LM1875 still relevant ?

[sdk]

thanks mbhangui.

I choose to not believe in psychoacoustic as my hearing of high frequencies is gone, and for such things 'dimaag ko jis taraf mod do mood jata hai'. For bad recording I would like to use tone controls thats enough to experience music.

A forum friend has offered free ICs and another friend has offered well thought schematic. So I think LM1875 is pretty much fixed. I may need help on PCB design as I like neat DIY.
Thanks again for suggestions.

If you want to make the amp from scratch then go here

Amplificador de 60W con Control de Tonos y Volumen

Amplificador estéreo de armado sencillo, compacto y de bajo costo. Excelente amplificador estéreo de 60 Watts, ideal para videorockolas o para uso casero.

www.videorockola.com

Google will translate automatically

 

[Hiten]

thanks sdk
will check that link.
regds

 

[Hiten]

you want to make the amp from scratch then go here

I checked that though it is good making PCbs and procurring parts will be complicated. But thanks
----------------------------------------
Anyone interested in group buy of these ICs. ?
regds.

 

[VIPINSAINI20]

I'm planning to make my own LM1875 PCB. bought ICs from lamington in 2014, at various rates Rs 50-60-75/- each from multiple shops, Probably all were fakes . One IC (Rs50 from RK) had HF oscillations, Tweeter used to make distorted clipping sound. replaced it with Ic brought from another shop, it worked well. I had used veroboard. Sound was very good (for supposedly fakes) at +/-12V @6W P. Ch. 4Ohm speaker when compared to Norge TDA2030(Genuine) based amplifier . Tested up to +/-20V on a dual SMPS . DM me , I have some good layouts.
PS Your LM3886 amp was a real beauty!

TDA2050 vs LM1875 performance tests to see which is the BEST​

Can You please post pictures of your LM1875T ICs

 

[VIPINSAINI20]

my friend says he will take a week to seek IC from lamington road. i have asked him to check for genuine he said he will see and buy from known familiar sellers and purchase only if they seem genuine.

meanwhile...
I opened the LM1875 IC I had along with one genuine LM317. The die looks very small compared to real ones posted Here. hardly 2mm x 1.5 mm. where as original has bigger die.
LM317 seems genuine with copper plate. Attaching some pictures.

View attachment 70784

View attachment 70783

regds

Even UTC TDA2050L ICs have bigger die inside than this fake LM1875 ic
If any of you need UTC TDA2050L or something else let me know I have TDA2050 ,in 4 types
1. Original ST TDA2050
2. UTC TDA2050L original
3. Triangle D2050 Original bigger die inside than Chinese copy of TDA2050
4. Fake or Chinese st TDA2050

I also have some
uPC1237HA
LM3886TF Original
TDA7294 Original
LM1036N Original
LM1875T National Semiconductor NOS

 

[Hiten]

Even UTC TDA2050L ICs have bigger die inside than this fake LM1875 ic
If any of you need UTC TDA2050L or something else let me know I have TDA2050 ,in 4 types
1. Original ST TDA2050
2. UTC TDA2050L original
3. Triangle D2050 Original bigger die inside than Chinese copy of TDA2050
4. Fake or Chinese st TDA2050

I also have some
uPC1237HA
LM3886TF Original
TDA7294 Original
LM1036N Original
LM1875T National Semiconductor NOS

Thanks bro.
i did managed to get original LM1875s with boards. Boards are almost finished. If time permits today I will take them to a friends place to listen to them.
thanks again for the offer. Will keep in mind components you have. I may need them as I just build budget amps for for fun and listen to them.
regards.

 

[VIPINSAINI20]

Your welcomed anytime you want, I have many different components available.

Thanks bro.
i did managed to get original LM1875s with boards. Boards are almost finished. If time permits today I will take them to a friends place to listen to them.
thanks again for the offer. Will keep in mind components you have. I may need them as I just build budget amps for for fun and listen to them.
regards.

 

[bobbyprajan]

Is genuine LM4780TA available ?

