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Old 2nd December 2012, 01:02 PM   #11
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One of the plots in the datasheet shows Mute attenuation vs Mute pin voltage. Those conditions show <~1.4V as full mute disable. Best to stay out of gray undefined logic areas and attempt to get as close to 0V and 5V as practically feasible.
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Old 5th December 2012, 07:47 AM   #12
pra3718 is offline pra3718  India
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Default Still there is hope

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I kept circuit as it is for half an hour. And power on again. This time amp was mute and could not play. Power switch OFF and ON immediately, Amp started playing after 2-3 Seconds. I could not understand, why amp could not played first time ?
There is no problem in mute circuit... Overall something is wrong with my Amp or power supply. I disconnected mute and played as it was basic build. I found, 1st time it does not played. Switch off and immediately switch on and played. Just playing half an hour, then switch OFF and immediately switch on not played again..

It is working like toggle switch NOT PLAYED = SWITCH OFF- AND SWITCH ON = PLAYED..

why ? I found, SWITCH-ON = NOT PLAYED. condition .... I measure the voltage at power supply. 22(+/-)VDC correctly supplied to Power-amp but Regulator 7818 is not supplying +18VDC DMM shows below <1 vdc WHY ? I could not understand.

Again SWITCH-OFF AND SWITCH-ON condition Amp stared playing and Regulator 7818 correctly shows +18VDC by DMM.

I have fitted 7805 regulator for muting. 7818,7918 for crossover.
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Old 5th December 2012, 11:00 AM   #13
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Schematic?
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Old 8th December 2012, 06:21 AM   #14
pra3718 is offline pra3718  India
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Quote:
Schematic?
@bobodioulasso, sorry for late. Infact I did not have schematic and I build it. Mean time I found when I connect my mp3 player DAC then only it behave like this (post # 12)

I suspect my power supply Please comment..
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Old 8th December 2012, 06:24 AM   #15
pra3718 is offline pra3718  India
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Opps. This is schematic
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Old 8th December 2012, 01:31 PM   #16
pra3718 is offline pra3718  India
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@AndrewT, Please help to complete LM1876 project. Mostly I have build as per your advices. I am stuck-up at Post # 12. If it is not correct thread to ask so pls advice that.

Best Regards.
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Old 8th December 2012, 01:33 PM   #17
AndrewT is offline AndrewT  Scotland
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No.
I give up because you ignore virtually any advice I gve.
I will not waste any more time on you.
But if you post balderdash for others to read I will refute your rubbish.
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Old 8th December 2012, 02:10 PM   #18
pra3718 is offline pra3718  India
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I could not understand, what hearts you exactly. I always accept your recipe. SORRY
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Old 8th December 2012, 07:19 PM   #19
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Quote:
Originally Posted by pra3718 View Post
Opps. This is schematic
I think you cannot power up simultaneously the crossover and the amp
A crossover produces a big thump at powering on and off, so it's preferable to power both on and off in the right sequence.
I am not shure you can manage this using mute only.

Mute pin needs series resistor to limit current.
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Old 9th December 2012, 09:51 AM   #20
pra3718 is offline pra3718  India
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My primary concentration is the problem post # 12.

Quote:
A crossover produces a big thump at powering on and off
There is sound at powering ON and absolutely quit at powering OFF.
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