LM348

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 3), 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
LM348	bipolar	8–36 V	1 MHz	0.5 V/µs		0.6 mA	2

Four 741-class amplifiers in the LM324/TL074 pinout.

Fits the same socket

Part	Input	Supply	GBW	Slew	Noise	Iq	Boards	Differs
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.
JRC2902	bipolar	3–32 V	0.5 MHz	0.5 V/µs		0.25 mA	2	input range reaches the negative rail. LM324-class single-supply quad with crossover distortion; the DIP14 (NJM2902N) is listed as discontinued.
LF444	JFET	?–36 V	1 MHz	1 V/µs	35 nV	0.15 mA	4	JFET input. Low-power JFET quad at about 150 µA per amplifier.
TLC2264	CMOS, RR out	4.4–16 V	0.73 MHz	0.55 V/µs	12 nV	0.21 mA	3	CMOS input; 16 V max, not for 18 V; input range reaches the negative rail; rail-to-rail output. 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	CMOS input; 15.5 V max, not for 18 V; input range reaches the negative rail; rail-to-rail output. CMOS quad limited to 15.5 V total; rail-to-rail output and an input range that includes ground.
MC33179	bipolar	4–36 V	5 MHz	2 V/µs	7.5 nV	0.425 mA	2	much faster, may oscillate in a slow part's place. Quad version of the MC33178 in the standard quad pinout.
TL064	JFET	10–30 V	1 MHz	3.5 V/µs	30 nV	0.2 mA	17	JFET input; rated from 10 V. Low-power JFET quad at 200 µA per amplifier.
TL974	RR out	2.7–12 V	10.6 MHz			2.48 mA	1	12 V max, not for 18 V; rail-to-rail output; draws 2.48 mA per amplifier; much faster, may oscillate in a slow part's place. Low-noise quad (4.4 nV/√Hz at 100 kHz) limited to 12 V total; it will not survive an 18 V rail.
TLC27M4AIN	CMOS	3–16 V	1.1 MHz	4.5 V/µs	32 nV	0.06 mA	8	CMOS input; 16 V max, not for 18 V; input range reaches the negative rail. Low-power CMOS quad limited to 16 V; the input range includes the negative rail (single-supply friendly).

Faceplate	Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
	Cookbook Phase Shifter 741 · AM9709CN · LM348 · LM741	—	Phaser	Experimentalists Anonymous	—	3	—	26