The John East preamp club

[kazamamaster]

J retro deluxe 01 user here. Anyone Know offhand how to modify the pickup input gain?

 

[ctmullins]

J retro deluxe 01 user here. Anyone Know offhand how to modify the pickup input gain?

https://www.east-uk.com/wp-content/uploads/2025/05/J-RETRO-01-Deluxe-Op-Man-2024-11-20.pdf

 

[bassvirtuoso]

While I know I should email John about this issue, I figured I would try here first in case anyone had already run into this issue:

My bass currently has an East Uni-Pre in it. A handful of months ago when I last played it, everything worked perfectly; then it sat in its case for months. Fast forward to me playing it again recently and suddenly the active mode didn't work, but passive mode worked just fine. So I threw in a brand new Duracell, still nothing. Okay, so then I took it to my local tech who does amp work and amazing active wiring jobs for me (he installed the pre originally) - he looked at it for a week and couldn't find a single issue: battery is fresh, battery box is supplying power properly, he checked all wires that were screwed in, no luck.

So I finally get it back home, disappointed and plug it in: still works perfectly in passive mode, but I realize it has a very low output in active mode if I max out all controls and my pre gain on my amp (way louder than you'd want on any other bass) - so it technically works, but barely there active output.

Yes, I've checked the two red jumpers on the treble board per John's site as well, they look to be there and in place.

Any suggestions?

If anyone in the future reads this with the same issue, the battery lead into the main board was not screwed in fully, which lead to me getting a tiny bit of output in active mode but not full output. I pulled the wire and reseated it properly and all is well again. I'm never using that tech again.