ped Posted October 24, 2009 Share Posted October 24, 2009 Hi guys Excuse my lame diagram, but I am trying to work something out. I need to do a small bit or soldering to fit the internal Vbass kit into my bass, as shown here: Looks easy enough, but here is my current circuit - what's confusing is that both pickups and the earth boil down to a single cable which then goes to one of three nodes on the output jack. What should I do? If you could spell it out in laymen's terms, perhaps with a diagram, that would be helpful... Cheers ped Quote Link to comment Share on other sites More sharing options...
BOD2 Posted October 24, 2009 Share Posted October 24, 2009 Not quite sure what you're needing to do here. Is it just to attach a cable across the output of the bass before the output jack ? (not at all familiar with V-bass kit). Your jack has 3 contacts rather than two because it's an active bass and the third contact is used as a means of switching in the battery whenever a jack is inserted. The wire from the preamp to the jack will be the battery power, which connects to the battery when a jack is inserted. It's going to be messy but looking at your diagram of the jack with contacts at 6, 9 and 12 o-clock - I would say the white wire goes to the 6 o-clock contact (hot) and the black wire goes to the 9 o-clock contact (which is tricky because it already has three wires). What you could do is solder a small ring connector to a wire. Solder that wire to the 9 o-clock jack contact then solder all the wires that were there, plus the new one, to the ring. Cover the connector with insulating tape. Quote Link to comment Share on other sites More sharing options...
ped Posted October 24, 2009 Author Share Posted October 24, 2009 OK thanks for that - so I guess the white wire will effectively be attached to the 'bass signal' because it's the hot output to the jack from the vol control and the black wire will be soldered to the earth , but along with the bass signal wire at an earlier stage, too? Or should I solder it to the earth cable before the earth cable meets the pickup wires? ped Quote Link to comment Share on other sites More sharing options...
BOD2 Posted October 24, 2009 Share Posted October 24, 2009 Hmmm.... all the earths are "common" so it shouldn't actually make any difference at what point you attach the black wire. As long as it's a good earthe connection it shouldn't matter. What does this device do ? Does it take the output signal of the bass and the input it into a processor of some sort ? If that's the case then yes, the earth can be taken from anywhere. Quote Link to comment Share on other sites More sharing options...
ped Posted October 24, 2009 Author Share Posted October 24, 2009 The full schematic is here (though I am not installing the switch/buttons/led) [url="http://www.roland.co.uk/products/productdetails.aspx?p=966&tab=Downloads"]http://www.roland.co.uk/products/productde...p;tab=Downloads[/url] it's basically this (which I am currently using + loving) but in kit form for internal installation: [url="http://www.rolandus.com/products/productdetails.php?ProductId=648"]http://www.rolandus.com/products/productde...p?ProductId=648[/url] Basically the Vbass kit works separately from the usual pickup and output but needs to tap into the standard electronics for bypass mode or to blend in the magnetic pickups. Does that help? I might give it a go and see... One more question, will trimming the edges from this PCB have any effect on the unit? Quote Link to comment Share on other sites More sharing options...
ped Posted October 24, 2009 Author Share Posted October 24, 2009 Update - all soldered up and working! great! Now I need to do the woodworking part which should be easy. Cheers ped Quote Link to comment Share on other sites More sharing options...
BOD2 Posted October 24, 2009 Share Posted October 24, 2009 Fast worker ! Provided there is nothing attached to either side of the edges of that PCB, it should be ok to trim it. Excess copper is sometimes used as a heatsink on PCBs but there has to be something soldered to it for this to work. You'd need to be careful not to stress the wires or flex the PCB while trimming it though. Quote Link to comment Share on other sites More sharing options...
ped Posted October 24, 2009 Author Share Posted October 24, 2009 I think I can get around that now, so no need to trim. Space is at a bit of a premium in my control cavity so it might have been useful, but I think I JUST about have enough room. Quote Link to comment Share on other sites More sharing options...
