Mastermind PBC not always passing wet signal

C

cwalk2113

Member
Hey everybody,

I've had an ongoing issue with my Mastermind PBC not always passing wet signal on my md-500, timeline, and big sky that's placed in that order at the end of my signal chain.

I'm currently running everything mono/parallel with exception of the md-500 which is mono/series to get the full wet signal from my mod effects, but my board is wired in stereo for whenever I finally stop being lazy and take my '65 deluxe reverb to church to get it put in the iso box.

Last Sunday, I tinkered a little bit with series/parallel just to see if it made a difference on the md-500 pre p&w service when it wasn't passing the wet signal on a patch that has a chorus effect and voila! I have chorus..... Switch back to series and nada, just dry signal. I've had the same issue with both the timeline and big sky as well, but never did a series/parallel "test" to see if that makes a difference. I honestly quite liked the chorus effect in parallel, but other effects like tremolo I prefer series.

Any help welcome with trying to fix the issue! Thanks everybody.
 
I have similar behavior and have played with this a bit too, so I’m watching this thread.

PBC 10
Loop 8 - TimeLine
Loop 9 - H9
Loop 10 - BigSky

By default, I run all in parallel.

I can put the TimeLine in series (great for swells), the H9 in series (great for modulation effects like trek or even chorus as long as I kill the dry signal in the PBC’s line mixer and use the H9’s dry signal instead), but when I put Loop 10 in series I lose reverb altogether. I guess I assumed it was just my lack of understanding of how the parallel chain works, though I think I get it, or that it’s something wrong with my cabling in loop 10 (maybe I’ll get around to checking that someday but it’s so rare that I want my reverb in series that it’s not a high priority for me).
 
Are you summing your stereo output to mono, by any chance? Stereo effects like chorus tend to disappear when you do that.

Please let me know exactly how your pedals are wired in loops 7-10 (cable types used, especially). That will help diagnose the problem.
 
rjmmusic said:
Are you summing your stereo output to mono, by any chance? Stereo effects like chorus tend to disappear when you do that.

Please let me know exactly how your pedals are wired in loops 7-10 (cable types used, especially). That will help diagnose the problem.
Click to expand...
Just using the left side, not summing down to mono post effects. I'll have to look at my stereo effects themselves to see if I did any summing either internally or by a switch of some sort on the back. It's been so long since I've messed with that stuff I don't remember what I initially did in setting up the board.
 
rjmmusic said:
Are you summing your stereo output to mono, by any chance? Stereo effects like chorus tend to disappear when you do that.

Please let me know exactly how your pedals are wired in loops 7-10 (cable types used, especially). That will help diagnose the problem.
Click to expand...
So I took a second this morning before pre service rundown and looked at my wet effects to see where the switches are set on the back. The md-500 doesn't have any manual switch on the back to do any summing, I'll have to look internally to see if that's an option that I possibly selected in my initial setup. The timeline is set to "stereo in/out", and big sky set to "cab filter off". One other issue I experience that I forgot to mention in the original post is when I try to bypass the md-500, timeline, or big sky they all stay in the signal chain although I have that loop on the PBC bypassed, still getting wet signal.
 
It sounds to me like your PBC is in need of repair. But, if we're lucky it's a simple one. One thing that can happen is that the lower board starts to disconnect from the upper board. If you open it up, there's a rigid connector that goes between the top and bottom circuit board. There are gold pins on one side that plug into the other side. If you can see more than a tiny bit of those pins (like more than a millimeter), then the connectors are not fully engaged. Simply pushing on the circuit board is often enough to reseat the connector and restore the connection.

You can tighten the screws, but be warned that, if this is a later model with rubber standoffs between the boards, overtightening will cause the standoff to twist into a spiral shape and it will actually get taller, disconnecting the boards again. Just tighten screws until they bottom out.

Here's a video that shows full disassembly of a PBC. You won't need all of this info, but in the reassembly part of the video, it talks about and shows that connector.

 
rjmmusic said:
It sounds to me like your PBC is in need of repair. But, if we're lucky it's a simple one. One thing that can happen is that the lower board starts to disconnect from the upper board. If you open it up, there's a rigid connector that goes between the top and bottom circuit board. There are gold pins on one side that plug into the other side. If you can see more than a tiny bit of those pins (like more than a millimeter), then the connectors are not fully engaged. Simply pushing on the circuit board is often enough to reseat the connector and restore the connection.

You can tighten the screws, but be warned that, if this is a later model with rubber standoffs between the boards, overtightening will cause the standoff to twist into a spiral shape and it will actually get taller, disconnecting the boards again. Just tighten screws until they bottom out.

Here's a video that shows full disassembly of a PBC. You won't need all of this info, but in the reassembly part of the video, it talks about and shows that connector.

Click to expand...
I'll give it a go and will report back with results. Thanks for the help!
 
Still haven't tested the PBC but I did open it up about an hour ago and wanted to report my findings..... I found that several of the coupler nuts (not sure if that's what they're called) between the 2 circuit boards had backed out which would cause the 2 boards to be spaced further apart. I gave them all a good hand tightening without the use of a socket (hopefully that's tight enough) to see if that fixes the issue. Should get to test the PBC later this evening.
 
There's a rigid connector between the two circuit boards. Make sure all of the gold pins are seated in the socket on the other side - if that disconnects, there will be problems with the loops in the bottom row.
 
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