LM1875 or TDA7498 For good clean sound (Boards shown in the post)

[r_kalar_2]

In my country, the voltage fluctuates between 210v to 240v. I don't live in Europe. This old transformer will be used for the testing purpose only. I'll replace it later.

 

[r_kalar_2]

This is the LM1875 board and circuit diagram they are sending me.

 

[availlyrics]

The 7812 regulator might be for supplying 12V to relay. As the UPC1237 works above 25V DC. If possible scan & upload both sides of PCB. Beware of fake LM1875.

 

[r_kalar_2]

Availlyrics, thanks for the input. This is the picture of pcb. Yes, one of the main concern is about the ingenuity of the IC. If they turn out to be fake, I have to order directly from TI. As you probably know, it is very difficult to find a genuine ic here in my country.

 

[r_kalar_2]

I couldn't find any schematic that could resemble this pcb. No 1 Mohm resistor across input. Gain settings set at 24x looks like. If any one has any input regarding this board, please mention. Thanks.

 

[nenad88]

this one is good Kit Handmade 20W New Stereo Audio HIFI Amplifier Module LM1875T Mono Channel | eBay

 

[asuslover]

lm1875t chip is 3$ from a reliable seller. You buy that 2$ kit/board from ebay just to practice your soldering...

 

[FauxFrench]

Absolutely an attractive price. But, notice what is written on the PCB:
"LM1875T TDA2030A¨. My understanding of this printing is that it is either an LM1875T or a TD2030A. LM1875T corresponds somewhat to a TDA2050, not to a TDA2030A.
So, you risk receiving a TDA2030A which is inferior. OK, the price is really low.

 

[r_kalar_2]

this one is good Kit Handmade 20W New Stereo Audio HIFI Amplifier Module LM1875T Mono Channel | eBay

Seller doesn't ship to my country. Not a problem though. Many boards like this one available on eBay/AliExpress.

Asuslover, They'll cost me around 2.5 USD per board. So 5 USD for 2 board. Ic will certainly be fake. So 7 USD more for two authentic ic. Some good quality cap and a bridge rectifier for psu will cost me around 9 USD. Total 21 USD without speaker protection, without replacing those otb components. So, it isn't a cheaper route. But for soldering practice, may be. Also my board won't come pre-soldered.

 

[nenad88]

boards are good i dont care about ebay ic or components

 

[r_kalar_2]

nenad88, then this is better option.
TDA2030/TDA2030A/LM1875T/ LM675 Audio Power OCL BTL Amplifier PCB Board for DIY | eBay

 

[nenad88]

That board doesnt have all needed components.

 

[r_kalar_2]

Yes, it's a bare pcb. Just buy components as needed and populate it. Enjoy.

 

[r_kalar_2]

Can any one recognise if these(from two different seller) are genuine or fake?

 

[asuslover]

A picture of 2 lm1875 100% authentic(unless ti.com sells fakes)

 

[r_kalar_2]

Thanks asuslover. Really appreciated.

 

[vj_audio]

Hi

This Aliexpress looks genuine:

( 2 pcs/lot ) LM1875 Audio 20 Watts Power Amplifier IC, LM1875T.-in Integrated Circuits from Electronic Components & Supplies on Aliexpress.com | Alibaba Group


The cost is more than original chip selling in India from reputed distributors such as TI and Rsdeliver.

Once I emailed this seller and asked him why is he selling LM1875 (2 pieces) at ebay.com for 7.99 USD whereas the cost of the same is 12.20 USD on Aliexpress.com?

Ans: "Dear friend,
If you chose free shipping, we will use economy shipping service, no tracking number.

Thanks
Lily"

Here is the ebay.com link

2x LM1875 Audio 20 Watts Power Amplifier IC, LM1875T | eBay

 

[r_kalar_2]

I know this one. Electronics salon I guess or something like that. He charges around 4 USD flat shipping rate for as many ic you want when you buy from AliExpress and free shipping when from eBay to my country. Thanks for reassurance though.

 

[r_kalar_2]

Which one is correct?

In the data sheet of lm1875 on page 2, Junction to Case temperature is been given as 3°C/W. But on page 8, while calculating the required heatsink it is been given as 2°C/W. Which one is correct?

 

[AndrewT]

The page 2 value is in the Absolute max ratings.
3C/W is the absolute max.

Page 8 uses a typical value of 2C/W for the calculation.