TB-11 and Cool Rails Neck - output issues. Need help.

[JF]

Hi all -

Just finished my maple body soloist and got it all wired up.  Plugged it in and expected to hear sonic glory from the TB-11 bridge and Cool Rails neck. 

Not sure what happened - but the output was almost non existent. 

My soldering iron tip was pretty spent, so I suspected a bad solder joint somewhere.  Took it into a local shop and they touched up my grounding connections.  Output was better, but still very weak compared to my old JB/59 guitars.

Any suggestions what the issue could be?  Another weird thing I noticed is that the volume control basically turns the pickups off at a setting of 7.

At 10, they are audible but still seem very low.  Harmonics are non-existent and in Garage Band, my input signal strength is maybe at 15% with the mic set at full.

Pickup height is set about 1/4" from the strings, with the strings not depressed. 

Is there something else I need to look at - or is this combo that weak compared to a JB/59?

Could the volume pot be bad?  Anything I can troubleshoot with a meter?

Any advice would be helpful.  The guitar really resonates unplugged and plays awesomely - the sound is just not there...

Thanks!

 

[Jumble Jumble]

Sounds like you might have the two wires to the jack the wrong way round.

 

[Cagey]

Assuming it's wired right, since the shop should have flagged that right off, it sounds like your volume pot is not only the wrong value, but perhaps the wrong taper as well.

It's also possible that if you soldered any wires to the back of the pot body, you may have trashed the pot. They're not designed to dissipate that kind of heat. Modern pots use carbon-impregnated plastic resistive elements internally, and they're just not that robust.

Check the amount of resistance between the two outside lugs. Should be within 20% of either 250K or 500K. If not, toss it and put in a 500K audio taper pot.

If it is, disconnect the center lug and measure from the one side to the center lug. When the pot is at the midway point, it should measure something dramatically higher or lower than half of what you measured at the outside lugs. If it's roughly equal to half, it's a linear pot vs. audio. Toss it and put in a 500K audio taper pot.

 

[JF]

Well - I feel pretty stupid.  After paying the shop $18 to look at it and resolder the grounds, I noticed that the hot jack tab was making contact the shielding paint.  10 seconds with the dremel tool (and $3 for new solder gun tip) freed up the space and we are now ROCKING.  Don't think I'll be using that shop again in the future...

Should have predicting this when I was assembling.  The side jack hole was a VERY tight fit...Now everything sounds great! 

Although whatever the ground out was doing did give the guitar a weird/cool low output sound. :icon_scratch:

 

[Super Turbo Deluxe Custom]

Sounds like the paint had a really high ohm value. Rather than short the signal, it just introduced resistance in a parallel fashion.  The paint offers better coverage than the tape....because it's paint, but it's not without it's problems too. 

The one guitar (bass) I used the paint on, after every coat had dried, I ohmed it out.  With every coat, it dropped.  Initially in the 1000s, the lowest I got it was 4 ohms.  Then I just stopped.  In the future, I may do a grid of tape under the paint just to help with conductivity over the vast distance of the control cavity.

 

[Dan025]

Well - I feel pretty stupid.  After paying the shop $18 to look at it and resolder the grounds, I noticed that the hot jack tab was making contact the shielding paint.  10 seconds with the dremel tool (and $3 for new solder gun tip) freed up the space and we are now ROCKING.  Don't think I'll be using that shop again in the future...

Should have predicting this when I was assembling.  The side jack hole was a VERY tight fit...Now everything sounds great! 

Although whatever the ground out was doing did give the guitar a weird/cool low output sound. :icon_scratch:

when you short an inductor (pickup) with a resistor (the paint) you get a low pass filter. not to different than turning down the tone control but with greater losses.

 

[Super Turbo Deluxe Custom]

He shorted the hot to ground, except it wasn't a very good ground.  The shielding paint was in parallel with the guitar circuit.  Their resistances were split proportionately.  Had the shielding been better, the guitar would have had no output.