I have got LM3886 but its not getting unmute.
Please suggest Rm value for power supply of 18-0-18 dc.
When i disconnected Rm and left the pins untouched, there was only a little sound and that too even in max. input signal (full volume), indicating it to be in a mute condition.
I have seen datasheet and tried 22k, 10k, 5k,and 1.5k, but its still mute.
The rest schematics are according to figure1 of datasheet
CHANGES: replaced 22u with 47u and omitted Cm.
Please reply soon!
Please suggest Rm value for power supply of 18-0-18 dc.
When i disconnected Rm and left the pins untouched, there was only a little sound and that too even in max. input signal (full volume), indicating it to be in a mute condition.
I have seen datasheet and tried 22k, 10k, 5k,and 1.5k, but its still mute.
The rest schematics are according to figure1 of datasheet
CHANGES: replaced 22u with 47u and omitted Cm.
Please reply soon!
I have got LM3886 but its not getting unmute.
Please suggest Rm value for power supply of 18-0-18 dc.
When i disconnected Rm and left the pins untouched, there was only a little sound and that too even in max. input signal (full volume), indicating it to be in a mute condition.
I have seen datasheet and tried 22k, 10k, 5k,and 1.5k, but its still mute.
The rest schematics are according to figure1 of datasheet
CHANGES: replaced 22u with 47u and omitted Cm.
I would try with Rm 18k connected to V-. It should pass current over 0.5 mA for mute off, according to datasheet.
guys please help. I moved halfway across India to purchase two expensive lm3886 and now its not getting mute off. I placed ammeter in series to pin8, at Rm=5k, it showed 0.99 mA and at 1.5k it showed 1.42mA. But its not working either way. Accidently, I was holding sink with my hand and touched pin8, I heard a little DB gain in comparison to little sound at mute(pin 8 left opened n untouched) I have spend so much time and money that I m literally crying now Please help me!
guys please help. I moved halfway across India to purchase two expensive lm3886 and now its not getting mute off. I placed ammeter in series to pin8, at Rm=5k, it showed 0.99 mA and at 1.5k it showed 1.42mA. But its not working either way. Accidently, I was holding sink with my hand and touched pin8, I heard a little DB gain in comparison to little sound at mute(pin 8 left opened n untouched) I have spend so much time and money that I m literally crying now Please help me!
I have no experience with LM3886 but looks like Rm current is too small for +-18V and 5k value. Check GND (pin 7) as well as power supply pins.
I have no experience with LM3886 but looks like Rm current is too small for +-18V and 5k value. Check GND (pin 7) as well as power supply pins.
i have made more complex amps using tda7386, tda7294 perfectly working in once
and am not sure i am doing this ic correct. HOW FUNNY is that!
Moreover as i mentioned, i checked the current using multimeter in series from Rm to -V. At 5K it showed 0.99mA, but still no sound. At 1.5k, 1.4mA current was read, still the same.
Little worried if these are fake/damaged. But both ics showing same behaviour, i.e., at pin8 open, a little sound at full signal input whereas as soon its connected to -V via. 1.5K/5K/10K/22K, the little sound stops coming.
Here is the exact schematics I built.
Attachments
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Does the non-inverting input have a dc-ground referance connection somehow? Schematic shows a single ground symbol which can't be right. There should be a separate ground path for: 1) input, feedback and pin 7 as a group, 2) power supply decoupling, and 3) speaker return and zobel. The power supply decoupling should be one small value ceramic disk (preferably COG/NPO) around 100nF with leads short as possible connected as close as possible to each supply pin and short path to common ground connection, and a medium size electrolytic (470uF to 1500uF) connected similarly with shortest possible leads.
Mike
Mike
Does the non-inverting input have a dc-ground referance connection somehow? Schematic shows a single ground symbol which can't be right. There should be a separate ground path for: 1) input, feedback and pin 7 as a group, 2) power supply decoupling, and 3) speaker return and zobel. The power supply decoupling should be one small value ceramic disk (preferably COG/NPO) around 100nF with leads short as possible connected as close as possible to each supply pin and short path to common ground connection, and a medium size electrolytic (470uF to 1500uF) connected similarly with shortest possible leads.
Mike
Oops, I had drawn so by mistake. Here is what i meant.
BTW, every diode is parallelly attached to 100nf. And i am quite sure this does not have any relation to the problem i am facing.
If i am missing something very important here, please at least draw me a rough sketch of modifications u recommend.
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Hi,
One thing that I noticed is that you are running both Lm3886 to the minimum permissible voltage allowed. I am running my at +/- 40 volts. I am not saying that running at +/- volts will not worked but it is a thought.
I didn't get your point. please be specific.
You need a resistor from pin 10 (Vin+) to ground
are you sure that its responsible for no sound, because I m feeding input via. 100k analog controller
are you sure that its responsible for no sound, because I m feeding input via. 100k analog controller
Maybe your input is attenuated, try with resistor to gnd and another source.
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