Sadowsky on-board pre, but replaced with a barrel jack - help

[Consul]

Hi all
After installing the pre in my new build, I took off the switchcraft jazz bass plate jack to replace it with a barrel jack that inserts in the side of the body. Initially my mistake was ordering a mono jack, so after much wasting of solering time, realised I needed a stereo barrel jack. Now I have one, I cannot get it to work. From what I've worked out the hot goes to the centre lug, the battery to the right lug (Looking at it from the middle lug at the bottom from above), and the final wore to the remaining lug. I htried soldering once, it didn't work, so rather than play trial and error with solder, I have been using alligator clips to connect ythe relevant preamp wiries to the barrel jack lugs. Doesn't seem to matter what I do, it's noisy and I can't get a noise from the pick ups. Any idea please? The Allparts barrel said it was sereo, and I tested it with a stereo jack and multi meter and it is reading tip, ring, sleeve, so I can't
t work it out. Any help please?

 

[ctmullins]

Since you have a meter, you know which lug is which.

Sleeve is ground.

Ring is battery negative wire (usually black).

Tip is preamp output.

 

[MidlifeBeginner]

When you plug in a mono cable, you should see that sleeve and ring get connected. That is what switches on the power to the preamp.

 

[Consul]

Since you have a meter, you know which lug is which.

Sleeve is ground.

Ring is battery negative wire (usually black).

Tip is preamp output.

Thanks for responding

When you plug in a mono cable, you should see that sleeve and ring get connected. That is what switches on the power to the preamp.

Unfortunately you can't see anything with a barrel jack - unlike a normal switchcraft where its all visible

 

[MidlifeBeginner]

Thanks for responding

Unfortunately you can't see anything with a barrel jack - unlike a normal switchcraft where its all visible

You won't see the connection, but you can measure continuity with your meter.

 

[Consul]

Since you have a meter, you know which lug is which.

Sleeve is ground.

Ring is battery negative wire (usually black).

Tip is preamp output.

Thanks for replying CT - This is why I'm going nuts - I have been connecting it (admittedly with alligator clip wires) as per the R, T, S config, but I just get a horrible hum and no noise from the bartolini's when I tap them with a magnetic screwdriver (Which I know works because I tested it on my Pedulla - the barts on it will pass a screwdriver through as a tap noise to the speaker) - and I have to do that because the neck is off and can't yet be re-attached without further work, so its the only method I have of testing if the pickups are delivering signal to the amp. Guess I'll keep trying, but eventually have to start pulling each of the 4 pots out and test them - its such a complicated pre though, with tiny boards on each pot as well as a little discreet board that you stick to the cavity - oh, and I bought it over a year ago from Italy, so no hope of a warranty if it turns out there is a problem with one of the circuits/pots, even though I haven't taken it out of the box until this month

 

[Consul]

Thanks for replying CT - This is why I'm going nuts - I have been connecting it (admittedly with alligator clip wires) as per the R, T, S config, but I just get a horrible hum and no noise from the bartolini's when I tap them with a magnetic screwdriver (Which I know works because I tested it on my Pedulla - the barts on it will pass a screwdriver through as a tap noise to the speaker) - and I have to do that because the neck is off and can't yet be re-attached without further work, so its the only method I have of testing if the pickups are delivering signal to the amp. Guess I'll keep trying, but eventually have to start pulling each of the 4 pots out and test them - its such a complicated pre though, with tiny boards on each pot as well as a little discreet board that you stick to the cavity

Also - here's a photo before I removed the neck to do a little tinkering - it's my first build (bought neck though)