line-level output for Sansa e200

[PickupBetty]

It will probably never happen, since it's already been visited elsewhere in the forum, but I'll go ahead and mention it here.

The only exception I can find to Rockbox's complete superiority over the Sansa e200 original firmware is the lack of line-level output from the dock connector.  I'd love to be able to use my e200 with my boombox, but I'm afraid I'll blow my e200's amp by constantly cranking it up near max.

It's strange: my iPod Photo's Rockbox has line-level output for the dock connector, just not my Sansa.

But even without the line-level output, Rockbox for Sansa is fabulous.  Thanks, developers!

[saratoga]

I don't think anyone has looked into locking the line out volume at max automatically, but its pretty easy to change manually when you're using line out (just be sure to lower it again before using headphones).

[PickupBetty]

How does one do that?

First, let me make sure I'm not way off; I am merely a casual user.  As I understand, line-level is the original output level of a DAP.  When the output hits the headphone jack, it is impeded -- meaning it hits some sort of resistor so it's not as loud.

So when I try to use my Sansa (via the headphone jack) as a line-in to my boombox, I have a subdued signal that I then have to crank back up to a loud signal via volume control.

But you are saying that I can lock the line out (of my dock connector) to max somehow -- this is different from just setting my headphone volume to max.  Then I can use the dock connector to connect to the boombox, but not have to alter my volume control.  And save my amp.

Am I close?  Thanks for your input.

[Llorean]

If you set the e200's volume to 0db it's outputting from the DAC at the same level as you'd call "line level." Then if you use the dock connector (which may or may not have different properties than the headphone jack physically) you'll be getting the same line-level as the original firmware.

[saratoga]

First, let me make sure I'm not way off; I am merely a casual user.  As I understand, line-level is the original output level of a DAP.  When the output hits the headphone jack, it is impeded -- meaning it hits some sort of resistor so it's not as loud.

Its actually the other way around.  The line out has the resistor, the headphone out has almost no resistance (ideally none at all).

But you are saying that I can lock the line out (of my dock connector) to max somehow -- this is different from just setting my headphone volume to max.  Then I can use the dock connector to connect to the boombox, but not have to alter my volume control.  And save my amp.

Am I close?  Thanks for your input.

I'm saying you could write code to automatically raise the volume, or else just raise it yourself.  0dB is line out.

[PickupBetty]

Thanks -- when you say code can be written to raise the volume, are you talking about the output from the pins/dock connector only, or just the whole volume setting for the entire Sansa?  I certainly don't understand the science, so I assumed that "impedance" was what diminished the headphone jack's output at lower volume levels.

This I do know: my iPod's dock connector has a loud (I assume line-level) output, regardless of the headphone's volume.  So when I use my iPod (dock connector) with my boombox, I can keep the volume set at -36dB, and it still plays fine. 

On the other hand, my Sansa's dock connector and the headphone jack have identical volumes however loud I set it.  To connect it to my boombox, I have to set it at 0+dB, whether I use the headphone jack or the dock connector.

What I would like to do is obviate the need to crank up the headphone volume unnecessarily, because I read somewhere that doing so can wear/blow out the amp.  My understanding is that line-level output from the dock connector (like I have in my iPod Rockbox) would take care of that.

I'm not a developer or any type of programmer, but if someone knows of a way I can alter my source code to achieve this, I'd be happy to try.  I just thought I'd post this suggestion in case one of the developers wanted to take a stab at it.

[torne]

Setting it to 0dB means you are running the amplifier in the player at its intended output level. This will not damage it.

[PickupBetty]

I'm not doubting you, but could you explain how it works to me?

Why does the line-level dock connector output on my iPod stay loud, regardless of the headphone output?  Is the amp working overtime if I crank the headphone volume up?  Is it not pushed at all if the headphone volume is down, but the dock connector stays loud?

My Sansa (on Rockbox) has a range of -74dB to +6dB.  At 0dB, it's almost at its max and way above comfortable headphone volume.  How can that not strain the amp?

Thanks for your patience.

[Llorean]

Notice that going down from 0db gets *lower* numbers. -1, -2, etc. The hardware inside the player is reducing the volume below 0db normally, not amplifying it up to it. 0db is "line level" the natural level.

On the iPod the line-out can be adjusted like the headphone out, but it's simply locked to 0db in the software. This is how it's supposed to work. There is no "magic" that allows a loud signal without anything to actually make it loud. It goes through the exact same amplification process as headphone output at 0db does, there's just different resistance on the line.

You aren't straining the amplifier in the player by adjusting the volume.

[PickupBetty]

Thanks, Llorean -- I sort of understand.  I'll do a bit more reading on my own, too.

But, I'd still love to see line-level output from the dock connector.....

[Llorean]

Set the volume to 0db. That is line level.

[yapper]

There was some discussion on line out (specifically on the Griffin PowerDock which can be used with the c200 and e200) here: http://forums.rockbox.org/index.php?topic=21390.0

[PickupBetty]

I revisit this thread periodically, in the hopes that someday there will be a magic post that dock output is now set at line level for the Sansa e200.  Given the number of views, I'd say others are interested, too.

Since it hasn't changed, I was wondering if there was anyone who could teach me how to set it myself?  Or help me write a patch to do so?

Just a thought.....

[[Saint]]

I was wondering if there was anyone who could teach me how to set it myself?

Simply set the volume on your DAP to 0db when you are using the dock connector, this is line level.



[St.]

[PickupBetty]

Actually, I meant setting it in the code.  I'd prefer not to crank up my volume -- it's a waste of battery and also a pain to remember when I want to use headphones again.  Literally a pain, when the music blasts out my eardrums.

I don't know anything about editing the source code myself, or else I'd try to figure it out.  In Linux, I have the option of changing configuration for this or that, and it's quite easy.  I thought that there's just one parameter that needs changing.  My ipod Rockbox has line level dock output.  There are plenty of reasons why dock output should be line level, and I can't think of any why it shouldn't.

I'm not asking for everyone to have it if it offends them, however.  I'm only asking if someone could help me change my own configuration.

Thanks