discrete operational amplifiers

we have developed several fully discrete operational amplifier flavors in the 2520/990 footprint, some original and some adaptations of legacy iconic designs.

M2 and flick designs are available for purchase through our web store.

If you are interested in the other designs, please shoot us an email so we can check our inventory.

OpAmp comparison table

Name	Description	Design Remarks	Sound	Transistors	Operating Voltage
M2	original design inspired by Melcor 1731 output stage	cascode amplification stage with quasi-complementary output	clean, warm, solid	11	±12V to ±24V
flick	original inspired by Flickinger 290-3 mic pre cards	differential amplification followed by all NPN output	open top with rich harmonics	6	±15V to ±24V
ADOA	our take on the most famous American discrete op amp	differential amplification with complementary output	edgy highs and punchy mids	8	±12V to ±20V
JDOA	adaptation of Jensen 918	darlington amplification stage with complementary output	nice low end and openess	9	±15V to ±24V
NDOA	adaptation of highly configurable German design	common emitter amplification stage with complementary out	thick warm sound	12	±2.5 to ±22V
QDOA	adaptation of a classic American op amp used in southern California large format consoles	novel gain stage with complementary out	gentlemanly sound	10	±14 to ±28V

M2

clean

warm

solid

ADOA

edgy highs

punchy mids

NDOA

thick

warm

sound

flick

open top

rich harmonics

JDOA

nice low end

openess

QDOA

gentlemanly

sound