hello folks !
I was going to buy an lm1875 mini ref pcb from Linuxguru, but he is very difficult to be reached, so i got this pcb from ebay....
I dont have a schematic, i would love to know if any of you guys tried this pcb before.
I was going to buy an lm1875 mini ref pcb from Linuxguru, but he is very difficult to be reached, so i got this pcb from ebay....
I dont have a schematic, i would love to know if any of you guys tried this pcb before.
Attachments
There are a few kits similar to the above example. They all have a problem with closely packed sections that run too close together and often the output is within 2cm of the input which causes problems with distortion and stability. Sure, it minimises cost and makes it compact that way but there are usually more important requirements for our DIY projects.
I'm not endorsing the example linked here, as I haven't used one but you get the picture of what may be considered better layout practice for optimum, clean performance: Assembled Stereo 40W LM1875 SK3875 Audio Integrated Amplifier Board | eBay
I'm not endorsing the example linked here, as I haven't used one but you get the picture of what may be considered better layout practice for optimum, clean performance: Assembled Stereo 40W LM1875 SK3875 Audio Integrated Amplifier Board | eBay
thanks Ian, i do not believe that is a perfect layout , but I didnt have the too many lm1875 pcb options .
The one you pointed to me looks good, but its assembled , and it's actually very confusing, it is called sk 3875 but it is using lm1875 chips not lm3875 as , i think, most of us would believe....
The one you pointed to me looks good, but its assembled , and it's actually very confusing, it is called sk 3875 but it is using lm1875 chips not lm3875 as , i think, most of us would believe....
Here's the Schematic
View attachment LM1875_Current_FB_Board.pdf
I bought one of those boards and drew out the schematic. It has current FB.
View attachment LM1875_Current_FB_Board.pdf
I bought one of those boards and drew out the schematic. It has current FB.
If you look closely at the PCB, the Chips are mounted flat below the board, as with many flatpack transistor builds. It's actually quite a delicate operation to re-form the pins without fracturing them where they were sharply kinked, in order to mount them flat.lm1875 chips not lm3875
Making it easier, SK3875 are cloned LM1875 chips but they have unformed pins and full encapsulation to simplify the mounting procedure, as you see in the pic here and with larger chips like LM3886, LM3875 that also come in isolated packages.
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