. I need to know that when I bring that fader up, I'm getting sound, and it sounds like the player. If I need to tweak things, I usually have some form of EQ on the desk, whether it's a basic analogue channel strip or a full graphic EQ on a digital desk. That said, giving the player a little control over their DI tone with that shaping knob is a great idea, letting them adjust what they're getting out of the monitors a little without trashing what I'm getting at the desk. 

If I could add my two cents to your current design? As a player who'd mount this to my board, I'd love to see all the inputs and outputs on one side of the pedal. That's just a personal preference, I like having my 'final stage' on the pedalboard to be like that. As an engineer who'd throw this in my pelican for a gig, I'd love to see the controls be turned into something low profile. Trim pots accessible through the enclosure, etc. This is an organisational thing. Engineers often carry DI's in their pelican cases (I've got three of the most basic, passive DI's I could find in mine as my emergency DI's.) and it's already tight for space in there. Having the enclosure as low-profile as possible, with as few things sticking out as possible would make it that much more tempting to have these as my go-to DI's instead. 

Hope this all helps!

Thanks so much for the useful and detailed feedback - plenty of food for thought there!

One thing I hadn't considered is that people might be using the DI out and instrument level out at the same time.  I think I'd have to add a transformer to the DI out for that to be guaranteed hum free.

The shaping control currently affects all outputs, but i think you're suggesting it would be more useful affecting the DI output only.  One of the challenges I had with this pedal was keeping the current consumption low enough that it could be phantom powered, but I think I could manage that without affecting anything.

Good shout regarding the rotary controls.  You used to be able to get pots with removable knobs, so I could probably used those to cover both bases (haha!).  Would having the footswitch sticking out present a problem, though?  I don't think I have the resource to engineer a slick Boss style footswitch to this thing!

Going back to passive DIs, which seem to be everyone's preferred option, do you not find these affect the tone - if there are no preceeding effects pedals, anyway? One thing I feel is important is to present the instrument with a high impedance (my prototypes present about 660k, which is already lower than the 1M I'd usually aim for).  A passive DI would present around a tenth of this, which I reckon is much too low for a passive instrument.

Thanks again for your really constructive input

 

Chis

[Chris Hales]

On 03/10/2025 at 10:29, Jack said:

If you ever run your passive bass straight into a passive DI, or indeed through some true bypass pedals that are not engaged, then there is a chance that the passive di box will load the pickups on the passive bass down to a point where this can be heard. If you can hear it, then there is a chance that you do not like the tonal change. The physics is a given but whether it's audible depends on the pickups and the di, and whether it's a bad change depends on the player. 

 

 

One thing I'd chip in is that with a passive bass a passive DI is likely to affect how your tone and volume controls react.  With everything full up the effect might be minimal, but probably not otherwise.  

I hope this isn't a stupid question, but if you're happy runing an (active) effects chain, why not an active DI as well?

 

[Jack]

2 hours ago, Chris Hales said:

One thing I'd chip in is that with a passive bass a passive DI is likely to affect how your tone and volume controls react.  With everything full up the effect might be minimal, but probably not otherwise.  

I hope this isn't a stupid question, but if you're happy runing an (active) effects chain, why not an active DI as well?

 

I've got no problems with an active DI at all, I've got problems with 9v batteries going dead and the lack of phantom power at my (admittedly bottom feeder) level. My preferred solution would be a DI that ran from boss style power like other pedals. I actually built one using a prefab board, and I own the Harley Benton too, as well as the usual pedal preamps that also include an XLR output like the Sansamp.