B-Band Sys550 schematic?

[jlklein]

Hi folks,
I've posted before about my Alvarez AD60ce that has the B-Band SYS550 pickup system in it. Originally it had very low, hissy output that was recently completely fixed after I replaced the UST for about $20.

My current issue is a ground buzz that developed prior to replacing the UST that still persists (and is not due to having the UST cable reversed). It's not terrible, can't hear while playing, but it's noticeable enough when not playing to be annoying. It goes away completely if I touch the metal shell of the 1/4" cable when using a standard guitar cable, or if I touch the metal 1/4" jack itself if I'm using the XLR jack. Kind of like when your electric's bridge grounding wire breaks, but obviously that's not the case here

Does anyone know where I can get a schematic of this circuit to continue troubleshooting as B-Band is out of business now? St Louis Music (Alvarez parts supplier where I bought the UST) didn't know of one and I haven't had much luck Googling any. I need to determine if it's in the XLR/TS combo jack (some caps and resistors in there) or the preamp unit itself.

Thanks,
Jeff

[Melt in the Sun]

Possibly an idea out of left field, but I've had such a hum (including silencing it by touching the jack) be caused by a cheap stompbox power supply.

[jlklein]

Originally Posted by Melt in the Sun

Possibly an idea out of left field, but I've had such a hum (including silencing it by touching the jack) be caused by a cheap stompbox power supply.

Already ruled out. I bypassed my pedals (Mozaic+TC Natural+Jamman) and plugged straight into my Soundcraft mixer (with 3-prong power cable) using both the XLR jack and the 1/4" jack, same buzz. Plus, this is the only guitar out of four 6 and 12 string acoustic guitars that does it through the same pedals. All have stock pickups except one Ibanez that I installed a Fishman Presys in.

Thanks,
Jeff

[BT55]

It looks like you’ve ruled out the obvious problems. I would put a mirror in the guitar and look at the wiring. Even better, remove a few strings and wiggle the wires listening for any noise.

[jlklein]

So I still haven't found the issue, no luck with wiggling wires and no schematic available. I looked into getting a replacement input jack assembly but they're over $40. I was wondering if any of the other B-Band models such as the T65, which appears to have the same input jack assembly (XLR+TRS) would work? There are entire systems of those on eBay for about $60, so if the jack end is the issue great, but if it's the preamp, that would give me a replacement for that as well.

Thanks,
Jeff