ped Posted October 24, 2009 Author Share Posted October 24, 2009 Aw man I could get this finished tonight but my drill isn't charged up... typical. Ah well, something to do tomorrow I guess... Another quick question - when I mount the jack and GK output plates, should I drill small pilot holes for the mounting plate screws, or drive them straight into the wood? ped Quote Link to comment Share on other sites More sharing options...
ped Posted October 24, 2009 Author Share Posted October 24, 2009 OK, I had enough juice in the drill to make the mount for the standard jack, and have started boring through for the 13 pin output, too. I have replaced the old jack (on the front of the body) with the GK assignable knob instead, and wired that in, too. All I have to do now is finish the second hole for the GK output and drill a hole for the GK pickup lead into the control cavity.... Cheers ped Quote Link to comment Share on other sites More sharing options...
Kiwi Posted October 25, 2009 Share Posted October 25, 2009 that looks pretty technical Quote Link to comment Share on other sites More sharing options...
elros Posted October 25, 2009 Share Posted October 25, 2009 Sorry I'm late for the party. You've got it right, obviously, but there's one little detail: since your bass circuit is active and switched by the output jack, it won't be on if you use only the GK cable. For you it isn't a big problem, because as far as I can tell from your schematic you've got a passive mode. On my installation I made a little circuit that switches on the active electronics when power arrives from the GK cable. Quote Link to comment Share on other sites More sharing options...
ped Posted October 25, 2009 Author Share Posted October 25, 2009 Hi guys, Finished the install today - here are some finished pics. I will update my 'bas porn' thread later with some better ones. At the moment there are two or three screw around the new jack plates which haven't been driven all the way home because my screwdrivers are crap and I want to get some better ones later today. I am really happy that it all works superbly - considering I did it all with a crap drill, some bits, a chisel and a wooden mallet, I think it went quite well!!! Cheers ped Quote Link to comment Share on other sites More sharing options...
ped Posted October 25, 2009 Author Share Posted October 25, 2009 ...and yeah one of the screws holding the GK output is at an angle - when I was chipping away the cavity I took away a little too much wood in that corner, so there we go - holds very tight now, though. Quote Link to comment Share on other sites More sharing options...
ped Posted November 3, 2009 Author Share Posted November 3, 2009 One quick question OK here is the situation. Everything works. Just fine. However, the active circuit only works if a put a jack into the a/4" socket (even if I'm using the 13 pin output for the actual signal) because it completes the circuit like any normal active system. I have wired the jack holder part of the socket to the inside of the metal coated cavity (that's the bottom right wire in my diagram, the top of the two labelled 'earthed'), making the active circuit always connected, so it's there when I want it, but this drains the battery. How can I avoid this and make the active circuit switch on or off without having to use a 'dummy' jack socket? Will I need another switch instead? ped Quote Link to comment Share on other sites More sharing options...
elros Posted November 3, 2009 Share Posted November 3, 2009 Hi, Yes that's how it is these days. For some reason the guitar version of the GK pickup electronics has a built-in function for switching on the on-board electronics when the GK cable is connected, but the bass version has no such thing. Go figure. Anyway it is possible to build such a circuit on a DIY basis. All you need is a transistor (PNP bipolar IIRC) and a resistor (Rb anywhere from about 4k7 to 100k). I think I had a schematic somewhere... Until I find it, a dummy jack is a good solution. Quote Link to comment Share on other sites More sharing options...
elros Posted November 3, 2009 Share Posted November 3, 2009 Got it. Brief description: The jack connects the negative lead from the battery to ground, thus competing the avtice circuit. The transistor does the same thing when it recieves the -7V from the GK circuit. So you can leave the 13-pin plugged in, and just turn off the GK unit it is plugged into. This will deactivate the on-board electonics - provided there's no jack plugged in. Makes sense? Quote Link to comment Share on other sites More sharing options...
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