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Subject: my Archos frequency analysis & power consumption test results
From: Uwe Freese (mail_at_uwe-freese.de)
Date: 2002-07-27


Hello,

I tested frequency range and power consumption of my archos. Even if
it's not rockbox-specific, I think some of you could find this
interesting. If such mails are not welcome here, please let me know.

BTW: I'll give the haxx.se webmasters some detailed gifs, maybe you'll
find them there in the next days.

Here are the results:

------------
Measuring some archos parameters,

Used model: Archos Recorder 20, Archos-Firmware 1.28

*** Playback Frequency Ranges

Waveform created with CoolEdit, 0-24kHz Sine-sweep, 48kHz Samplingfreq., 240s running time,
saved with Fraunhofer FaastEnc-Codec to Mono-128 kbps MP3 (48 kHz, 24kHz cutoff),
playback on archos recorder 20,
recorded with Soundblaster 1024 at Line-In (48 kHz)

Comment: The MP3 Codec and Soundcard used are very good and have a
good frequency response. I think the frequency range shown are limited by the archos.

Result: Frequency Range ~ 55 - 23.000 Hz (-6dB)

*** Recording Frequency Ranges

Waveform created with CoolEdit, 0-24kHz Sine-sweep, 48kHz Samplingfreq., 240s running time,
playback on Soundblaster 1024, Digi-Out / Line-Out,
recorded with archos, highest quality, 48 kHz Samplingfreq.

Result: Both digi and analog recording have good "frequency balance",
but frequency cutoff at 15.500 Hz! -> not rec'd for CD recording, but ok for analog tapes,...

*** Power consumption

values of a digital amperemeter between the accus

HDD off, LED off, idle 94 mA
HDD off, LED off, play 97 mA
HDD off, LED on, idle 129 mA
HDD off, LED on, play 131 mA
HDD on, LED on, play 230 mA
HD on, reading, LED off ~ 600 mA
HD spin up before read max 800 mA

HDD is 11% on with Archos firmware and playback of 256kbit/s file.

Bye, Uwe.



Page was last modified "Jan 10 2012" The Rockbox Crew
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