AORTA

Key characteristics

Benefits in VFB amplifiers

Super-Beta transistors in OTAs?

http://www.righto.com/2016/12/inside-lm108-op-amp-superbeta.html

https://www.diyaudio.com/forums/solid-state/202031-questions-transistors-beta-hfe-3000-darl-topology.html

Yesterday I found a few LM13700s sitting around, which lead me to this interesting two part mini-series about OTAs, from gain control and voltage-controlled filters to voltage-controlled oscillators. It's an amazing subject:

UNDERSTANDING AND USING ‘OTA’ OP-AMP ICs

by Ray Marston

Part 1

https://www.nutsvolts.com/uploads/magazine_downloads/11/April%202003%20Ray%20Marston%20-%20Understanding%20and%20Using%20OTA%20Op-Amps.pdf

Part 2

https://www.nutsvolts.com/uploads/magazine_downloads/11/May%202003%20Ray%20Marston%20-%20Understanding%20And%20Using%20OTA%20OP-Amps.pdf

Currently we've got BC847DW and BC857DW in SOT-363 (SC70-6) with 0.65mm pitch but this one is even smaller with its 0.5mm pitch. It's also matched to within 10% gain and 2mV V_BE offset. 10ct/pc in 1k quantity at Mouser.

Other contestants: BC857BS, MMBT5401