 

[Hiten]

Is genuine LM4780TA available ?

any reason to go for lm4780 ? LM3886 will have better thermal management, Though if you want there are couple of lm4780 ready module for sale on diyaudio. Dont know if they are genuine or not.
regards

 

[bobbyprajan]

any reason to go for lm4780 ? LM3886 will have better thermal management, Though if you want there are couple of lm4780 ready module for sale on diyaudio. Dont know if they are genuine or not.
regards

I have 2 PCB bought long back for the LM4780. I have 2 chips as well but don't know if they are genuine. Should I try building it with the chips I have ?

 

[Hiten]

I have 2 PCB bought long back for the LM4780. I have 2 chips as well but don't know if they are genuine. Should I try building it with the chips I have ?

yes uou can. I guess duplicate ICs have some problem at only full power. At normal to moderate levels it works and may not have much difference.
Be carefull of repeated soldering. PCB tracks may give up. Pins are also very close. Idea is to have soldering iron maximum hot and quickly touch and solder.
regards

 

[bobbyprajan]

yes uou can. I guess duplicate ICs have some problem at only full power. At normal to moderate lavels it works and may not have much difference.
Be carefull of repeated soldering. PCB tracks may give up. Pins are also very close. Idea is to have soldering iron maximum hot and quickly touch and solder.
regards

Thanks. Will try them soon

 

[sdk]

yes uou can. I guess duplicate ICs have some problem at only full power. At normal to moderate levels it works and may not have much difference.
Be carefull of repeated soldering. PCB tracks may give up. Pins are also very close. Idea is to have soldering iron maximum hot and quickly touch and solder.
regards

With my minimal soldering experience i feel that liquid flux is far superior than paste flux even when using rosin core solder. For a newbie like me, the quality of soldering increased dramatically when i switched to liquid flux from soldron

 

[availlyrics]

Can You please post pictures of your LM1875T ICs

Fake LM1875 (Img-1)caused oscillations at high freq. Broken pins (Image 2)due to heavy heatsink. Fake LM3886 (iMG-4 ) was DOA

 

[availlyrics]

I have 2 PCB bought long back for the LM4780. I have 2 chips as well but don't know if they are genuine. Should I try building it with the chips I have ?

LM4780 are obsolete, don't even look for it unless some FM offers them from genuine National sample program. Also LM4780 have their own thermal and channel isolation issues, coz both channels are sharing common package. I have built one, can share photos

 

[VIPINSAINI20]

Image 2 -Broken pins due to heavy heatsink.

When did you buy them?
They looks very old

Here is the LM1876T ,which is available in stocks, seller asked for 350 rupees each, I have some doubts about originality
What are your thoughts about this

 

[availlyrics]

Thanks bro.
i did managed to get original LM1875s with boards. Boards are almost finished. If time permits today I will take them to a friends place to listen to them.
thanks again for the offer. Will keep in mind components you have. I may need them as I just build budget amps for for fun and listen to them.
regards.

Please post photos for comparison purpose. I got them from Lamington rd - RK electronics. Genuine sample was graciously offered by Kuldeep Singh , diyaudio. All are from 2012

 

[bobbyprajan]

LM4780 are obsolete, don't even look for it unless some FM offers them from genuine National sample program. Also LM4780 have their own thermal and channel isolation issues, coz both channels are sharing common package. I have built one, can share photos

The PCB is for parallel configuration. In this case channel isolation should not be a concern, right ?

 

[availlyrics]

When did you buy them?
They looks very old

Here is the LM1876T ,which is available in stocks, seller asked for 350 rupees each, I have some doubts about originality
What are your thoughts about this View attachment 72440

The logo looks good to me, compared to my fake LM1875, it appears a bit compressed. If you have multiple samples, Short circuit survival at full signal and distortion / clipping pattern at full power on an oscilloscope are some of the test. Fake ICs burn out in these test conditions

 

[VIPINSAINI20]

The logo looks good to me, compared to my fake LM1875, it appears a bit compressed. If you have multiple samples, Short circuit survival at full signal and distortion / clipping pattern at full power on an oscilloscope are some of the test. Fake ICs burn out in these test conditions

I knew that much, any physically indication of Original ICs