80's uA772

[DnD]

Ciao
Again from my dad's stock I've found some uAF772TC dated 8006, and some uA741 same period. Willing to use 741 I've built a DOD250 gray box but I've used a layout of a newer version with 4558......so I've put in TL072, TL082 and uA772.....to make some try having not a 4558. At my ears 772 in this build is better sounding than TL's. My question is: why I cannot see many 772 used for kinda circuits?
Thanks
DnD

[anotherjim]

Don't think I've ever seen one of those. I can't find proper data for it. I found a suggestion it's like a TL082 but without the data? Hmmmm...

[antonis]

Looks more like LM1458 equivalent..
https://www.datasheetarchive.com/pdf/download.php?id=790f9c5e286aec383053728a0b19067e0c250a&type=M&term=UA772

[anotherjim]

Looks more like LM1458 equivalent..
https://www.datasheetarchive.com/pdf/download.php?id=790f9c5e286aec383053728a0b19067e0c250a&type=M&term=UA772

If it sounds good in a fuzz, then it probably is a lot like a dual 741, or a 1458 in other numbers.

[Rob Strand]

The UAF772 (Fairchild) isn't common but I've see it in the past.  In the back of my mind I thought these were functionally equivalent to TL072's (TI).  Not sure what device came first. 

https://datasheetspdf.com/datasheet/UAF772.html

The key thing here is the JFET input.  The commonality goes a bit deeper as they used to be call "BiFET" opamps.

As to comparing the internal circuits, there are similarities and differences.  You have to watch out because some internal circuits are simplified and some are not.

Looks more like LM1458 equivalent..

In that list the HA-2510 part is a bipolar device but it is fast.  The basis for Harris's equivalence might be speed but it won't match leakage for example because it's bipolar.   There could be a difference between UA772 being bipolar input and UAF772 being JFET which is confusing things.


OK from this datasheet it looks like the UA772 is also JFET input,

https://www.datasheets360.com/part/detail/ua772tc/-4965422367624622113/