polvo

Thanks for the suggestion anyway though. I was hopeful it would let me solve the problem without having to do any more of my horrendous soldering...

An update for anyone still following this, or for anyone who might have this same issue in the future... Lots of suggestions have been made in this thread, I decided to start with the easiest one to see if this worked: Bought one of these Lehle DC filters, but it doesn't solve the problem. Next up, I'm going to try this:

By "preamp switched out" do you mean the active/passive switch set to passive? Because I do still get a pop in that case. But no pop when I remove the battery. I'm still a bit confused about what conclusions to draw from that.... So are you suggesting that replacing the capacitor in the preamp circuit board might not solve it? What about the suggestion to add a separate capacitor in front of the output jack?

No, I still get the pop even when switched to passive. It only stops with volume at 0% or with the battery removed.

Just checking I've understood this... Would something like this be what I need? https://ebay.us/m/EnJIZt And where in the circuit would it go? Between volume and output jack? Or immediately after preamp?

Replied above - yes, reducing volume to 0% is a workaround for now. I've been putting up with it for a while but with some big gigs coming up I've now decided it's no longer "acceptable procedure"! Pics above - but I don't really know what I'm looking at and can't see anything recognisable to me as a capacitor. Sounds like that (or the pedal version posted by @chyc) might be less fiddly than replacing the capacitor inside the preamp circuitry, and a cheaper solution that replacing the entire preamp. Will check it out, thanks.

Thanks for all the replies. Here's a bit more info and some photos.... The problem does not occur when volume knob is turned to 0%, or when the battery is removed. It does still occur when the battery is plugged in but the active/passive switch is set to passive. (This means at least I have a workaround as I can just roll of the volume between songs to activate switches.... but that's not really helpful in the middle of a song!)

Also getting the same issue across different power supplies. I was previously using one that gave me a lot of buzz when gigging so I recently switched to a Cioks PSU in the hope that would solve all my noise problem. It completely cleared up the buzz, but I'm still getting the pops. Haven't tried batteries on the pedals... that's not gonna be a sustainable solution but worth testing out just to see if it makes any difference. I'll test that later today.

It's a Cort B4 Plus AS RM bass. Tested with multiple different pedals and amps, it repeats the same issue with all of them.

Sorry for a kind of cryptic subject line. I've been down a bit of a chatgpt rabbit hole trying to figure out what's going on here, but I don't know if I can trust what it's telling me. Think I need some human input on this one! Problem: I get a loud pop when turning my pedals on or off. This is only on one particular bass. Likely cause (according to chatgpt): Output coupling capacitor is likely leaky or failing, causing DC leakage and popping. BUT My bass has nothing that looks like the replacement capacitor I found online (e.g. https://ebay.us/m/62aZgK). It's a Cort B4 Plus AS (wiring schematic here: https://www.cortguitars.com/wp-content/uploads/2024/07/cort-b4-plus-as-basses-schematic.pdf). My questions for the wise heads of basschat: Based on the tests I've done (listed below), is the capacitor likely the problem or is chatgpt hallucinating? If not, what else could I try? If I can't see a capacitor, does that mean it's likely build into the circuit board of the active electronics module? And if so, is that something I could realistically fix myself with basic soldering skills? Tests I've done to identify the cause of the problem (summary by chatgpt): Measured DC voltage at output jack: ~1.75-2.0 V DC present with battery, 0 V without battery (confirms DC leakage). Battery voltage verified healthy. Output jack switching continuity: Functioning as expected, switches battery ground on connection. Push-pull active/passive switch continuity tested: Switch behaves correctly on both positions. Pickup resistance measured at circuit board inputs: Neck pickup ~3.25kΩ, bridge pickup ~9.2kΩ (normal ranges). Output coupling capacitor tested for DC leakage with multimeter: Resistance readings 0.3 MΩ and 0.046 MΩ, lower than ideal for a blocking capacitor, suggesting leakage. Battery connected vs disconnected test: DC leakage present only with battery connected, consistent with capacitor leakage causing DC to output.

Ah ok makes sense, thanks

Just picked up this beauty, a 1987 reissue of a JB-62. I'm partly just posting here to show off, of course, but also because it has a couple of weird features I haven't seen before and I'm curious if anyone knows what they are. First, the metal strip running from bridge pickup to bridge (that line is not painted, it's literally a piece of metal embedded in the body). And second the two small holes either side of the neck pickup. See the third photo for closeups.

Hello! I'm fixing up a second hand bass and the tone knob is not working. Can anyone help me find out whether it's a wiring issue or a faulty pot that needs replacing? I've taken some photos of the wiring, it looks correct to me but maybe I'm missing something. All the solder connections seem pretty solid. Thank you!