An open source layout for LM3886?

Question on the Protection board's D5 (TVS diode) - schematic indicates its bi-directional and I am stuck between these two (4A and 11.1A TVS) TVS Diode P6KE110CA Littlefuse and TVS Diode 1.3KE100CA Littlefuse both at Mouser. Hoping someone could confirm if one is a better option, or are they both adequate for this position on the board.

I am a bit late here but I think based on 0940’s prior posts the TVS should have a working voltage slightly above supply rail voltage. For my setup that is around 40V. The part mentioned above seems to have a working voltage that is far too high at 94V. I use a P6KE47CA (40.2V). I believe the purpose of this TVS is to protect the MOSFETs from voltage spikes.

Gregg
 
Hey thanks,

This list might be of use to someone.

NameDesignatorFootprintQuantityManufacturer Part
bipolar 10ufC1E2,5-71UVP1H100MED
1N4148D1,D2,D3,D4DO41-7.641N4148-DIO
TVS DiodesD5P2-151P6KE200A
LED5MMLED1LED5MM1Fault indication LED
BC546BQ1,Q3TO92-EBC2BC546B
BC556AQ2,Q4,Q5TO92-EBC3BC556A
IRFB3607Q6,Q7TO220BV2IRFB3607
100kR1,R56,3-2,3 mm2
22kR26,3-2,3 mm1
22kR3,R46,3-2,3 mm2
220kR6,R86,3-2,3 mm2
8k1R76,3-2,3 mm1
3kR96,3-2,3 mm1
TLP3906U$1SO-61alternative APV1121S
22-27-2021-02J46410-021molex connector
D5, the TVS diode, needs to be bi-directional so the part number should end in CA. I believe the voltage for the part you have specified is too high at 171V. You want something with a working voltage slightly above the rail voltage. I am using a P6KE47CA (40.2V).
 
Hello folks. I have finished the Amp recently, but I have a bit of a trouble finding the right input Pot.

I have tried 10k and 100k log pots, but with both the volume gain wasn´t very linear. In fact I am getting about 95 percent of volume gain in first 1/4 of rotation of the pot. And the rest, so about 3/4 quarter of rotation brings almost zero Volume gain.

Am I using the wrong pot? so should I use linear instead of logarithmic? Or am I using wrong resistance?

Thanks,

Adam
 
You connected it in the wrong direction or ignored ground.
Signal in to the left or right, signal out to amp in the middle and ground to the left over connector.

Quite simple. If it works as you described, change right and left.

100k should work better, as you don't use a buffer on the input. 10k can be too much load for a weak input signal. I would have choosen 50k or none at all.
 
Thanks a lot for your Answer.

I am pretty sure I have connected it as you described. I have tied the ground(left) pins of the pot and both in and out grounds all together. Could this be a problem?


I could try 50k, I have it on hand, but I don't want to be rotating pots, before I know , I am not doing some basic mistake.

Regards

Adam
 
Hello guys,
probably a stupid question, but I am building a second pair of these modules and I was short on 09-c12 470uf Caps. For some reason Mouser sent me a different type caps - HW(m) instead of HE(m). Both are the same values(cpacity, temp, voltage) as far as I can see, it´s only the size is a bit different.

is it ok to mix these together? for example put two of each on each module. could there be any problem with this?

I don´t want to order these again. it´s too much of a hassle.

Thanks a lot,

adam