PBH-4 ( low output )

G'day wise ones,

I have straightened up the factory wiring of my PBH-4 kit to match the supplied diagram and the output is very low and I suspect this has to do with the grounding of the terminal on the volume pots.

I have looked through the forum for answers and also at a few sites and they all seem to have the same wiring format with the tag earthed but having said that other sites I have looked at all have a single volume pot.

Depending on where each of the pots is sitting this provides varying levels of signal shunt across the pups.

Your thoughts please because to me it just doesn't make sense to strangle the pups.

I am going to remove the earth from the three pots to see what happens and expect to find a massive jump in output.

BTW the pups in question are GFS not the standard kit pups but this shouldn't really be an issue.

Well, lifting the earth made 2 tenths of FA difference so it's back to the drawing board.

20W amp with all knobs at 11 and it would put a baby to sleep

Hi Dave, thats strange why the output is low. I haven't played my PBH for ages but don't remember it having a lower output.
Could it be possibly a dodge volume pot ?
Sure there are many configurations for 3 volume, 1 tone circuit. Maybe one of the wiring gurus can help.
I don't see the point of 3 volumes, so may be able to alter that to 2 volume, 2 tone

I would check the pups with multimeter and also check the pots.
Had a similar experience with GFS pups, not really very good quality but GFS are good at customer service.

About to say the same thing as DB. Check with MM if that seems fine jump the wires to the jack and see if you get high output there.

good idea DB and Nicko.
Dave also compare the resistance of the GFS pups compared to the PBG ones supplied with the kit

Thanks for the suggestion guys, I'll check the various impedences and get back.

It does seem odd though that when the coil tapped HB is taken into consideration what is effectively 3 pups and 3 vol controls all have the same behaviour and when mixed rather than 1 at a time the results are bizarre.

I have played the MM bass with similar mixing and it behaved as expected with just the tone changing with the blend rather than the volume.

I'll also run each of the pups / pup segments direct to the amp including pairing them and see what happens.

I'm out of time now until this evening but I will report back

sounds good Dave.
I had a similar problem with a HSH strat, with coil split humbuckers. The output of position 2 and 4 (when a humbucker and middle were paired) the output was lower.
It's also possible the humbucker is out of phase with the single coil neck pups so it may solve the problem if you reverse the wiring on the neck pups

Here's the tale of the tape ( ohm meter )

Kit pups
PB Neck - 8.71K
HB Bridge - 14.77 K ( Bk - W 7.32K & R - Gn 7.44K )

GFS pups
PB Pro sweet Alnico - 9.93K [ 11K in the catalogue ]
HB MM Pro Plus - 8.1K ( Bk - W 4.04K & R - Gn 4.05 ) [ 8.35 in catalogue ]

So the pups are within advertised spec and Pabs has used the MM Pro bridge pup in conjunction with the kit PB Bridge pup so should be OK.

Because the output problem is consistent across all pup combinations and also giving bizarre results as pots are wound up and down I think it will be a single item at fault maybe the cap, as the kit had a cap on each of the back two pots and one had a broken leg at the body of the cap.

More investigation to follow post a glass of medicinal shiraz :-)

What are your pot values, may be worth a check to see if something is amiss. Perhaps even post some pics of the wiring in case we can spot something.

It would appear that the pups need to be much closer to the strings than I have previously experienced ( 2.8mm is the PBass standard apparently )

The Sth pole of the HB is still not playing fair so a bit more investigation is required, I'm seeing the correct impedance and also seeing it change as expected through it's vol pot so somethings not quite right but it's now getting closer to the stage where I start setting the neck and bridge properly

nice one Dave so the output of the neck pup is pretty normal now ?
So is the humbucker being split by a push pull pot ? Sounds like there could be a problem with the pot or double check none of the solder joins are touching anything nearby the lugs

Quote:

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Originally Posted by wokkaboy

nice one Dave so the output of the neck pup is pretty normal now ?
So is the humbucker being split by a push pull pot ? Sounds like there could be a problem with the pot or double check none of the solder joins are touching anything nearby the lugs

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I wish it was that simple, both poles have individual vol pots and when the impedance is measured at the pots and the output jack I get the expected results with the relevant pots moving through their range and I know I am seeing the individual poles because they have 0.02 of an ohm between them. ( decent meter and quite a few years playing with electricity )

1. Turn the PB pup vol up and down and get the expected result.
2. Turn the Nth pole of the HB up and and down and get the expected result.
3. Turn the Sth pole of the HB up and get nothing
4. Bound PBass pup and Nth pole up and tone but not vol changes
5. Add Sth pole of HB pup and nothing changes

Very odd but we will get there in the end