Installation of active pickups has failed

[sonikelectrik]

Hi guys

I have been trying to install active pickups in my sons guitar. Its a BC Rich and he wanted 'modern metal output' so he wanted active pickups, even though I advised him against it. i have no experience with this type of circuitry, and despite following the instructions (more or less) I have no sound at the amp.

I have one volume pot and Gibson style 3-way switch and a kill switch (that I have disabled for now as I troubleshoot the signal).

I have copper shielding inside the cavity with a master ground lug screwed into it and all grounds connect to the lug.

I have 2 wiring diagrams that show the kill switch circuit and the non kill switch circuit. Either way I have no sound. 

Here are some measurements I took with my multimeter on the 200K setting (sleeve/tip refer to a plugged in guitar cable):
- sleeve to kill sw -ve = -1.5
- sleeve to shielding = 1.7
- sleeve to battery -ve = -22.7
- sleeve to battery +ve = -23.7
- sleeve to switch ground lug = 1.7
- tip to switch in lug = 0 (continuity)
- tip switch common lug =  0 (continuity)
- tip to pot lug 1 =  0 (continuity)
- tip to pot lug 2 =  0 (continuity)
- sleeve to pot lug 3 =  0 (continuity)
- pot case to shielding  0 (continuity)

Make of that what you will. It seems like I have continuity in the correct places. 

One thing I could not test is if the pickups are operating properly. I tested resistance across the white (hot) and bare (ground) cables and got zero reading. But I don't know if that is to do with active pickups.

Any advice as always is greatly appreciated.
Cheers
Adam

*note: Illustration may show connections to output jack incorrectly. Diagram is for illustration purpose only. Wiring is correct - Tip (hot) Ring (power) Sleeve (ground)

Wiring Diagram with No Kill switch


Wiring Diagram with Kill Switch

 

[sonikelectrik]

Anybody? Anything?

[b4nj0]

I have no experience with active pickups but I have gleaned over the years that they generally tend to need a much lower value potentiometer, say 25K instead of 250K / 500K etc. Because you said that you're upgrading pickups I wondered whether you had replaced the pot(s) too?

e&oe ...

[newey]

It looks to me like you have grounded the common lug of the three-way switch and wired the lug used as a frame ground of the 3-way to the volume pot? 3-way switches do vary, and I can't be sure due to the stylized nature of the drawing of the switch, but typically the center lug of the 3-way is the common lug (i.e., the output) and the frame ground is at the back of the switch.

[sonikelectrik]

Mar 24, 2021 4:07:02 GMT -5 b4nj0 said:

I have no experience with active pickups but I have gleaned over the years that they generally tend to need a much lower value potentiometer, say 25K instead of 250K / 500K etc. Because you said that you're upgrading pickups I wondered whether you had replaced the pot(s) too?

e&oe ...

Yeah I just learned this too. We did replace the pot (original was terrible janky mini pots) but just used typical humbucker 500k pot. My understanding though is that it will have more impact on tone and roll off than affecting the signal when fully closed (full volume)

[sonikelectrik]

Mar 24, 2021 11:19:11 GMT -5 newey said:

It looks to me like you have grounded the common lug of the three-way switch and wired the lug used as a frame ground of the 3-way to the volume pot? 3-way switches do vary, and I can't be sure due to the stylized nature of the drawing of the switch, but typically the center lug of the 3-way is the common lug (i.e., the output) and the frame ground is at the back of the switch.

Im fairly certain the center lug is not the common out as it is not connected to the switch ins. The two blades at the back are switched from making contact with the input blades, so I’m pretty sure that would make them the output commons. I will get a photo so you can see better. 

[newey]

No need, you're looking at the part and I'm just looking at a diagram. As I said, these three-ways exist in varying configurations.

I, too, have no experience with active pickups. I don't know how you'd test to see if they were operating but I suspect that you'd need to have power to them for any testing.

[sonikelectrik]

So I’ve come down with some flu like lurgie so won’t be working on that this weekend. I did disconnect the switch and the pot - routing the pickup directly to the jack -with no improvement. 

