Hi guys, I'm working on a 6 strings CBG, and I'd like to install both a piezo and magnetic pickup; I don't know if it's possible, the idea is to use a 3 way switch to blend the magnetic and piezo, using them separately when I need: basically, position 1 is the magnetic pickup by itself, position 2 could be both magnetic and piezo, position 3 the piezo by itself.
I'd like to send the piezo through an EQ preamp system I've got on eBay (you can see it in the picture below), but I'm not sure about how the wiring works.
Any suggestions?
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Hi guys! I'm still working on my CBG; I decided to make a few changes, adding 2 strings and 2 more pickups. So, now I have a 6 strings CBG with HSS pickups (standard Strat wiring with 5-way switch) and piezo. To see how it works, I made a diagram, that it's way easier to understand than my words. I have a doubt about it: I want to add the diode as The Phrygian Kid suggested, but I'm not sure where I have to solder it and how. Could you guys explain better? What do you think of my idea?
Here's the diagram
P.S. Obviously, I'll use a common ground.
First of all, thank you guys for your help and support.
I did a few tries, and I maybe understood how it works. I'm going to explain what happens:
1) I plugged the piezo in the EQ, then the EQ to the battery/jack module; clearly, the battery is inserted.
2) I've put the first probe to black wire that comes out from the battery, while I've touched the battery blob with the second one (placed right bottom).
The multimeter sounds, that means this two points are in continuity.
3) Keeping the first probe on the negative wire, I moved the second to the alleged ground blob (as David L suggested, placed left bottom); this time I got no sound.
4) Then, I've moved the probe to positive wire from the battery, while I've placed the second one on the positive blob (on top); as before no sound.
I repeated the last two steps, but this time I inserted a jack before to try. Surprisingly, I got sound from both (obviously positive to positive and negative to negative). So, it looks the system is switched on by plugging the jack; consequently, the second diagram David posted is the right one for me. Am I right?
Hi Matteo,
The information is really helpful. The second diagram would work but it was the plan if the first diagram didn't work. I think this is better
The blue wire is doing the connection that the jack does.
The red wire is the live to the 3 way and the black goes to the common ground point
The green cut on the black battery wire you extend the two cut halves and insert your switch.
Thank you David, your diagrams look really simple! To do a better job, instead of cutting the black wire I'll probably unsolder it from both the battery and the B- lug, to replace it with two longer wires, to insert the switch; correct me if I'm wrong, but turning off the switch stands for unplug the jack, isn't it? This way, the battery will not drains.
I was thinking of what you might find easiest to do ( ie simple soldering of wires to the existing blobs and adding the switch to existing wires) and also adding the switch where I know it will definitely turn the preamp off, but if you don't like to do that it is just as simple to totally ignore the black battery wire and add the switch to the blue wire so when on it will be like a jack plug is in place and when off it will be like the jack plug is pulled out. (So long as you are happy it is off with the jack plug removed).
I would do this rather than trying to solder new longer wires to the pcb.
Yes you're right. Basically it's the same, but your idea it's way better.
So, let me know if I understood: when using the magnetic pickup, I don't need to turn on this new switch I'm adding, while when I use both magnetic and piezo, or just the piezo as well, I have to turn on the switch, that it's like plugging the jack to the PCB.
It seems pretty easy; this image should explain better than words.
Yes the diagram is right and you fully understand how to use it.
Good luck with the project :o)
Ok guys, I've got some news; I've looked on the internet to understand how to check continuity, it looks easy enough. If I understood, I have to turn the multimeter ring nut to continuity mode, it is the one that it sounds when I put the tips in contact.
The thing it's not totally clear is where I have to place the tips to check continuity; I have an idea, but I want to be sure for everything to work. Anyway, I guess tomorrow I'll try if I can figure it out.
I almost forgot: I'm curious about what The Phrygian Kid said, about the diode and the master volume (the type of diode needed and how to wire the circuit).
