bought the k1083 preamp module from maplins yesterday and wired everything up exactly as showin in the manual, componants on in the correct polarity folowing print on circuitboard, connected it to my bass and it worked superb, unpluged everything, removed the two 9volt batterys, came back thismorning, plugged cables back in, put the (new) 9 volt batterys in but it does not work,
any suggestions on what to do as it is needed in less than 4 hours and i have now way of getting to an electronics store to buy a new one / get new parts…?
Very likely a mechanical problem, as electronic parts don’t go bad overnight. Check for loose wiring, bad solderings, damaged PCB, intermittend PCB tracks, loose sodering pads etc…
Ive tried de-soldering every componant and re-soldering them but still no avail, the tracks seem fine, is there anything i could do to get this kit working in the next few hours?
checked again, nothing is loose, tracks look fine, pads are fine soldering is fine.
when testing with my mp3 player and amplifier the output is EXTREMELY low i.e. 30 watt amp turned up full and mp3 player on full has about the same volume as position 2 on the volume controll when the pre-amp is not used,
i have found that bridging the right legs of R1 and R2 (legs closest to RV1) the output is only slightly lower than when the mp3 player is connected directly to the amp.
looked around the board, even used a magnifying glass, i cannot see any shorts,
please help as this is needed in less than a few hours!
If you are absolutely sure that a mechanical problem is not at the cause of troubles (which we doubt) then you should suspect a defective part.
However, as you’ve looked over it many times, maybe you’ve missed something. Have a friend to look at the circuit, maybe he will spot something you’ve missed.