[sdiy] The TL074 has changed!

[Mike Bryant]

I'll add to this - the new one is crap !!   I used to use the TL07x series in low cost mic-amps and other mixer circuits but the H series are noisy as hell.   I just specify other manufacturers now.

They really should have given this opamp a different part number - it's simply not a compatible device, even if it fixes known issues.
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Jay Schwichtenberg via Synth-diy <synth-diy at synth-diy.org>
Sent: 02 August 2025 06:30
To: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] The TL074 has changed!

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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