|
Post by long813 on Sept 5, 2012 22:51:22 GMT -5
Howdy GN2! I've come to post a build - er, mod thread. A little background to the gem. It was my second electric guitar, purchased about 10 years ago for 500 or something. It worked well for what I was doing, but as years passed, I turned to hate the sound of it. Good thing this was an easy solution though - I was recommend by my guitar prof to look into SD JB's, which following that advice, made the guitar sound much better. It's been modded to hell over those 10 years, but only recently after coming back from college, I've taken the care to reinvent it ... also, in these last 10 years all the electronics minus the HB's and vol pot seem to have vanished. Over the last month I've been designing to schematics for this thing, but as I searched more, I learned more and eventually came here to JohnH's Modified JPLP scheme, seen here: guitarnuts2.proboards.com/index.cgi?action=display&board=nutzoid&thread=3772&page=2#48281It was everything I was scheming, plus more - the local switching and coil-split hum cancelling was something I could never have thought of. The order just went through on GuitarElectronics.com, and I must say that I hate the fact that I overpaid on so many parts (capacitors, 3way, jack), but with S&H to Canada, its impossible to justify a 20$ digikey order. In addition to the JohnH JPLP scheme, new parts: Bourns 500K P/P (same price as alpha, why not?) Switchcraft 3Way switch Switchcraft mono Jack Black Speed knobs (blakc metal would have been nice, but at 5$ each?) SD SH-2 Jazz Neck Time for pictures: Model: Epiphone Gothic Gutted, cleaned fretboard with Napatha, getting 0000 wool tomorrow as it is still mucky An attempt at a younger me trying to pull out the brushings. If I really cared, I'de switch them out too, but it's not worth the cost to me. A born again virgin control cavity! If it ain't broke, don't fix it. The stock tuners, work fine, so why bother buying new ones? SD JB Bridge, Stock Neck and Tune-o-matic bridge (also stock) And....the sexy beast that will be doing all the hot work Once the parts arrive I'll come back and give a play by play... and I hope it's quick.
|
|
|
Post by JohnH on Sept 6, 2012 15:37:59 GMT -5
Its going to be great, but I see one watchit:
The wiring is based on taking two similar HBs, with seymour duncan colours, and modifying one so that when you select both screw coils, the hum is cancelled. I did that for the case of covered Hbs, where the screw coils sound clearer IMO. You have uncovered, so it can be easier. But they are also from different suppliers, so we cant assume that polarities and phase will match properly.
Its always possible to sort this out, but it will involve a series of tests on the pickups to work out the best connections to make. I'm happy to help step through this if needed. Do they both have 4 conductor wiring? We'll need a new thread in the wiring section though.
John
|
|
|
Post by long813 on Sept 6, 2012 16:54:18 GMT -5
Its going to be great, but I see one watchit: The wiring is based on taking two similar HBs, with seymour duncan colours, and modifying one so that when you select both screw coils, the hum is cancelled. I did that for the case of covered Hbs, where the screw coils sound clearer IMO. You have uncovered, so it can be easier. But they are also from different suppliers, so we cant assume that polarities and phase will match properly. Its always possible to sort this out, but it will involve a series of tests on the pickups to work out the best connections to make. I'm happy to help step through this if needed. Do they both have 4 conductor wiring? We'll need a new thread in the wiring section though. John Thanks for the read JohnH! I may have missed a point, but I'm actually replacing the stock epi neck HB with a SD Jazz. Neck: SH2 Bridge: SH4 So, they are both from SD where the slug is North. - Future problem: I've seen that the switchcraft switch I bought will require a deep thread nut in order to mount correctly into the cavity. I will be going to Home Depot tomorrow to see if they have any and also buy some 0000 wool.
|
|
|
Post by long813 on Sept 7, 2012 20:14:02 GMT -5
Good news everyone! Order is now in the mail, glad it got out before the weekend.