I wonder if the jack is miswired. There are two wires: a red and a sheathed red surrounded by bare strands of ground. I’m wondering if, knowing now what you taught me about signal ground and power ground if I have the jack wired back to front. Active pickups don’t need a ground as they are internal shielded. So the red/bare pair are more likely to be the power delivery and ground, as opposed to signal hot and (unnecessary) ground. 

Does that sound more likely from a logic

[newey]

So the red/bare pair are more likely to be the power delivery and ground, as opposed to signal hot and (unnecessary) ground

An active pickup may not need a shield connection- again, I'm not familiar with them. But both the power circuit and the guitar circuit need a ground. In the case of the power, there will be a power connection from the pickup to the battery (I am assuming these pickups have an internal preamp, since you haven't mentioned an external one); the ground connection will typically go from the battery neg to the jack. And the jack will typically be a TRS ("tip-ring-sleeve", aka a "stereo jack"), with the battery negative wired to the ring connection so that power is disconnected when there is no cable plugged into the guitar, to save battery life.

On the signal side, there has to be a ground to complete the circuit. So my guess is that the single red wire would be the power wire to the battery + termial, and the shileded red wire would be the signal hot and ground.

But I see no reason to be speculating about this. What type of active pickups are these? Did they come with any wiring instructions? Even if they did not, a quick internet search should yield something, I would think.

[sonikelectrik]

Hi newey.

Yes, everything you say is as I understood it. I had it correct the first time.  I traced the tip to the red shielded wire, so that’s obviously the signal. And my initial assumption the single red was the power, although the instructions say this goes to the battery negative, wth the battery positive going to the pickups. 

These are GFS REDactives. I got a PDF in my email receipt with a wiring diagram with and without preamps. My understanding is the preamp kit gives additional EQ options, whereas the standard install ( what they call the solder install) connects everything directly without any preamp. I followed the latter. My understanding is that option gives cleaner, noise free signal over longer cable run, and possibly hotter output. There was no mention a preamp is necessary for the pickups to work, just a battery. 

I tried to connect the pickup to power power and measure resistance across the black and white terminals. At one point I got 18k on the meter but I could not replicate that result. 

I contacted their tech support but I’m still waiting to hear back. I’m hoping it’s defective pickups at this point as that would make the most sense. 

Thanks, I’ll keep updating 

[sonikelectrik]

Well here’s the latest. Turns out the 3-way connector on the back of most active pickups is specific, not surprisingly, regarding which way the wires connect. GFS in their infinite laziness don’t ship their pickups with instructions. Instead they send a link to a pdf with the receipt / invoice. On that pdf hidden away is little blurb about how to connect this. 

Apparently I missed this, connected the wires back to front and fried the pickup. $60 down the drain. So mad, not only at myself, but also at GFS for being so flippant when the outcome is catastrophic (for the pickup). You’d think a bit more diligence wouldn’t go amiss when it’s quite easy to destroy the thing you just bought and waited a week to arrive. 

Ill never do do business with GFS again, especially after several emails back and forth with their support who, again not surprisingly, take the attitude “oh well tough crap for you I guess”.

i knew I should have stayed with passive

[frets]

Hi Sonic,
I wanted you to know that I’ve been following the thread and I am so sorry this happened. The CEO of Guitar Fetish is Jay Abend. I’ll PM you his email address. If you contact him about what happened, I think they might replace them or give you your money back. It’s worth a try.😺

[sonikelectrik]

Thank you Girl-tech. I wanted to craft a letter to complain to someone higher up. If for no other reason than to provide better instructions in the box


i appreciate your help

adam

[thetragichero]

a used set of emgs can be had for about a hundred bucks on reverb. if you end up getting a refund that's the route I'd go. i have a guitar with a duncan blackout in the bridge and emg in the neck. sounds pretty good, although the duncan draws a ton more current than the emg (had two blackouts in there before and was curious why batteries were dying quicker than i had expected). i do like some of the passive gfs pickups but for active stuff i prefer to stick with standard name brand emg/blackouts