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FS#11364 - AS3543 volume increase
Attached to Project:
Rockbox
Opened by MichaelGiacomelli (saratoga) - Sunday, 06 June 2010, 20:32 GMT+2
Last edited by MichaelGiacomelli (saratoga) - Thursday, 24 June 2010, 03:15 GMT+2
Opened by MichaelGiacomelli (saratoga) - Sunday, 06 June 2010, 20:32 GMT+2
Last edited by MichaelGiacomelli (saratoga) - Thursday, 24 June 2010, 03:15 GMT+2
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DetailsVolume tests of RB, the OF, and different amp settings are here:
http://anythingbutipod.com/forum/showpost.php?p=471215&postcount=383 RMAA tests driving a load for the OF, RB and various settings are here: http://rmaa.elektrokrishna.com/index.php?dir=Comparisons/ Specifically, these two entries for the current SVN build and the patched one: http://rmaa.elektrokrishna.com/Comparisons/Clip%2B%20-%20Rockbox%20Volume%200x16%20-%20Official%20build%2016%20Ohm.htm http://rmaa.elektrokrishna.com/Comparisons/Clip%2B%20-%20Rockbox%20Volume%200x1B%20-%20Timar%20build%2016%20Ohm.htm ---- The AS chips use a two step volume control with separate levels for the DAC and headphone amp. This patch increases the DAC volume 7dB. So basically, +6dB in the current build (which does not distort) becomes 0dB in the patch (which also does not distort). The new +6dB corresponds to actually over driving the amp, and does distort (but probably not enough to notice in real music verses a full scale test tone). Interestingly the OF can drive as loud as our new +6dB with very little distortion, which might suggest we don't have one of the voltages set right somewhere. If we ever get a JTAGed as3525v2 player it would be great to dump the AS3543 registers. |
This task depends upon
Closed by MichaelGiacomelli (saratoga)
Thursday, 24 June 2010, 03:15 GMT+2
Reason for closing: Accepted
Additional comments about closing: Committed as r27101.
Thursday, 24 June 2010, 03:15 GMT+2
Reason for closing: Accepted
Additional comments about closing: Committed as r27101.
Perhaps the difference in volume comes from using microphone/FM/PCM muxing?
I only have my sound card line in to make recordings, is it enough to compare clip+ with clipv2 and fuzev2 ?
That said, even with this patch, the THD is still nearly 0 at 0dB, and surprisingly low even at +6dB, so I don't see figuring out exactly what the OF does as all that important.
Attached files are RMAA data. RB's IMD at low frequency is not as good as OF, but it seems, 0x1b with +6db have steel good performance.
Measured volume level is,
OF : 0.546V
RB with 0x1b : 0.310V
Thank you for this great work.
FS#11364- AS3543 volume increase + FS#11297_as3525v2-cpufreq-v10.diff).All test was with Maximum volume (RB with +6).
It seems something wrong with my test. I'll test again with clean RB with this patch only.
Both clean RB and patched RB have 0.310V of max volume (at +6). The result comes different with your test results.
Is this patch need to sync?
http://www.anythingbutipod.com/forum/showpost.php?p=470918&postcount=353
I used value 0x1b and kept Saratoga's "if CONFIG_CPU == AS3525v2" condition, but thought I'd stick this around just the mix_(l|r) values.
These are the results I got by playing a normalised white noise file on the Clip+ at maximum volume/ +6db, recorded using an M-Audio Audiophile 2496, from Cooledit Pro's "statistics".
Peak Average
Amplitude RMS
Original WAV 0 -9.42
Original Firmware -5.6 -16.71
Trunk (r26873) -10.36 -21.515
All 0x1b * -11.64 -22.89
mix_lr 0x1b ** -4.415 -15.395
* vol1.patch
** volume-only_mix_lr-r26873.patch
RMAA tests can be found below. I tried to include results for the trunk build, but I gave up as RightMark seemed to be having problems with the output.
http://peskett.co.uk/Clip_Volume_RMAA/ClipVol.html
Since you're actually increasing the volume range 6dB, you need to change rockbox to go from a volume of -72.5 - +6dB to -88dB - +6dB, otherwise you'll get that weird jump in volume.
OF : 0.546V (MAX)
RB with nickp's patch : 0.66V at +6, 0.369 at 0
And I checked clipping problem with DSSF3's software oscillator.
OF shows clipping at 0.546V. But at 0.324V, OF doesn't clipped. More than 0.324V, OF shows clipping.
RB doesn't clipped still 0.369V (0).More than 0.369V, RB shows clipping.
With nickp's patch we can have more volume with no clipping(0.369V) than OF(0.324V).
But nickp's patch gives same vol at 0 and 1 (0.369V). Maybe this problem should be corrected.
My headphones aren't very sensitive, so had never ventured down that low.
Yes, the patch I uploaded is entirely derived from the postings on the ABI thread (mainly timar, dfkt, funman & saratoga), but mainly I found snippets of code rather than a patch, so thought I'd post something here for people looking for a simple volume boost patch (seemed a better place). I seem to have added to the confusion though!
Edit: this will also break on the AMSv1 players, but its a start.
Loudest results so far using the white noise clip I tested earlier;
Peak Amplitude: -4.06 dB (OF: -5.6dB)
Average RMS: -14.85 dB (OF: -16.71dB)
No noticeable degradation in the RMAA tests (newest patch is Vol V2);
http://peskett.co.uk/Clip_Volume_RMAA/ClipVol2.html
Pressing "down volume" button ~1 sec, from 6db to -72db;
http://peskett.co.uk/Clip_Volume_RMAA/volume-curve.png
Now the volume level goes up to 0.69V(+6, clipping occured) and 0.369V(0,+1, clipping not occured)
But still volume level is not continuously down or up.
I found there are same volume section like, 0/1, -2/-3, -5/-6, -8/-9, -11/-12, -14/-15,,,,,, .
I checked this with DSSF3's software oscillator. You can easily check with that program or other similar programs.
FWIW I think this could also be used to increase volume on AMSv1 targets, but I haven't tried. Are they any louder in the OF then in Rockbox?
- audiohw_settings
- sound_val2phys?