[sdiy] The TL074 has changed!

[Jay Schwichtenberg]

Mike,

Would you please share your experiences about the new chip not working 
for you?

Thank you.
Jay S.

On 8/1/2025 5:23 PM, Mike Beauchamp wrote:
> Last week I received an order of partially assembled prototype PCBs. 
> It's a rather large circuit, with the bulk of the IC's being the 
> venerable Texas Instruments TL074C that I've been using for 15 years.
>
> Compared to the previous boards, I immediately noticed that the power 
> consumption was way lower on this batch - from ~16W down to 11.8W, 
> definitely significant. That is about 1/4W less power per TL074.
>
> After some snooping with the help of people on forums, it seems as 
> though Texas Instruments changed fab processes ( 
> https://media.digikey.com/pdf/PCNs/Texas%20Instruments/PCN20221219006.1.pdf 
> ). The new version has been around for a while as the TL074H, marketed 
> as an "improved version", but according to the latest datasheet from 
> July 2025 ( https://www.ti.com/lit/ds/symlink/tl074h.pdf ) Table 9-1 
> Page 34, the new die is now being used in all of the other TL074s 
> (except TL07xM):
>
> TL07xH - is the new version
>
> TL07xM - will still be the old version
>
> TL07xA, TL07xB, TL07xC and anything else - can be either the new or 
> old version with no way of telling.
>
>
> One part of my circuit started working incorrectly with the new 
> version, but it was relying on an edge-case near phase reversal. I've 
> since revised the circuit to work correctly with the new and old 
> versions, but this makes me wonder how the change to this op-amp might 
> effect sensitive circuits, or those creative uses we see in synths, 
> audio and pedals often. It also seems like the new version has a lot 
> more low frequency noise as well.
>
>
> Thoughts?
>
> Mike
>
>
>
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