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
flick
open top
rich harmonics
ADOA
edgy highs
punchy mids
NDOA
thick
warm
sound
JDOA
nice low end
openess
QDOA
gentlemanly
sound