In the meanwhile, I thank you guys for your precious help you gave me, without you it would be impossible for me to wire this circuit. If I get rich, I'll build you a statue, I promise you. :)
Hi Matteo,
If your amp is wired the same as this one it has a fault with the wiring such that the preamp is always on. If this is the case it will be much easier to add a switch.
Here you can see the four wires linking the EQ unit and the battery/jack module
From top to bottom
yellow B+ (positive battery connection)
whiteB- (negative battery which should be connected to one of the two jack socket sleeve lugs)
red OUT (live signal from the preamp going to the jack socket live lug which connects with the jack plug tip)
black GND (common ground which should connect to the other jack plug sleeve lugs)
So you can see better the 4 wire clip is removed and you can see a black wire from the battery (that I can trace going to the left of the white 4 point block to the lower right solder point for the jack socket) and a red + battery wire going to the yellow + of the 4 wire block via the circuit board (checked with multimeter).
The part we are interested in is the left hand side with the 1/4 inch jack connected ie the three left hand big blobs of solder.. Checking with my multi meter continuity function the signal live goes to the top blob. Theoretically the battery black wire connects to the right of the lower blobs and then the lower left blob should connect to the white battery - of the 4 wire block so then the jack plug acts as a switch between these two connections.
On this unit the two ground points are permanently connected (both of the lower two solder points, the black battery wire, the white B- wire and the black GND wire are all permanently connected with or without a jack. If I plug in a piezo rod to the EQ unit I can use test wires to an amp lead and without the plug inserted to the battery unit I can get a preamp signal using the top solder blob connected to the tip of the amp lead and either of the two lower blobs connected to the shaft of the amp lead jack plug. This means for this unit the EQ is always on even when not plugged into an amp (and also explains why I was getting a short battery life).
If yours is the same it will make adding a switch so much easier. (if you have two test leads you can quickly check by the above method ie plug in the piezo rod into the eq and connect to an amp using the two wires to connect the tip of the jack plug lead to the top blob of solder and the shaft of the jack plug to either of the two lower blobs. then tap and rub the piezo rod and listen for the sound transmitted through the amplifier).
This is (I think) how it should work
The black battery wire needs to be cut in half and add an extension wire to each to connect to the on/off switch and the power on/off is sorted.
To connect into the 3 way switch you solder a wire from the top blob of solder to the piezo connection on the 3 way and the ground is soldered to the common ground all the other grounding points are going to (back of the volume pot commonly).
You asked about switches any can be used such as a mini toggle switch (single pole single throw sp/st or single pole double throw sp/dt or a rocker type switch avoid any switch that is "momentary" as they don't latch and stay on)
some links but check on ebay for lowest prices
http://www.ebay.co.uk/itm/2-pcs-On-Off-2-TermInal-SPST-Black-Round-...
http://www.ebay.co.uk/itm/4Pcs-Blue-AC-125V-6A-3-Pin-SPDT-On-Off-On...
http://www.ebay.co.uk/itm/SPST-Chrome-Mini-Toggle-switch-6A-120vac-...
If when you check your module works correctly (ie no continuity between the two negative blobs of solder on the jack/battery module let me know and I will draw up the wiring you need for that to work.
Anything that is unclear please ask.
Regards,
David
Thank you David, my module is wired the same way as yours; the only difference is that I don't have any capacitor in the top right corner (as it shown in the photo).
I don't know if this could be an issue, I hope it's not, because the way you explained it looks pretty easy to do.
If it's not a problem, I'll try to check in these following days.
Regarding switches, I've found on eBay these two types. Are they good for my purpose? Which of them it's better?
Here are the links:
http://www.ebay.it/itm/5x-2-Pin-momentaneo-interruttore-pulsante-bo...
http://www.ebay.it/itm/4x-Interruttore-Bilanciere-LED-Blu-DC12V-Pla...
P.S. By the way, here's a picture I just took, to show you how my module looks.
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