OPA604AP

Single JFET-Input Op-Amp DIP-8.3 circuits use this part. Listed as: Single op-amp, DIP8.

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 2), 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
OPA604AP	JFET	9–48 V	20 MHz	25 V/µs	11 nV	5.3 mA	4

FET-input audio op-amp that runs to ±24 V but draws about 5.3 mA.

Fits the same socket

Part	Input	Supply	GBW	Slew	Noise	Iq	Boards	Differs
OPA134	JFET	5–36 V	8 MHz	20 V/µs	8 nV	4 mA	3	FET-input audio op-amp with no offset null; leave pins 1, 5 and 8 unconnected.
TL051	JFET	10–30 V	4.5 MHz	17.8 V/µs	10.8 nV	2.1 mA	8	rated from 10 V. Trimmed-offset upgrade for the TL071/TL081; pins 1, 5 and 8 are no-connect in this revision.
LF356	JFET	?–36 V	5 MHz	12 V/µs	12 nV	5 mA	14	JFET single drawing about 5 mA; specified at ±15 V.
TL071	JFET	4.5–40 V	5.25 MHz	20 V/µs	37 nV	1.4 mA	178	JFET input; this revision shows pins 1, 5 and 8 as no-connect on the DIP, so no offset trim.
TL081	JFET	4.5–40 V	5.25 MHz	20 V/µs	37 nV	1.4 mA	20	JFET input; this revision shows no offset-null pins on the DIP.
LM308	bipolar	10–36 V				0.3 mA	96	bipolar input; needs a compensation capacitor across pins 1 and 8; rated from 10 V. Needs a compensation capacitor (30 pF typical) between pins 1 and 8; the cap sets slew rate and tone.
LF355	JFET	?–36 V	2.5 MHz	5 V/µs	20 nV	2 mA	1	much slower. Lower-power, slower sibling of the LF356.
NE5534	bipolar	10–30 V	10 MHz	13 V/µs	4 nV	4 mA	44	bipolar input; needs a compensation capacitor across pins 5 and 8; rated from 10 V. Compensated for a gain of 3 or more; below that it needs a capacitor (22 pF) between pins 5 and 8.
CA3140	mosfet	4–36 V	4.5 MHz	9 V/µs	40 nV	4 mA	12	MOSFET input; input range reaches the negative rail. MOSFET input that reaches 0.5 V below the negative rail, internally compensated; draws about 4 mA.
CA3130	mosfet, RR out	5–16 V	4 MHz	10 V/µs		10 mA	54	MOSFET input; needs a compensation capacitor across pins 1 and 8; 16 V max, not for 18 V; input range reaches the negative rail; rail-to-rail output. Needs a 47 pF capacitor between pins 1 and 8 for unity-gain stability (15 MHz uncompensated) and is limited to 16 V total supply.

Circuit	Based on	Category	Vendor	Box	Knobs	Price	BOM
Thorpy Fx The Warthog. Vero17×16 Verified 2N5457 · BS170 · OPA604AP Thorpy Fx The Warthog	Thorpy Fx The Warthog	Distortion	Dirtbox Layouts	—	4	—	31
Razorback 2N5457 · BS170 · OPA604AP Thorpy Fx The Warthog · 1590B	Thorpy Fx The Warthog	Distortion	Fuzz Dog	1590B	4	£36.00	40
Pumbaa Distortion 2N5457 · BS170 · OPA604AP ThorpyFX Warthog Distortion · 125B	ThorpyFX Warthog Distortion	Fuzz	PedalPCB	125B	4	$8.00	40