Passive or Active DI?

elenore19

Slowing becoming un-noob.
What is the difference? Which one should I go with? The passive seems to be cheaper. So that's a plus.

Any suggestions?


-Elliot
 
My personal experience has been that the active DI's are generally much nicer to deal with. For acoustic instruments (e.g. guitars), it's hands down in favor of the active DI. Something like a keyboard/drum might be not as dramatic.

My experience has been with both recording and live sound.

Even a $75 active Behringer will be better than a $100 passive whatever.

My guess is that the active electronics allow the DI to do things that a simple passive transformer can't do on it's own. The "things" I refer to would be give you better sound quality across all frequencies, volumes, etc.

The one thing I hate about a lot of DI's is that they are sort of black boxes - many only have inputs/outputs and no knobs to play with... and that sucks in my book :p If you spend extra money on something, it should have more knobs and shit on it.

Lights are cool also.
 
di

it depends what kind of instrument... say you're using an active instrument (a bass or a guitar with active electronics-the kind you need a 9v battery for) then you'd use a passive DI, and if you're using an instrument w/ active electronics then you need a passive DI. GB - kRiS
 
My personal experience has been that the active DI's are generally much nicer to deal with. For acoustic instruments (e.g. guitars), it's hands down in favor of the active DI. Something like a keyboard/drum might be not as dramatic.

My experience has been with both recording and live sound.

Even a $75 active Behringer will be better than a $100 passive whatever.

My guess is that the active electronics allow the DI to do things that a simple passive transformer can't do on it's own. The "things" I refer to would be give you better sound quality across all frequencies, volumes, etc.

The one thing I hate about a lot of DI's is that they are sort of black boxes - many only have inputs/outputs and no knobs to play with... and that sucks in my book :p If you spend extra money on something, it should have more knobs and shit on it.

Lights are cool also.
What?
makes no sense... Active DI's have an amplifier (transistors or vacuum tubes & power supply (which can be batteries)) for buffering output & input impedance of the devises to be connected so it's possible to have no signal level loss when connecting a devise with a low input impedance to a devise with a higher output impedance. Basically the input impedance to the active DI is very high so it can't load down the signal that's input to it & the DI's output impedance is very low so the input impedance of the devise it drives can't load down it's signal output. They can come with various degrees of options for interconnect such as balanced or unbalanced outs, convert unbalanced in to balanced out or -10/-20 dB pad out etc..

Passive DI's have no amplifier (aka. active components like transistors or vacuum tubes & power supply) & can only match high impedance devises to low impedance devises via a transformer which will also shift the amplitude level of the signal down proportionately when going out from a high impedance into a low impedance (and visa versa). It can also convert unbalanced to balanced via transformer.

Active DI's are more versatile because of their ability to interconnect devises of all impedance levels & even output one devise to several inputs without signal loading (signal level loss), but sometimes a passive DI is all that's needed if for instance a level shift is desirable as in going from a line level unbalanced out to a low mic level balanced input.

Course, I could be wrong, but I'm not
http://www.wikirecording.org/DI_box
 
it depends what kind of instrument... say you're using an active instrument (a bass or a guitar with active electronics-the kind you need a 9v battery for) then you'd use a passive DI, and if you're using an instrument w/ active electronics then you need a passive DI. GB - kRiS

This was the standard mantra for a long time, because with active instruments and things like keyboards it was really easy to clip older active DIs, which sounds like shit. Passive DIs would just saturate. But passive DIs can load down passive pickups, affecting tone, and have around 20db signal loss. Today's active DIs can handle much hotter signals, but still require power from the wall, batteries, or phantom power.:)
 
I used to do active but I switched to passive and I prefer it overwhelmingly. I set the transformer ratio very high to keep the pickups unloaded, and it sounds great, good response with that extra trafo mojo.

You really can't beat passive headroom easily or cheaply; a passive box should be able to do +22dBu (or more) without trouble, whereas a phantom-powered or battery-powered box would struggle at that level, unless it padded the input which is generally not what you want to do. The Behri is spec'ed at +10dBu input without the pad. With the -20dB pad, it would have -90dBu noise, compared with a passive -20dB transformer feeding a -125dBu mic preamp, that's -105dBu equivalent noise, or 15dB better headroom (ignoring added noise in the trafo, which should be small).
 
I used to do active but I switched to passive and I prefer it overwhelmingly. I set the transformer ratio very high to keep the pickups unloaded, and it sounds great, good response with that extra trafo mojo.

You really can't beat passive headroom easily or cheaply; a passive box should be able to do +22dBu (or more) without trouble, whereas a phantom-powered or battery-powered box would struggle at that level, unless it padded the input which is generally not what you want to do. The Behri is spec'ed at +10dBu input without the pad. With the -20dB pad, it would have -90dBu noise, compared with a passive -20dB transformer feeding a -125dBu mic preamp, that's -105dBu equivalent noise, or 15dB better headroom (ignoring added noise in the trafo, which should be small).

Elliot,

The technical stuff is probably what you wanted to avoid in the first place. Cost wise, you're talking $30 vs $50 (passive vs. active). If you can swing it, you should probably get the active just to give you more flexibility.

But it won't sound like shit or be the end of the world if you go passive.

See if you can borrow one of each from a music store and then do an a/b with your own equipment. That'll tell you the real answer for your situation.

