pcb board only hifi jeff rowland two parallel btl mold lm3886 2 parallel Jeff Rowland mono amplifier board lm3886 amplifier-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group
please see the link above ,(no instructions as usual) this has probably been debated many times , but could some one clarify on how to set up the bias + dc offset ect on this board? you have 2 test points v1 and v2 , i am presuming you connect the speaker outputs to a 8ohm resistor and using a multi meter on volt setting connect the (-) of multimeter to (ground or power -)???? and the (+) multimeter probe on v1 and reduce the voltage to as close to 0 volts as possible , and then the same to v2 and ultimately match the voltage between v1 and v2 to the lowest voltage ???? if you can confirm thanks
please see the link above ,(no instructions as usual) this has probably been debated many times , but could some one clarify on how to set up the bias + dc offset ect on this board? you have 2 test points v1 and v2 , i am presuming you connect the speaker outputs to a 8ohm resistor and using a multi meter on volt setting connect the (-) of multimeter to (ground or power -)???? and the (+) multimeter probe on v1 and reduce the voltage to as close to 0 volts as possible , and then the same to v2 and ultimately match the voltage between v1 and v2 to the lowest voltage ???? if you can confirm thanks
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There is no 'bias' setting to be done, R7 & R8 help to avoid a DC offset. The two pots only decrease the resistance from the +ve non inverting input to ground and according to the manufacturer, Texas Instruments, they have no appreciable affect. If the potentiometers wiper was connected to the +ve input and one end went to a positive potential and the other end to a negative potential, it would allow DC trimming of the outputs on pin 3.
Not a good idea in my opinion.
Not a good idea in my opinion.
Most of the parallel chip amp circuits I've seen are not a good idea.
TI has a tutorial on paralleling and bridging the 3886. It addresses the actual, real world issues and is a good starting point.
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