Voltage regulator ID

Hello,
I have (what looks like) a voltage regulator for a Boss DD-500 guitar pedal that needs replacement. It only has the markings J04 and also some code of dots, which would probably help if I knew how to decode it.

It’s surface mount with pads that stick out the sides at the bottom, but the chip itself has about a 2.3x3mm footprint, pictured.

Can anyone identify this, and/or know the code?
Thanks!
Zack

Hello, Zack.

Do you have any idea of the specifications for this device? Voltage input or output, current levels, anything? I’m not able to find any useful information on the “J04” mark alone, sorry.

If I were to hazard a guess, I’d say it’s more likely an op-amp than a regulator, but I could find nothing with such markings to help. A schematic is probably going to be required to figure it out.

All I could locate is below. It might be a good start.



https://www.hobby-hour.com/electronics/s/od1-overdrive.php
But is for Model Boss OD-1 OverDrive

• IC: RC3403ADB, uPC4741C, NJM4558D, uPC4558C, uPC4558C, TL4558P, JRC4558D, JRC4558DD, JRC4558DC or C4558C (depending on your model)
https://www.digikey.com/short/zh892z What we have for op amps

• Q1: 2SK30ATM-Y (N-channel JFET transistor)
• Q2: 2SK30ATM-GR (N-channel JFET transistor)
• Q3, Q4, Q5: 2SC945-P 2SC1815-Y (NPN silicon transistors)
• Q6, Q7: 2SC732TM-GR (NPN silicon transistors)
• D1: RD11EB-3 (500mW 11V Zener diode)
• D2: RD5.1EB-3 (500mW 5.1V Zener diode)
• D3-D10: 1S2473 or 1S1588 (switching diodes)
• D11: SLP135B (LED)

Thanks, everyone.

I’m not certain it’s a voltage regulator, but it comes very early in the power stage, and the symptom this has is no response to power. I don’t think it’s an op amp.

This is a digital pedal and pretty different than an OD-1. Thanks for trying/looking for that and a schematic; I could’t find one either.

These tend to have a few DC voltages in them after the power stage, 3.3, 9, often 5v. It’s 9VDC input.

I doubt I’ll get info from Boss but will try with them. Too bad that code of dots didn’t mean something to you all.
Thanks!
Zack