|
|
|
Post by long813 on Sept 17, 2012 20:07:46 GMT -5
Order finally came in, woot woot! All is here, but I am a little disappointed that the cavity control plates didn't come with any screws. I'll have to go to the Home Depot I guess and find some. Parts: I'm also sadden by the fact that I paid 2$ for a treble/bridge STICKER! It's not hard plastic like the ones you usually get...Sigh. Below is a picture of my desk...very messy (temporary living, my computer desk is my workbench) so I can't get anything done yet! Drawer: ...I can't wait until I have a permanent residence. Also, I dreaded the day that this would come ... finding the 220k resistors. I have a load of resistors, but they are not organized at all (the moving..oh the moving) so this will be fun. I found a cool way to organize all my bits and pieces though! Get a binder, some baseball card sheets and 3.5x5" ziploc bags. Each sheet will hold 9 different components and you can label each bag for easy reading! Bag O' Fun... I'm going to organize all these tonight...hoooray. Btw, a colour blind man organizing resistors is a death wish.
|
|
|
Post by long813 on Sept 18, 2012 19:01:13 GMT -5
Update: Resistors are sorted for the most part, no 220K so I'll have to make some. Pots are for USA guitars, so I'm currently boring the last hole so they all fit. Neck is straight Next: Make the 220K resistors Print off schematics Sand neck down more (pictures to come of that, went a little to deep at one point, so I'm going to make it all even) Because updates without pictures are boring. The neck is almost done, was out for about 2 hours on it. Tiring and also dark out. It's sanded just so there is some paint left on the wood. I'm leaving it on there so I don't have to keep touching it up with gunstock oil or something. This is will be cleaned up tomorrow. The jig is up! Or, down... I guess? EDIT 2: So, I just paid 7$ on a pack of 150 resistors to just get two 220ks. Eh, on one hand, really? On the other, I know have a more complete resistor bank for future projects!
|
|
|
Post by long813 on Sept 20, 2012 23:30:22 GMT -5
9 hours later and the wiring is complete! I can't believe I spent 12 hours straight doing this. I didn't think it would be tough at all, but alas, working in tight quarters always presents issues. A set up is still required, but that is a tomorrow job.
Pictures will come tomorrow. I need sleep.
Some notes: -It was not easy working in this tight space. The harness was easy enough to make, but it became difficult when I had to hook up the toggle switch and pickups
-Nothing can ever be easy. The toggle switch needed some modifying to fit in properly, the output jack was too big (imperial size I guess) so I had to route some material out of the panel.
- The cavity cover I ordered does fit. At all. It was supposed to be a Epiphone cover, but it must be built for a Gibson. At the moment I have some tape over the cavity until I route it to fit.
-Biggest problem: Seymour Duncan seemed to have slacked off on my neck pickup. The wire was too short to be able to hook the pickup up to the harness out of the cavity. It was the same length as the JB I have (bridge) which is the obvious issue as the neck has more length to travel. I extended the wire - it's less than ideal, but it needed to be done.
-I tested this out for all of 2 minutes to make sure everything works. It does. But some issues arise. --Pots are scratchy --Buzzing when I don't touch the guitar (All I can see is that the bridge ground may not be hooked up properly as that's the only connection I didn't test)
Off to bed!
|
|
bowyn
Meter Reader 1st Class
That boy ain't right...
Posts: 85
Likes: 0
|
Post by bowyn on Sept 21, 2012 9:18:03 GMT -5
"Nothing can ever be easy."
Truer words have rarely been spoken.
I'm digging your progress.
|
|
|
Post by long813 on Sept 21, 2012 12:15:33 GMT -5
"Nothing can ever be easy." Truer words have rarely been spoken. I'm digging your progress. It's so true. Even the simplest circuit can never go right on the first attempt. Some updates, more problems: -The tailpiece is grounded properly, so the 'ungrounded hum' is confusing me -The Neck pickup vole doesnt work. In Neck position there is no sound. In middle position, the neck volume doesn't work, but the neck tone knob works and does have an effect (weird right?) -The taper of the volume pots is petty bad...for the bridge of course. It basically goes from 0 to 8, rendering the first half turn useless. Pictures to come after I tinker some more. EDIT: I see I forgot to solder the neck switch to the lug on the NV. It's connected, but not soldered. I tested each PU for grounding issues, but alas, connectivity btwn them and any ground. EDIT2: Soldering that up didn't do anything. Also there seem to be more buzz when in the neck pickup - and it doesn't work...