Not to diss anyone. But we get soooo hung up on specs/numbers/settings around here that we forget that we're here to make music.
 
Not to diss anyone. But we get soooo hung up on specs/numbers/settings around here that we forget that we're here to make music.

Uh, you were the one who said you wanted "knobs and shit". What does that have to do with making music? And if you aren't worried about specs, then just plug your guitar straight into a converter. What, the impedance is mismatched? Sorry, that's a spec, can't help you.

An active DI should be cheaper than a passive DI, because the parts in an active are much cheaper than a good transformer. But the Behri, for example, has an active front end and an output transformer. That's not a bad idea, but if it sells for $75, what does that say for its likely quality vs. a strictly passive DI at $100? I'd rather pay the money for a better transformer and skip the $0.20 opamp.

Seriously, I can build an active DI for about $6 in parts. $5 of that is the connectors . . . it won't have knobs or shit, but then it doesn't really need them to make music, does it?
 
..
Even a $75 active Behringer will be better than a $100 passive whatever.,.

Whoa... you made me back away from the keyboard before lightning hit it...

I have both active and passive boxes and prefer the active, probably having to do with how close the incoming signal is to a line level signal. But I also have a handful of Behringer active boxes / splitters - and they are quirky. Sometimes phantom power injects noise, sometimes not. My Carvin passive box has one advantage in that it is generally stone quiet.

But hey - more wrenches in the toolbox as far as I can see. They've bailed my butt out a few times. I'd love to get some Radial boxes.
 
Whoa... you made me back away from the keyboard before lightning hit it...

I have both active and passive boxes and prefer the active, probably having to do with how close the incoming signal is to a line level signal. But I also have a handful of Behringer active boxes / splitters - and they are quirky. Sometimes phantom power injects noise, sometimes not. My Carvin passive box has one advantage in that it is generally stone quiet.

But hey - more wrenches in the toolbox as far as I can see. They've bailed my butt out a few times. I'd love to get some Radial boxes.

I have a Baggs active DI. Acoustic guitars sound great through it. Basses make it distort.
 
I have a Baggs active DI. Acoustic guitars sound great through it. Basses make it distort.

I use the L.R. Baggs Pre-amp/DI at church. If it's the same one I have, it really is top of the line sound quality. I got mine used for about $125. But then it does have the knobs and switches (and even a little light) that I referred to above - that alone makes it sound better ;)

If your bass is making it distort, you could turn down the gain some.

But again, that's 125 (active) vs. 30 (passive).

Elliot, Here's another thing to consider if you haven't already... If you're using an acoustic amp, it might have a DI built into it anyway! But you didn't say you did, so I"m guessing you don't.
 
I use the L.R. Baggs Pre-amp/DI at church. If it's the same one I have, it really is top of the line sound quality.

That's the one.


If your bass is making it distort, you could turn down the gain some.

Tried that, but the distortion is coming in on the front end. It distorts with my passive as well as my active basses, too. I could turn down the volume on the bass, but for recording I like to have it all the way up so I don't have to worry about bumping the volume and then trying to get it back exactly where it was.
 
What is the difference? Which one should I go with? The passive seems to be cheaper. So that's a plus.

Any suggestions?


-Elliot

Go Passive.

A DI box converts an unbalanced, high impedance signal (the kind of signal generated by most pickups and contact mics) into a balanced, low impedance signal (the kind of signal required by most desks). It also isolates the output signal from the input signal (and most also incorporate an earth lift facility), so it can be used - as a temporary measure in an emergency - to cure ground loop problems in other parts of the signal chain (e.g. between desk and power amplifier).
Active DI boxes use electronic circuits to convert and isolate the output signal from the input signal. For this reason, they always require power. Most active DI boxes use batteries - usually 9V PP3 - or phantom power (our own can use either source). However, some DI boxes cannot run on phantom power (i.e. they need batteries), and some cannot use batteries (i.e. they won't work unless the desk can supply phantom power). A few varieties will run from separate power supply units.

Passive DI boxes use transformers to convert and isolate the output signal from the input signal. They are cheaper than active DI boxes, and do not require any power. However, the reactance of a transformer increases as frequency rises, so most passive DI boxes will exhibit some high-frequency signal loss. In all but the cheapest passive DI boxes this will not greatly affect the signal within its useful range, and the degree of difference is comparable with the difference between dynamic and condenser microphones.
 
Glad I found this thread, I've been looking at the passive Baggs pick ups and am about an inch away from ordering one. Just wanted to get some insight into passive or active.

I recently caught a couple of Wilco shows and noticed Jeff had one in each of his acoustics, I LOVE the sound but I also know that he has an absolute ocean of pedals at his feet so wasn't sure if what I was hearing was ALL just guitar/pick up/amp. Anyone have any info?

Waiting on my copy of the "Sunken Treasure" DVD to get here, figured I could probably hear/see more on that. ;)
 
I went with both an active pick-up (Baggs) and active DI (also Baggs). The active DI has eq as well as the regular DI stuff. I've never seen any passive DI that had eq capabilities.
 
I went with both an active pick-up (Baggs) and active DI (also Baggs). The active DI has eq as well as the regular DI stuff. I've never seen any passive DI that had eq capabilities.
and using Eq on an active DI is a sound engineers nightmare.
also if you have active pups you don't need an active DI FWIW you dont need a active DI period.
 
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