Rockbox Technical Forums

Third Party => Repairing and Upgrading Rockbox Capable Players => Topic started by: Moogle on August 20, 2019, 09:54:23 AM

Title: Sansa Fuze V1 Line Outpt
Post by: Moogle on August 20, 2019, 09:54:23 AM
This is just an idle question, asking out of interest. My Fuze V1 came with a little cable, with a data connector at 1 end and a 3.5mm stereo jack plug on the other.

With the original SanDisk firmware booted, this cable provides what seems to be a line level output. During playback, varying the volume level has no effect on the output level from the plug, which stays constant.

I had assumed that Sansa must have provided a hard wired output which bypassed the volume control function, but when trying it with Rockbox booted I find that varying the volume does vary the output level from the jack plugl.

Can anyone explain why the difference?
Title: Re: Sansa Fuze V1 Line Outpt
Post by: saratoga on August 20, 2019, 12:51:09 PM
Line out used to be constant, didn't realize it wasn't anymore, but I can guess why.  Internally there are two volume control units in series that are used for lien out, one for the line out amplifier and one that is global.  The line out one is locked at maximum, but the global one is used to for headphone volume control.

If you use line out and then adjust volume, does the line out volume only change for lower volume settings and then hit maximum (probably around -20dB or so) and stay constant as you increase volume?
Title: Re: Sansa Fuze V1 Line Outpt
Post by: Moogle on August 20, 2019, 03:28:01 PM
Thanks Saratoga. Yes, I'm surprised I hadn't noticed that. The volume climbs to a max at - 35db, then stays constant above that.