about LM675T

According to the national data sheets:


the LM675T is in a NS TO5D case, where as the LM1875T is in an an NS package number TA05B case. These appear to be the same as far as the PCB is concerned, but the leads are "bent" 90 degrees on the 1875, making it more suitable to for a horizontal bolted-through-the-board heat sink, whereas the 675 looks like it'd be happier with the upright style, either bolted freely to the package (it doesn't look it'd much heatsinking), or to an off-PCB heatsink (e.g. chassis-mount).

Caveat: I know nothing of these two chips, other than what I read [quickly] in the data sheets.

It's tough to say whether you're buying a fake or not, but I don't see National listing a part with straight legs. Is it stamped as a National Semiconductor part?

It is certainly possible that there are unlicensed Chinese clones floating around out there. There are a lot of very clever people over there, I remember years ago finding out that I had bought a batch 486DX2-66 chips which were actually 486DX2-50s, with the tops "planed" and re-stamped in China (came through an HK supplier). Boy was I upset, those chips were $660 each back then.

I would test the chip, and if it works, use it. Would you mind posting a photo?

i like lm1875's sound quality, i think it may be the best chip amplifier (including lm3875,lm3886,tda7294...and so on),the only one disadvantage is that its output power is too small, from the internet,i find lm1875 could be direct replace by lm675,and the latter has higher quality in low frequency response and bigger output power, i also find that lm675 is recommended by many senior HI-FI fans abroad. so I'm interesting with it. in China's market, it's difficult to find lm675, it took me several months to get two piece, but i haven't do any esperiment on them.
dear friends:
have you use it? tell me your result, thank you!