eBay mono LM1875 kit

Received my kits but are damaged so on hold until I get replacements.

Must have been run over. 😱

Needed the PCBs but the components were going to be thrown out.
 

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lLM1875T chips

When I received the kits I had a look at the chips and compared to the others I had.

A. An Australian supplier who does substitute when original is not in stock. This one has 2 indents on the face, one above pin 1 and the other higher above pin 5. Looks like they have a manufacturing code in them B8/14 and B9/1. Not genuine from TI for sure.

B. As supplied with the kit and the cutouts in the sides looks like that of a TDA2050 from the pic at ESP P72 so unlikely to be a LM1875T.

C. LM1875T/NOPB supplied by Digikey which would be from TI.
 

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Well, I have been more pragmatic. I bought 4 pcb's of which I´m using two as a test bench while saving the other two for the final configuration.

I don't mind using these cheap components to try different things and at the same time I like to see what effect the cheap components have for changing more expensive ones.

I have never had a very clear idea of how to use this amplifier as a headphone amp so I am simply dedicating to do test.
 
V nice clean build.
Don't fully understand Why you are fiddling about with these then? Definitely smaller than a full amp, less shelf space required.
Would be V surprised if an lm1875 cobble up, matched performances to your photo'd build.
My Lm3886 adventures were simply outclassed by My Firstwatt builds.
Better bass, mids and highs , a room deep soundstage was the real eyeopener tho.
Nelson pens a Fine circuit indeed.

If boredom is the impetus .. Perhaps a Lady friend ?
Although those can be exotic and certainly Expensive adventures 😉
 
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DIY is more cheaper and less complicated. 😀😀😀

Returning to LM1845, I am not looking for something better than Papa and Wayne's projects, simply I like play and learn.

I tested a channel with an original LM1875 and indeed, the chip supplied in the kit is a TDA.

The LM1875 is brighter, less warm. I would not rate it as better only different but I need some more time to form an opinion.
 
Hmm... the 1875 'chips' included in MY 2$ amp kits are Definitely Fakes.. Not even passable copies..
Simple visual comparison alone..between these and Genuine (from Mouser) 1875's Left me with zero doubts.
No subtleties involved there.

I recently received a 'Genuine' 5532 chip to replace the 5532 I bought to erm .. replace.. the suspect one included in a 10$ 7377 2.1 amp kit.
I bought the first replacement at the local Chinese run Ebay junk electronics reseller shop. His 5532 looked credible and of course he swore that it was a Genuine part 🙄
Swapped in the Real one.... the audible difference was immediate.

Caveat Emptor 😀
 
hi specialists

Is it possible to look at some scope pics of your original kit and an" approved" kit? i am thinking about ringing or less performance etc...

my kit is original but actually my business weeks are still to much to have power to go ahead with DIY

chris
 
planning.....the housing

Hi


i just play around with the possibilities of a housing (i used this for my TPA3255 "fake amp") and the internal boards.
https://www.amazon.de/dp/B017VIIDN4...ascsubtag=94c08f68c2a4b11d022dd960c5c1d695_CT


pic1 160VA with its dimensions (i bought a 300V for a other project) + big rectifier board + both channels - here is the room for the amp boards limited and t1 board is near to the transformer - not good

pic2 the same but with small psu board (rectifier and caps - no crc..) - here its better for short input signal ways.
oh...yes the transformer should be placed in the middle 😉
pic 3 is just the size of the heat sink = 6cm and the height of the board with possible stands and the lm1875.
pic 4 is the front panel -i like this kind of housing🙂


chris
 

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