TL974

Quad BJT-Input Op-Amp DIP-14 / SOIC-14.1 circuit uses this part.

Datasheet · from ti.com

Substitutes same socket

Parts that fit the same socket: the same function, pin count and pinout. The figures are read off each part's datasheet (this one's from page 6), typical where the sheet gives a typical value, otherwise the maximum. Closest first; the last column says what differs. A different part can change the sound, and a circuit may lean on one particular figure, so read the build document's notes before you swap.

This part

Part	Input	Supply	GBW	Slew	Noise	Iq	Boards
TL974	RR out	2.7–12 V	10.6 MHz			2.48 mA	1

Low-noise quad (4.4 nV/√Hz at 100 kHz) limited to 12 V total; it will not survive an 18 V rail.

Fits the same socket

Part	Input	Supply	GBW	Slew	Noise	Iq	Boards	Differs
TLE2074		4.5–38 V	10.6 MHz	32 V/µs	17 nV	2.4 mA	20	Fast, low-bias quad drawing about 2.4 mA per amplifier; the input range reaches the positive rail but stops 4 V above the negative one.
TL074	JFET	4.5–40 V	5.25 MHz	20 V/µs	37 nV	1.4 mA	315	JFET input; inputs must stay 4 V above the negative rail.
TL084	JFET	4.5–40 V	5.25 MHz	20 V/µs	37 nV	1.4 mA	15	JFET quad; inputs must stay 4 V above the negative rail.
MC33179	bipolar	4–36 V	5 MHz	2 V/µs	7.5 nV	0.425 mA	2	Quad version of the MC33178 in the standard quad pinout.
LF347	JFET	7–36 V	3 MHz	13 V/µs	18 nV	2 mA	20	JFET quad; common-mode range must stay 4 V inside each rail.
TLC2274	CMOS, RR out	4.4–16 V	2.25 MHz	3.6 V/µs	9 nV	1.2 mA	1	input range reaches the negative rail. CMOS rail-to-rail-output quad limited to 16 V total.
LMC660CN	CMOS, RR out	4.75–15.5 V	1.4 MHz	1.1 V/µs	22 nV	0.4 mA	4	input range reaches the negative rail. CMOS quad limited to 15.5 V total; rail-to-rail output and an input range that includes ground.
3403	bipolar	5–30 V	1 MHz	0.6 V/µs		0.7 mA	17	input range reaches the negative rail. 741-class quad that runs from a single supply; the input range includes the negative rail and the output has a class AB stage.
LM324	bipolar	3–30 V	1.2 MHz	0.5 V/µs	35 nV	0.35 mA	100	input range reaches the negative rail. Input range includes the negative rail and the output nears ground, but it is slow and shows crossover distortion.
LM348	bipolar	8–36 V	1 MHz	0.5 V/µs		0.6 mA	2	Four 741-class amplifiers in the LM324/TL074 pinout.

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Multiwave Mega ATTINY84() · ATTINY85() · CD4040 · CD4040BE 1590BB	—	EQ / Filter	Parasit Studio	1590BB	4	—	64