| Author | Message | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 221 Registered: 12-2008 |
Here is yet another Activator jack wiring question. I’m hoping the electronic savvy club members or Mica can help on this simple (except to me) question. I bought Slawie’s jazz bass activator set (JZ / AE-1) to install in my G&L JB-2 bass (Thanks Slawie!). All well and good until I realized the G&L uses a body (side-mounted) jack instead of the typical Fender pickguard-mounted jack, which is what the JZ / AE-1 uses. Oddly enough, my only Fender Jazz has a side-mounted jack as well. I can use the original jack if I mount it to the backplate, but would rather not. After searching through the club archives, I ordered a Switchcraft 152B jack but am still having difficulty figuring out the wiring. The 152B has connections for tip, ring and sleeve. Not being electronically sophisticated, the archived circuit diagrams didn’t really help. After doing continuity tests on the existing jack, I’ve figured out the red signal goes to the tip, the black signal (ground) to the sleeve, and the battery black (-) also to the sleeve. However, red battery (+) and red/white signal are still puzzling me. I can’t get a reading on these two as the plug insertion changes the configuration, as it is supposed to do for the battery on/off. So, my question is: where specifically do these two wires (red/white signal and battery red +) install: tip, ring or sleeve, respectively (assuming the 152B is actually the correct jack, of course)? Thanks for the help. Jon | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1618 Registered: 6-2002 |
The Red is the (+) from the battery to jack. The Red/White is the switched (when jack is inserted) (+) from the battery. So those two should never be connected to the tip or ring. The Black (-) goes to the sleeve. Purple is the hot signal and connects to the tip. There's no separate ring and tip connection. Only sleeve,tip, and the switching for the battery connection. (also assuming the jack you have looks like the stock one). elwood | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1619 Registered: 6-2002 |
I see the 152B doesn't have the extra connections for the battery switching. Is there a barrel jack that does? If not you will have to get a bit creative. | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 222 Registered: 12-2008 |
Thanks for the response. No purple wire in this setup. Only red and black for the battery connection and red, red/white, and black for the electronics. If there is a better jack for this purpose, I'll obtain it. Got this one after reviewing the club archives. Jon | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1620 Registered: 6-2002 |
I've seen a few shades (on different activators) of what I call purple, so I'm pretty sure your RED attached to the filter is the hot signal lead, and should be attached to the tip. I have a few G&L's, it would be great to find an easy retrofit barrel jack with the extra switch. I'll look around...maybe someone here knows of one. I guess one option, though not completely elegant,would be to add a mini toggle for the battery power(between the Red from battery and red/white going to filter). I wonder if there's a way to make it work using the inserted jack to close the (-)circuit between the ring and ground. I'm still a newbie at electronics(but have a few sets of activators lying around). Maybe Mica or others can help come up with something. | ||
| dfung60
Senior Member Username: dfung60 Post Number: 608 Registered: 5-2002 |
You have the right jack. You need a TRS/stereo phone jack to do the power switching trick. The way this power switching works is simple after somebody tells you and completely non-obvious until then. In a passive instrument, the + signal is connected to the tip conductor and the -/ground (it's the same thing) is connected to the sleeve connector. In an active instrument, you want to turn off the power to the preamp when you unplug the instrument. The TRS connector lets you do that with a little trick. It helps if you look at a TRS plug which you might have on old headphones, or you can see a mini-TRS plug on modern earbuds or headphones. When you use it "the way you're supposed to" , the tip is the L+ signal, the ring conductor carries the R+ signal, and the sleeve carries a common ground for the two channels. But if you stick a mono phone plug into this jack - like a guitar cable - the longer sleeve conductor on the plug will short the ring and sleeve contacts on the jack together. That turns out to be just what you want for the power trick. For active guitar electronics, the ground is the same as - audio and is also the electrical ground for the preamp. You still connect the audio output of the preamp to the tip conductor and the audio will come out fine. You connect the -V power supply (e.g., 9v battery -) to the common ground that you were using for audio. If you connect +V from the battery to the ring connector on your jack, then when you plug a mono guitar cable in, it will short together ring and sleeve, which completes the circuit for battery power, and your preamp magically turns on. The end result here is that you should connect the audio output + to the shortest pin on the jack, connect the battery + wire to the longer pin on the jack, and the common ground will connect to the strain relief. There should be wires for all these functions coming out of the active EQ module. Hope that helps, David Fung | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1621 Registered: 6-2002 |
I'm happy to see your input David. If I'm thinking wrong please let me know... ...wouldn't connecting the +V from the battery to the ring lug,with the -V from the battery on the sleeve lug, cause a short in the battery? Connecting the -V to the ring lug instead makes sense to me (and tying the red from the battery terminal with the red/white to the filter with a wire nut), but like I said I'm still quite a newbie. Thanks,elwood | ||
