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Chip Amps Amplifiers based on integrated circuits

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Old 21st September 2018, 09:00 PM   #1
rookiesparks is offline rookiesparks
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Connect up to 4x LM3886 ICs in Parallel Chipamp Gainclone PCB only DIY | eBay


Connect up to 4x LM3886 ICs in Parallel Chipamp Gainclone PCB only DIY | eBay

hi can some one give me advice on the above link for a 4 x lm3886 in parallel,is it any good ? any recomendations ? all gratfully received thanks
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Old 21st September 2018, 09:14 PM   #2
OlegSh is offline OlegSh
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It looks like all LM3886 ICs lack decoupling capacitors.
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Old 21st September 2018, 09:24 PM   #3
rookiesparks is offline rookiesparks
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Is that something I can alter on the PCB ???
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Old 21st September 2018, 09:30 PM   #4
OlegSh is offline OlegSh
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if there is power GND near the power pins then probably yes.
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Old 21st September 2018, 09:39 PM   #5
rookiesparks is offline rookiesparks
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V+ grand v- 3pins close any suggestions as I'm new at this
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Old 21st September 2018, 09:52 PM   #6
OlegSh is offline OlegSh
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The GND should be available near the power pins of all LM3886 ICs. Then you can add local decoupling capacitors for all of them.

Next are the compensation networks around all LM3886 (look at the datasheet schematic). The parts forming compensation networks are not optional even if datasheet says otherwise. All these seems missing on the PCB that you selected.

In any case, before looking at the ebay offerings, read Tom Christiansen's "Taming the LM3886 Chip Amplifier" article. It will help you understand what to look for on all those LM3886 PCBs.
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Old 22nd September 2018, 02:05 AM   #7
adason is offline adason  United States
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Originally Posted by rookiesparks View Post
Connect up to 4x LM3886 ICs in Parallel Chipamp Gainclone PCB only DIY | eBay


Connect up to 4x LM3886 ICs in Parallel Chipamp Gainclone PCB only DIY | eBay

hi can some one give me advice on the above link for a 4 x lm3886 in parallel,is it any good ? any recomendations ? all gratfully received thanks
Why do you need four in parallel?
One makes 68 watts. Do you know how loud is that with reasonably sensitive speakers? Do you know how much power is needed for normal listening? No more then one watt!
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Old 22nd September 2018, 08:05 AM   #8
rookiesparks is offline rookiesparks
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Default 4 lm3886

hi thanks for you reply, the question of power on 4 x lm3886 ! i have made a single lm3886 set up and the volume level is adequite and a nice sound quality, then i bridged 2 idividual units ,and yes there is more volume but what i personaly noticed was the bass had more authority and basicaly a different animal alltogether much more detail !! my quest is how much better can it get ?so ime on here for help and guidence from you the gods of hifi, so any info is appreciated........ if the ebay pcb are not ideal is there any alternatives out there i can buy , iv tried to contact chipamp.com but seems the site is closed down !!
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Old 22nd September 2018, 09:34 AM   #9
adason is offline adason  United States
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In that case try lm3886 in transconductance configuration. See Joe Rasmussen threads and web.
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Old 23rd September 2018, 11:32 AM   #10
rookiesparks is offline rookiesparks
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Default bpa 300 help

hi iv done more research on parallel lm3886 projects and found threads on this pcb see( attachment ) is that a better pcb than the last one ??the problem being new to this, is trimming the dc offset on on each lm3886 ,,, ???? i cant find any info on doing this ,, i am presuming by using a multimeter set to milli volts and one probe on a point on the pcb and same with the other and adjust as close to zero as possible my question is,,,,,, what procedure ? what two points to take the measurment ? thanks
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