Heya everyone, yesterday i ordered single LM1876T chip to change TDA7265 wihich sounds terrible, speakers are rubbish too Defender mk35 somekind of Hi-Fi they say...
Well i removed the preamp JRC4558 known as worst opamp known to man but great for guitar applications.
Now i designed single sided PCB with fillet plane ground...
Now sure if everything is okay, well... PINout taked from datasheet and also SCH
they say LM1876B pinout is shown...
Heres the PCB ive designed, may have lots of mistakes...😱
Non inverting or negative - input caps 2,5mm ones on board are hooked with ground.
Also there are few jumpers one on input other on the output side.
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Well i removed the preamp JRC4558 known as worst opamp known to man but great for guitar applications.
Now i designed single sided PCB with fillet plane ground...
Now sure if everything is okay, well... PINout taked from datasheet and also SCH
they say LM1876B pinout is shown...
Heres the PCB ive designed, may have lots of mistakes...😱
Non inverting or negative - input caps 2,5mm ones on board are hooked with ground.
Also there are few jumpers one on input other on the output side.
free image hosting
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How about star grounding ? If mute=not connected then take care about pop. You don't need Rin ? Is it possible to move Cs (electrolytic + ceramic) to power pins ?
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Yeah, star grounding may be best solution, right now i have thin rail going to pin 10...
We can move everytihing on board, im new to this PCB designing thingy, well i have made few amps, DAC's, preamps and so on but making PCB with minimal amount of space and without knowing what the heck is the difference between LM1876T and B
Took pinout from B type...
We can move everytihing on board, im new to this PCB designing thingy, well i have made few amps, DAC's, preamps and so on but making PCB with minimal amount of space and without knowing what the heck is the difference between LM1876T and B
Took pinout from B type...
This is LM1876T i was sure it not sealed.
What to i need to to with mute function?
Just leave it?
What to i need to to with mute function?
Just leave it?
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The two film caps on the +ve & -ve rails are in the wrong place.
They should be on or at the Power Pins of the Chip.
They should be on or at the Power Pins of the Chip.
Using a groundfill means you'll get crap sound because the noise currents from the input socket are going via the caps (C1, C? unmarked) to gnd. Shared ground impedances suck worse than TDA7265s for sound. I get fairly decent sound out of the bass/mid driven by my TDA7265s, the tweeter sound though is very, very dull.
Star grounding is what I'm suggesting, every return to GND is individual, none are shared paths.
WoW, i just fried my chip abit....
Had tiny piece of aluminium left on my heatsink when i droped some paste on it...
Now it went hot ~100°C.. it works, at least right channel does
But left one will start distorting at around 0,5-1W not before somekind of protection circuit turns on, well, time to order new chip...
Really, it puts out 2W at least as normal sound and protection shut...
But going over the limit turns it on and it starts distorting again.
10€ for such chip isnt bad at all, th sound is super nice and smooth.
Totally worth it.
Should i order 3 new "original" from ebay or 1and a half from local store...
If i burn even the second one, which i may never burn i have new one right on the way or again, need to order another...
The problem could be my sound card, i hooked up my sisters chool project 22W bridge amp to the same output of the PC, it distorted alot, the amps input resistance is so damn low 470R..
Not sure why... yet it distorts but with other it sounds damn sweeet, like my own but 22W bridge.... more like 5W peak
Had tiny piece of aluminium left on my heatsink when i droped some paste on it...
Now it went hot ~100°C.. it works, at least right channel does
But left one will start distorting at around 0,5-1W not before somekind of protection circuit turns on, well, time to order new chip...
Really, it puts out 2W at least as normal sound and protection shut...
But going over the limit turns it on and it starts distorting again.
10€ for such chip isnt bad at all, th sound is super nice and smooth.
Totally worth it.
Should i order 3 new "original" from ebay or 1and a half from local store...
If i burn even the second one, which i may never burn i have new one right on the way or again, need to order another...
The problem could be my sound card, i hooked up my sisters chool project 22W bridge amp to the same output of the PC, it distorted alot, the amps input resistance is so damn low 470R..
Not sure why... yet it distorts but with other it sounds damn sweeet, like my own but 22W bridge.... more like 5W peak
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LMFAO!
I ordered these damn chips and were thinking of making crossovers of these cheapy speakers...
Well, i found that distortion came from broken voicecoil, 1" 8ohm big and badass voice coil got killed by 20W rms, lol.
I clued it back to place also made crossovers and added some support to enclosures making them way stronger and padded all walls, also i had two nice and smooth 2" port tubes laying around, used them as permanent solution of that epic port noise from old ones, i broke them when taking them off, weakest kind of plastic ive ever seen...😡
BTW, the amp is in perfect shape running super nice and smoooootthhh 🙂
Changed input caps to 1uf 400v audyn's caps+ rk27 pot.
Damn sweet sound
I ordered these damn chips and were thinking of making crossovers of these cheapy speakers...
Well, i found that distortion came from broken voicecoil, 1" 8ohm big and badass voice coil got killed by 20W rms, lol.
I clued it back to place also made crossovers and added some support to enclosures making them way stronger and padded all walls, also i had two nice and smooth 2" port tubes laying around, used them as permanent solution of that epic port noise from old ones, i broke them when taking them off, weakest kind of plastic ive ever seen...😡
BTW, the amp is in perfect shape running super nice and smoooootthhh 🙂
Changed input caps to 1uf 400v audyn's caps+ rk27 pot.
Damn sweet sound
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