[sdiy] The TL074 has changed!

[Mike Beauchamp]

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