| dfung60
Senior Member Username: dfung60 Post Number: 609 Registered: 5-2002 |
Elwood - Yes, you're correct - you don't want to connect the battery terminals directly to the jack or you'll have a very hot battery very quickly when you plug in your guitar cord. Most preamps have a +V power wire relative to the preamp. You connect the +V terminal on the battery there, and the -V terminal on the battery to the common ground. When you insert the power plug and it shorts ring and sleeve, the power will flow, but it's not a dead short - the current will flow through the preamp IC which is what you want. But you really want -V on the sleeve along with the audio grounds. I took a quick look at EMG and Aguilar preamps that I have and they're like this. The preamp might also include both +V and -V connections as part of it's wire loom. So you connect both battery wires to the preamp module. Jon's description of the wires sounds like there's a lot of lines here. Is there an Activator wiring diagram on the site here somewhere? That would resolve the question. David Fung | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1622 Registered: 6-2002 |
Here's a pic of a stock set-up I found, that should make things easier to reference:  The red/white wire from the filter is the +V , I say that should be connected to red from the battery. The purple (in this photo) is the Audio (+), and should connect with the tip of the jack. The black wire from the battery terminal -V, connects to the ring of the jack. The black wire from the filter connects to the sleeve. I think that would do it. Am I missing anything?  | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 223 Registered: 12-2008 |
Elwood and David, my apologies. I took some photos of the setup (to follow) and what I saw in daylight and called red is actually purple in different light. From my continuity tests* and your various comments, I think the wires are as follows: Red battery (+) to ring Black battery (-) to sleeve* Black (preamp) ground to sleeve* Red/White (preamp) power to sleeve Purple (preamp) audio to tip* I confirmed the ones with the * using a TRS cable and multimeter. The difference to Elwood’s notes are battery connections to ring and sleeve. It seems to me the black battery (-) should be to the sleeve, per the existing setup. The red battery (+) to ring makes sense as it would link to the Red/White when the jack is inserted. Please let me know if you guys think this is correct. Here is a photo showing the various wires, jack and the preamp/filter/volume units: | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1623 Registered: 6-2002 |
With the existing setup, the (+)battery signal to the preamp is switched ; solid red from the terminal-->switched at the jack module(not connected to plug terminals though!)-->then to the red/white that feeds the preamp. Now with the TRS barrel jack, you'll be energizing the preamp by closing the battery (-) with jack ground. The mono jacks sleeve will bridge the battery negative (at the ring), with the preamp negative (at the sleeve). So you will want to wire nut the red battery wire with the red/white filter wire to keep the positive feed solid (since you are switching the negative). | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 224 Registered: 12-2008 |
Thanks. I think I understand what you've described, but let me check. I don't want to harm anything. Using the TRS barrel jack: Red (+) Battery joined directly to Red/White preamp (no direct connection to jack). Black (-) Battery to Ring Black preamp to Sleeve Purple preamp to Tip On-Off switching occurs through the mono plug making the Ring-Sleeve connection of the Battery (-) and Black preamp. Correct? (Apologies to those members for whom this is elementary) Jon | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1624 Registered: 6-2002 |
Sounds good...that's gonna be a cool JB-2 | ||
| dfung60
Senior Member Username: dfung60 Post Number: 610 Registered: 5-2002 |
Jon - Thanks for adding the pix. This makes sense now. The stock, plastic bodied jack with short threads has independent power switching terminals. Elwood's analysis is correct - the stock wiring is switching the +V side of the battery. You can confirm this by a continuity check. With no plug in the jack (mono or stereo), when you test red with red/white it should be an open connection. When you insert a plug into the jack, red and red/white should be shorted together. With the Switchcraft panel jack, you will directly connect the +V side and switch -V/ground on insertion. Your last callout at 9:39AM should work! If you haven't completed it already, you should be good to go. Good luck, David Fung | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 225 Registered: 12-2008 |
Many thanks to you both. I'm going to be working on it today. I really like the bass, but have outgrown the tone since going Alembic. Jon | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 226 Registered: 12-2008 |
G & Alembic JB-2  Body  Here is the finished product, stealth mode. Had to reverse the controls to fit the cavity, so the filter is toward the neck. Thanks again Elwood and David. Jon | ||
| elwoodblue
Senior Member Username: elwoodblue Post Number: 1625 Registered: 6-2002 |
Oh yeah !!! Well done Jon, thanks for the pics. | ||
| slawie
Senior Member Username: slawie Post Number: 794 Registered: 8-2002 |
I just got back from a weekend away to find this thread. Sorry Jon I was not around to help with the installation. I see though that it is all resolved. Great bunch of folks here! Kudos to you. Your bass looks very nice. Pretty much the same wood recipe as it's previous host - albeit Fender. How are you finding the sound? slawie | ||
| jon_jackson
Advanced Member Username: jon_jackson Post Number: 227 Registered: 12-2008 |
Much improved to my ears. Certainly a broader and brighter palate from which to work. This bass hasn't seen any activity since I discovered Alembic in 2009 but at least now it has a fighting chance. Jon |
