Talk:Line level

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We should clarify that it's not necessarily a difference in level, but a difference in impedances and the amount of power that can be sourced by an output. Line level outputs are not meant to drive loads like headphones. — Omegatron 22:43, 21 November 2006 (UTC)[reply]

Section: Overview

The end of the Overview section currently states that the line level output strength on a device is not affected by the source volume setting. Does this need clarification/removal? Almost all of my pro audio equipment which uses line level outputs has a master volume knob which affects the sound leaving the line level output. Does it just refer to the general line strength or something? Lexusperplexus (talk) 14:34, 16 March 2011 (UTC)[reply]

Units

I just finished changing all the units in the article. I had looked here in the talk page beforehand, but neglected to flip through the history, which revealed a number of other editors having changed the units in various ways.

To explain my changes, I tried to make the words uniform (i.e. if it says 1 kX for one thing, it shouldn't say 1000 X for another), and beyond that, merely be as faithful as possible to the house style for units (spell out the word of a unit once, use its correct abbreviation thereafter, use a non-breaking space before the unit, uniform significant digits, etc). The WP guidelines are fairly scattered through the help, but a few of the changes are clumped nearby in WP: 'unit' style (and its surrounding sections and pages).

I think having this article's numbers and units clear, correctly wikilinked, and uniform in style is very important to the article's integrity. If there are objections to anything I've done, let's please discuss it! —Joel D. Reid 06:17, 30 May 2007 (UTC)[reply]

Sentence adjustment

This sentence: "signals are then typically sent to a device known as a power amplifier, where they are amplified to levels that can drive headphones or loudspeakers, which convert the signals back into sounds that can be heard through the air."

In my opinion, the section "which convert the signals back..." should just be dropped. It's unnecessary and confusing.

Sources for common nominal levels

This bit: "The most common nominal level for consumer audio equipment is −10 dBV, and the most common nominal level for professional equipment is 4 dBu. By convention, nominal levels are always written with an explicit sign symbol. Thus 4 dBu is written as +4 dBu."

Does anyone have a source for this? —Preceding unsigned comment added by 198.137.214.36 (talk) 18:05, 11 June 2009 (UTC)[reply]

manualshark.org's PDF

I removed both references to manualshark.org's PDF file (used to 'source' the colors used for line in and line out).

The whole PDF is wholly black and white and doesn't make any mention of colors except for microphone in being 'blue' --not light blue mind you-- which still contradicts PC_System_Design_Guide#Color-coding_scheme_for_connectors_and_ports (mic in is not a line in). Olivier Diotte (talk) 06:43, 1 February 2011 (UTC)[reply]

See for yourself: http://www.manualshark.org/manualshark/files/28/pdf_27618.pdf Olivier Diotte (talk) 06:45, 1 February 2011 (UTC)[reply]

Contradiction: Line In/Line Out Impedance

The article indicates that the impedances of Line In and Line Out should be the same. However it states that one is 100 ohms while the other is 10 Kohms.CountMacula (talk) 10:20, 22 September 2012 (UTC)[reply]

The article goes into some detail about how line level connections use what is called a "bridging" connection, in which the output (source) impedance is considerably lower than the input (load) impedance. I can't see where the article indicates or even implies that they should be the same. Can you be more specific as to where this is? We should certainly fix it if it's there... but I think you're misinterpreting. Jeh (talk) 10:56, 22 September 2012 (UTC)[reply]

I guess it's possible that I am misinterpreting. I will give a pointer about how you could decide. Most browsers have a feature to search the page being displayed. It may be under an "edit" feature in the file menu or similar. Try that and you will get a search box where you can type in the word you are looking for, such as "impedance", or even a number, such as "100" or "10". Doing that would lead you to the text fragments:

"Line in expects the kind of voltage level and impedance that line out provides."

"A line input has a high impedance of around 10 kΩ"

"The [line out] impedance is around 100 Ω"

CountMacula (talk) 05:46, 29 September 2012 (UTC)[reply]

I am well aware of my browser's "text search within page" feature. And I am well aware of that particular part of the article, as I contributed to it.

There is no contradiction; every statement there is true. Line in presents an impedance of 10 kOhms, but is designed to be driven by a source of much lower impedance. The source driving impedance and the load impedance do not have to be the same; this would in fact break the rules of a "bridging connection". This is further described in the text immediately following the "Impedances" heading, and in even more detail in the "impedance bridging" article linked from there. Jeh (talk) 07:53, 29 September 2012 (UTC)[reply]

Thank you for that explanation. It seems that you can tolerate a little leg pulling. But now may I ask you to to change something about the article to eliminate what hung me up? I don't think it is practical to leave it as it is, that is if the purpose is to efficiently impart understanding to someone such as me who does not already understand.CountMacula (talk) 09:53, 29 September 2012 (UTC)[reply]

voltage on differential lines.

The article mentions that pro lines are usually differential and then it says that the level is x dbu... OK. So are you measuring each phase with respect to ground or a load placed between the two phases? I tried to find this information elsewhere but I haven't yet succeeded. — Preceding unsigned comment added by 108.28.74.221 (talk) 16:01, 20 March 2013 (UTC)[reply]

Nominal Levels: Approximate?

If 1.736 volts is "approximate", why is it given as four significant figures, down to millivolt precision? 24.85.131.247 (talk) 05:35, 3 August 2013 (UTC)[reply]