[sdiy] The TL074 has changed!

[Vladimir Pantelic]

I'm at the beach, collecting sand to make the glass bulbs as we speak

On Mon, Aug 4, 2025, 13:10 mark verbos <markverbos at gmail.com> wrote:

> You aren’t using tube gain stages? Are yours even analog?
>
>
>
>
> On Aug 2, 2025, at 13:36, Vladimir Pantelic via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
> don't you all build your own discrete opamps???
>
> On Sat, Aug 2, 2025, 13:20 Doug Jackson via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>> TL074....  TL074...
>>
>> We all know that Gods own opamp is the 741...
>>
>> Get off my lawn :-)
>>
>> On Sat, 2 Aug 2025, 7:04 pm Mike Bryant, <mbryant at futurehorizons.com>
>> wrote:
>>
>>> 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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