Support and General Use > Hardware
Sansа Clip Zip - Improve battery life
Mihail Zenkov:
Output stage based on op-amps. For change gain we should change negative feedback. If we rise supply voltage we don't have gain change. If we set voltage lower than op-amp have need, we have limit volume with huge distortion.
Another variant - get louder signal from DAC, but IMHO we get all possible from it (+6dB).
saratoga:
--- Quote from: Mihail Zenkov on December 28, 2014, 05:04:47 PM ---Output stage based on op-amps. For change gain we should change negative feedback. If we rise supply voltage we don't have gain change. If we set voltage lower than op-amp have need, we have limit volume with huge distortion.
--- End quote ---
Thats true for a class AB amp, but do the class D amps in these devices work like that? My understanding is that the gain is proportional to the supply voltage (since they're really just switching the supply on and off).
--- Quote from: Mihail Zenkov on December 28, 2014, 05:04:47 PM ---Another variant - get louder signal from DAC, but IMHO we get all possible from it (+6dB).
--- End quote ---
You can do this by increasing the gain in the mixer stage, but it simply distorts due to the limited rail voltage on the headphone amplifier.
Mihail Zenkov:
--- Quote from: saratoga on December 28, 2014, 05:44:33 PM ---Thats true for a class AB amp, but do the class D amps in these devices work like that?
--- End quote ---
Are you sure about D class in this player?
I not familiar with class D but in this case we shouldn't have DAC and LDO. Also I not sure is phantom ground possibly on class D.
--- Quote ---You can do this by increasing the gain in the mixer stage, but it simply distorts due to the limited rail voltage on the headphone amplifier.
--- End quote ---
I test this mode before and it have some problem but not sure about clipping. In any case this not have real sense as mixer worse audio quality.
404_user_not_found:
--- Quote from: Mihail Zenkov on December 28, 2014, 11:30:55 AM ---Can you try rise CVDD1 to 20 (in patch it 19), set CVDD2 to 112 and check battery runtime again?
--- End quote ---
Crashed after some hours of runtime test.
Mihail Zenkov:
404_user_not_found:
Ok. Thanks!
saratoga:
Can you provide new test build for clip+ users with CVDD1=20 and CVDD2=113 ?
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