Talk:DI unit

message: Nice article. I've added a high quality picture of a passive DI box designed by Cyril Jones. In line with neutral tone, I won't grumble about the inclusion of the Behringer unit whatever I think of their designs. --DavidP 21:10, 6 July 2006 (UTC)
replies: text: Like them or no, their low cost and relatively competent design (and/or thievery of competent design, if that's your preferred word for it) has made Behringer a de facto standard, at least for when "I need it quick, cheap & dirty" applies. If you want something better, you generally already know that you want it. -- Jasper Janssen 15:56, 6 November 2007 (UTC)

message: Maybe it would be useful to explain the reason for using a DI box intead of just plugging the instrument into the "line in" input on the mixing console, which is far easier. I do this always and never have had problems with the signals, no hum, no nothing. I've never needed a DI box.--200.14.108.1 19:19, 18 July 2007 (UTC)
replies: text: Something like a keyboard &c will generally make something close enough to a line signal with low impedance to use directly, but a guitar pickup, for example, will have very high impedance and I think fairly high levels. If your mixer isn't designed for it, things can go Horribly Wrong. Typically it seems you'll find the line inputs on the input strip labeled "Inst" or "inst/line" if they can take a direct instrument input. If you want to inject a high-level low-impedance (speaker and/or headphone) signal, you can quite easily send a regular line input into clipping (most mixers operate their opamps at +- 12-18V powersupply or less, which limits the headroom for high-level in considerably) or even damage it in extreme cases, and a clipped output signal will kill your tweeters at any volume above minimal. In addition guitars (and most other instruments) put out unbalanced signals and for long leads back to the mixing board you greatly prefer a balanced run for resistance to RF interference. -- Jasper Janssen 15:56, 6 November 2007 (UTC)

text: I've found using a passive DI box between a guitar and a mixer mic or line in can help in getting the levels in the right kind of range (and I suspect the freq response is flatter/brighter, but that might just be me...), but usually if I'm going direct I'll have the guitar going into some effect or other anyhow, so I'd just plug that output to line in. Where I have found one indispensable is between a Blofeld synth box and the mixer (with ground lifted), without it there are really high noise levels - can only guess why, but it does the trick.  —Preceding unsigned comment added by Danja (talk • contribs) 19:33, 8 September 2010 (UTC)

text: I have added a paragraph or two under "Purpose" to explain the audio purpose and introduce the electrical purpose.  Russell Cameron Thomas (talk) 21:29, 17 April 2021 (UTC)
thread_title:  Reason for using DI boxes 

message: They don't do impedance matching, which would make source and load impedances equal.  An active DI box does buffering.
A passive DI box uses a transformer to make the impedances like each other, but doesn't make them equal.  I don't know what to call this.  I called it "impedance transformation" for now. — Omegatron 22:32, 8 December 2006 (UTC)
replies: text: The term you are probably looking for is "impedance bridging". I've edited the article to reflect this. --Miken2005 00:16, 24 March 2007 (UTC)
replies: text: Wrong. The impedance of "a mixer input designed for a 100 ohm mic" is not 100 ohms. A mixer input designed for a 100 ohm mic will have an input impedance of at least 10 times that. Thus, your example DI that converts the guitar to 100 ohms is not performing impedance matching because it's being connected to a 1-2k ohm mic input. --Miken2005 (talk) 06:01, 10 February 2011 (UTC)
thread_title:  Impedance matching 

message: This reads like a "how to". It should be completely rewritten for encyclopedic tone. I could see two sentences covering the whole section. Binksternet (talk) 14:10, 22 March 2008 (UTC)
thread_title: Unit Selection section

message: The article on Sgt. Pepper's Lonely Hearts Club Band seems to indicate that DI was invented by Paul McCartney while figuring out interesting things to do with his bass. So 2 questions: 1. Any verifiable proof of this? 2. If so, how to work into article? Lockesdonkey (talk)
:Agreed the history is interesting, but it may not be trivial to source reliably. I've come across Joe Meek as another innovator in the use of DI. --195.137.93.171 (talk) 20:39, 16 June 2013 (UTC)
replies: text: According to this (which is cites Mark Lewisohn's book of the Beatles recording sessions) McCartney seems to have got one of the engineers to build a DI box and Ken Townshend is quoted as saying "“I think direct injection was probably used on Beatles sessions for the first time anywhere in the world”. However the article on the Wolfbox says it was invented in the 1950s. Richerman   (talk) 10:21, 10 April 2016 (UTC)
thread_title:  A little on history 

message: First, in my experience, the term "DI box" is used to refer to several different kinds of devices, including instrument preamps.  While I admit that's a misuse of the term, it's so common it should be addressed.
Second, the opening paragraph says a DI box is intended to convert from line outputs to mic inputs, but then gives as an example an electric guitar.  Passive electric guitars are not line level devices.
There's already enough confusion about this subject!  Please let's not add more.  —Preceding unsigned comment added by 69.134.228.199 (talk) 15:54, 6 September 2008 (UTC)
thread_title:  Please correct the contradictions 

message: I am fairly certain that nobody is going to understand the introduction to this article unless A.) they're an engineer or electrician or B.) they already know what a DI unit is. Please translate from techie to English. It is possible.
Much appreciated, and let me know if I can help.--Atlantictire (talk) 14:56, 8 September 2010 (UTC)
replies: text: I just reviewed the intro as it existed prior to this comment; I'm no EE; I would have been an English major had I matriculated, but, gosh, I don't know that one could put it any simpler. The current version is a bit better but, fortunately, not any less "technical." I believe the meta-comment at the top of the actual article saying it's "too technical" should be removed.
Dogmo1001 (talk) 01:20, 13 February 2011 (UTC)
replies: text: I agree that the intro is just about as simple as it can get for this subject. Removing the tag. Binksternet (talk) 07:23, 13 February 2011 (UTC)
thread_title: Too Technical

message: This article would benefit from a few simple block diagrams showing how DI boxes would be connected in common applications.  — Preceding unsigned comment added by 74.95.43.249 (talk) 22:59, 2 June 2015 (UTC)
thread_title:  A few Diagrams 

message: The section Usage Examples mentions "direct-injection tracking", but doesn't define what that is, nor how it is evident that the songs listed use it.  The article doesn't use that "tracking" terminology at all.  — Preceding unsigned comment added by 98.67.190.147 (talk) 06:03, 5 July 2015 (UTC)
thread_title:  Direct-injection tracking?? 

message: If i look at the formula for transformers (for instance http://www.vias.org/matsch_capmag/matsch_caps_magnetics_chap6_04_04.html ) then the calculation in the History section of this article doesn't make any sense to mr. Not even close. Maybe if someone with proper knowledge could have a look? With my calculations the input impedance, assuming 1500 ohm load, would be 666.66 ohms. If i'm correct it would mean most of the History paragraph is fiction... 82.72.139.164 (talk) 09:32, 14 May 2018 (UTC)
thread_title:  Calculation in History seems completely wrong?