PPCB Stumble Boost (JHS Notadumble / A Box Later)

apierz

Active member
Build Rating
5.00 star(s)
I Love Dead & Company and among Mayer fans few pedals have been subject to as much speculation as his JHS Box It Later. Pretty much anything else he has put on his board has been ID'ed and is clonable/obtainable (if at an inflated price) but a Dumble circuit that had never been officially confirmed had remained a mystery until recently. I was super stoked to get this PCB and slightly less stoked to discover its not much more than an op-amp boost with an effects loop.

On its own: Without anything in the loop, its a fine enough boost. Unlike the Fumble boost, I didn't notice a change in feel or sound between the two knobs. This isn't too surprising since they are just sitting on opposite ends of the effects loop with one controlling how much of the first op-amp gain stage makes in into the loop and the other how much of the signal goes to the second, bigger op-amp stage. JHS says the input should have an effect on impedance, and thus some changes to the tone in addition to volume, but it wasn't noticeable to my ear. One is a B2K and one an A100K so I guess you have some finer grain control with one over the other.

With an overdrive in the loop: One of the ways Mayer is speculated to use his A Box Later is to have one of his TS10s in the effects loop to get a different sound. I tried it with an 808 clone, but putting it in the effects loop wasn't doing anything noticeably different than just using the gain and volume knobs on the 808. I suppose if max gain and max volume on an overdrive isn't enough for you, this can raise the ceiling for both.

Modulation/Time effects in the loop: probably more useful to more people would be to use it as an effects loop with effects that don't have their own volume controls. I tried it with a chorus pedal and a reverb and it can definitely get those effects to whatever volume you need. That isn't something I need, but I can see it being useful to someone who wants to turn on a bunch of effects at once and/or adjust their volume quickly.

Build:

Five stars for the PCB, one star for my build. I ordered my enclosure from Tayda right away and used the original build docs to make my drill template. That version had the side jack holes in the wrong place and, never having done a side jack enclosure before, I didn't notice something was off until it arrived. I had to do some very ugly things to get it boxed up with the send and receive jacks. I included a gut shot, but I am not proud of it. The current version of the build docs looks like they have corrected the error.

There are boosts I like better, but the build isn't too difficult, the parts aren't hard to find, and an effects loop with volume controls on either side might be something you need.

Image.jpeg
 

Attachments

  • Image-1.jpeg
    Image-1.jpeg
    244.6 KB · Views: 23
Way to persevere and see it to completion. At first I was going to comment that Lumberg jacks are much more suited for this type of (side) jack orientation but I now see it's the rare PPCB board with jack footprints and they're actually shunting/switching jacks. Yikes.
I would have found the nearest body over water and thrown it as far as I could🤣
Way to go.
 
Modulation/Time effects in the loop: probably more useful to more people would be to use it as an effects loop with effects that don't have their own volume controls. I tried it with a chorus pedal and a reverb and it can definitely get those effects to whatever volume you need. That isn't something I need, but I can see it being useful to someone who wants to turn on a bunch of effects at once and/or adjust their volume quickly.
This is the reason i tried this build.. the input level makes it so i can throw a univibe in there and treat it somewhat like a normal pedal lol.. my les paul knocks the hell out of it so it clips a lot when played clean on its own.. the stumble makes that not happen.
I didn't notice something was off until it arrived. I had to do some very ugly things to get it boxed up with the send and receive jacks. I included a gut shot, but I am not proud of it. The current version of the build docs looks like they have corrected the error.
being an early adopter is fun, is it not? I ended up doing my own drill and paint so i missed that pitfall but it was still a tense moment at the drill press because i wasn't trusting my measurements.. it ended up being ok though.
There are boosts I like better, but the build isn't too difficult, the parts aren't hard to find, and an effects loop with volume controls on either side might be something you need.
I just built a transcendence boost a couple days ago. 10/10.. For those that can hear, let them hear indeed!
My one quibble with this stumble boost is that it doesn't actually have a super amount of gain compared to other clean boosts (esp something like the transcendence).. ...but it does stay clean all the way and the loop is functionally useful, so there's that.
 
Last edited:
Back
Top