Hello, I have been (stupid enough to ?) buying my
second K8055 kit.
The opamp TLV274 in my first kit had an input offset making it insensitive for one of two channel inputs.
The one that was sensitive has done me good job.
Now in my second kit both the inputs are less sensitive than the “non sensitive” input in my previous kit, which then make the circut no so useful.
Where can I buy other TLV274s for substitution, what will they amount to. (guess I will have to rely on manufacturing spread for sensitivity)
What exactly you mean with “insensitive”? On the original K8055, the 274 is configured as a pure voltage follower. Did you turn the ATT potentiometers all the way clockwise? Do you have a digital voltmeter? If so you can apply a 5V input (you can take that from the upper post of SK2 or SK3) to I1 and I2, then try to find out where exactly the voltage drops. Is it at pins 3/5 or is it at pins 1/7?
If you are in North America I suggest bookmarking Mouser. If not please tell us at least the country.
I have only had good experiences when ordering from Mouser. They ship fast and at reasonable shipping fees. And they have data sheets for pretty much everything.