LM3886 Schematics + PCB

[batteryman]

Originally Posted by charlestpt

Is the circuit used in this PCB is same as in the Datasheet of LM3886? if not there would be any loss of quality of sound,power,frequency range etc

can i use this speakers for home on this amplifier
JBL GT6-S266

The pcb layout is not critical for audio circuits so there won't be any loss of quality if the schematic is not the same as the datasheet.

You might consider using two LM4780 dual chipamps which can be run with the amps paralleled for more current for 4ohm speakers.

Car speakers are designed for use in a small volume and will not be very good for home use unless your listening room is very small. You will also have to design a cabinet for them using the Thiele Small parameters which are not shown.
In a vehicle, you are actually sitting inside the louspeaker cabinet and it is the pressure changes that transmit much of the sound. (which is why you feel the bass in a car more than you do in your listening room).

[RogerGustavsson]

Originally Posted by charlestpt

Is the circuit used in this PCB is same as in the Datasheet of LM3886? if not there would be any loss of quality of sound,power,frequency range etc

can i use this speakers for home on this amplifier
JBL GT6-S266

Have you heard these speakers with an enclosure in your home? As they are intended for car applications, I think you will be disapointed of the sound in your home. In the car bass is boosted and higher frequencies absorb. At home I suspect them to sound thin and forward. I guess the speakers drop to about 3 ohm, a heavy load for a single LM3886. If you want really balanced sound in your home there are better suited speakers.

[charlestpt]

Originally Posted by batteryman

The pcb layout is not critical for audio circuits so there won't be any loss of quality if the schematic is not the same as the datasheet.

You might consider using two LM4780 dual chipamps which can be run with the amps paralleled for more current for 4ohm speakers.

Car speakers are designed for use in a small volume and will not be very good for home use unless your listening room is very small. You will also have to design a cabinet for them using the Thiele Small parameters which are not shown.
In a vehicle, you are actually sitting inside the louspeaker cabinet and it is the pressure changes that transmit much of the sound. (which is why you feel the bass in a car more than you do in your listening room).

Originally Posted by RogerGustavsson

Have you heard these speakers with an enclosure in your home? As they are intended for car applications, I think you will be disapointed of the sound in your home. In the car bass is boosted and higher frequencies absorb. At home I suspect them to sound thin and forward. I guess the speakers drop to about 3 ohm, a heavy load for a single LM3886. If you want really balanced sound in your home there are better suited speakers.

I want to use those for satellite speakers in 2.1 system
as you all telling me that these are not suitable for home listening but here in my place there are no Hi-Fi full range speakers are not available thats why i have chosen them if you have any idea about Hi-Fi speakers in India please suggest me,here only i can have woofers

[RogerGustavsson]

I have no idea of what kind of speakers you have in India. A poweramp based on LM3886 can justify even very good speakers. Unfortunately, low impedance speakers (as car speakers) are not the best match. Three LM3886 in parallel for each channel can do it but it will also call for a bigger poeer supply. A pity, you do not have access to real hifi speakers for home use. What kind of enclosure do you have in mind for the JBL-set?

[gootee]

Originally Posted by batteryman

The pcb layout is not critical for audio circuits so there won't be any loss of quality if the schematic is not the same as the datasheet.

<snipped>

batteryman,

Whiskey Tango Foxtrot?!

The PCB layout most certainly IS critical, for audio circuits.

And if a schematic is changed, there COULD be a change in sound quality.

The two are independent of each other so your statement makes no sense as a conditional. And the two parts of it are both completely wrong, anyway, as general statements.

I haven't read the rest of the thread so I hope that your intended advice was correct, in this case, even though the way it was said can't stand on its own.

Tom

[batteryman]

Originally Posted by gootee

batteryman,

Whiskey Tango Foxtrot?!

The PCB layout most certainly IS critical, for audio circuits.

And if a schematic is changed, there COULD be a change in sound quality.


Tom

.
But I never said 'Schematic' you did and this means changing the circuit.

I said 'PCB layout' - this means altering the track routing NOT the schematic.

Small changes in the pcb design are not audible.
BM

[udailey]

Originally Posted by gootee

batteryman,

Whiskey Tango Foxtrot

Tom

OMG LMAO ROFL!!
A great way to start my day. Thank you Tom

Uriah

[udailey]

Alter a great grounding scheme, run a signal trace along an AC power input track, place a cap an inch away from the power input leg of an opamp rather than right up against it...all these will be audible changes.

[AndrewT]

Whisky Tango Foxtrot. Scottish, Argentinian & USA combined.
Nice to have some Internationalists with us.

I agree totally: PCB and/or circuit layout do affect the audible sound !!!!

[benb]

Originally Posted by RogerGustavsson

I have no idea of what kind of speakers you have in India. A poweramp based on LM3886 can justify even very good speakers. Unfortunately, low impedance speakers (as car speakers) are not the best match. Three LM3886 in parallel for each channel can do it but it will also call for a bigger poeer supply. A pity, you do not have access to real hifi speakers for home use. What kind of enclosure do you have in mind for the JBL-set?

To run them in parallel you need well-matched gain-setting resistors as well as a resistor on each chipamp output. It bothers me to see this tossed out without urging readers to carefully and thoroughly read the datasheet and applicable app notes, otherwise you might as well toss these things into a fire.

Originally Posted by batteryman

.
But I never said 'Schematic' you did and this means changing the circuit.

I said 'PCB layout' - this means altering the track routing NOT the schematic.

Small changes in the pcb design are not audible.
BM

It depends on where it is - often some areas "aren't so important," but with the LM3886 (or really anything in the "chip amps" forum) most all areas ARE important. There's the full output and power currents going right next to a line-level signal. If the speaker ground current shares a trace with the line-level ground (a "logical" thing for a less-than-fully knowledgeable layout person to do) then it's a bad layout. Read the LM3886 data sheet and related app notes. Read every square inch (or square centimeter/centimetre) of them.