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LM3886 x 3 First Test

Posted 16th August 2011 at 05:29 AM by panson_hk

I briefly measured the LM3886 x 3 parallel board this morning. THD vs freq for one, two in parallel and three in parallel are measured.

Load of 4 Ohm was also tested. When using one 3886, the on-chip protection activates periodically when doing low frequency (~ < 500 Hz) test. No such protection operation happens for the same output level for higher frequencies (>1kHz). The problem goes away when using 3886s in parallel.

More systematic tests will follow.
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  1. Old Comment
    abraxalito's Avatar
    Plots look very interesting - but are you using the 22kHz AP filter? If so it would be even more interesting to see with the 80kHz filter used That way the distortion doesn't appear to go down from 10kHz and up.
    Posted 16th August 2011 at 08:20 AM by abraxalito abraxalito is offline
  2. Old Comment
    panson_hk's Avatar
    Yes, I used 22k filter. 30k and 80k will be used in coming tests. Thanks!
    Posted 19th August 2011 at 02:21 AM by panson_hk panson_hk is offline
  3. Old Comment
    abraxalito's Avatar
    I saw your post with the 80k filter on the 'Parallel 3886' thread - but the plots look too small on my screen. (My eyesight also is not so good ha). Would you be able to post up bigger plots? I'm curious to see the improvements!

    <edit> Maybe one idea is to expand the scale so the curves appear further apart - make the max displayed distortion 0.05% perhaps?
    Posted 20th August 2011 at 12:45 AM by abraxalito abraxalito is offline
    Updated 20th August 2011 at 12:47 AM by abraxalito

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