|
|
|
Post by long813 on Sept 21, 2012 14:09:35 GMT -5
Some pictures. I may have to ask for some help to any followers soon if I can't diagnose this issue! The toggle is extremely tight in there, the hot leads had to be bent sideways to accommodate the room *blurrycam 2.0 The harness is complete. Now for the easy part! ... oh wait, no, the easy part is complete...rrrr. Close up of the tight space My diagram of JohnH's-mod-of-Bosnova's-(sp?)-Twenty-Dual-Modified-Jimmy-Page-Les-Paul-Mod ...Damn that's a mouth full...TWSS. Schematic is on the back as well, as I took some time to relate the two and understand as much as I can. Starting to hook up the pickups to the harness. At this point I took about 30 minutes to logic out how I should hook them up as to minimize the clutter when inside the cavity. If you look on, you can see I chose wrong. Another view, The pickup selector was easy. I used 20 inches of wire for the hot (white) and 19 inches for the ground and pickups. This was one aspect I thought out right! A close up. As you can see here, I had to extend the neck pickup wires for reasons stated above in a previous post. Also, I must say that SD has downgraded their wires IMO. The jazz (new) is using that hard plastic insulation where as the JB (8 years old?) has the typical softer, more malleable insulation. Because the cover didn't fit... So, figuring out the problem on the mysterious neck pup is going to take A LOT of time. Neck pickup problem...I really hope it is not in the actual wiring add on I made b/c that is going to be hard to really diagnose (it's shrink wrapped and all). It is where I'm going next though if I don't see any other problem. To do/to fix:-Neck PU not working -Humm/Buzz -Volume taper is terrible -Set up (intonation, action, neck relief) -Scratchy Pots -Mod cavity cover to fit cavity
|
|
bowyn
Meter Reader 1st Class
That boy ain't right...
Posts: 85
Likes: 0
|
Post by bowyn on Sept 21, 2012 14:46:14 GMT -5
Ha! Wish I could help some, but I go cross-eyed looking at my own wiring! 4 push/pull pots? That's a lot of little connections, I don't envy you the tracking job to find the connection issue on that neck pickup. It's a ballsy setup, though, that's for sure.
If you're like me, undoing what you've spent so many hours doing is a horrific thought, but you might want to connect your neck pickup directly to the Volume pot, not using the switch part of it, and, if it works, try going backwards from there (ie, Just volume, volume + switch, tone + (volume + switch), then the full monty). That might also solve your buzzing issue in the process.
I suck at using a multi-meter, but if you're handy with one, you might also try testing it connection by connection without having to undo your work (except for the problem connection, that is).
|
|
|
Post by long813 on Sept 21, 2012 14:50:24 GMT -5
Ha! Wish I could help some, but I go cross-eyed looking at my own wiring! 4 push/pull pots? That's a lot of little connections, I don't envy you the tracking job to find the connection issue on that neck pickup. It's a ballsy setup, though, that's for sure. If you're like me, undoing what you've spent so many hours doing is a horrific thought, but you might want to connect your neck pickup directly to the Volume pot, not using the switch part of it, and, if it works, try going backwards from there (ie, Just volume, volume + switch, tone + (volume + switch), then the full monty). That might also solve your buzzing issue in the process. I suck at using a multi-meter, but if you're handy with one, you might also try testing it connection by connection without having to undo your work (except for the problem connection, that is). Yup! The 4 P/P pots only become harder and harder to work with as more wiring got involved. I was not expecting that it would exponentially become harder to wire - more planning could have definitely helped. Unsoldering and testing it going to be the last means. If I can find the issue with my DMM I'd be happy. Yet, if nothing comes up, I'll have to unsolder the mess and go from there. I just really hope I don't have to resort to that as it'll make my loose the rest of my hair! I must say, I love the feel of the neck w/o that terrible sticky paint! It's so smooth. I'm giving a play by play in hopes it helps fix the problem. First thing I checked was the pots to make sure that they weren't dead from overheating or something. Potentiometer Resistance:NV.R = 15.7 k NT.R = 463 k BV.R = 15.7 k BT.R = 473 k Foul play has been spotted. 500k // 220k = 153k ... Why am I reading 15.7k? I rechecked the resistor colour code and it is 220 k (red,red,yellow). If this is a correct reading, it could explain why the taper is so poor. This list will be long. I'll rechecking each connection. Simple test (my DMM doesn't have an speaker-diode test) using the lowest resistance setting. Close to 0 ohms means good connection. Results will be "GOOD" or "BAD" Connection:Toggle-B to BV.E -> GOOD Toggle-N to NV,2 -> GOOD Toggle-Hot to Jack.Hot -> GOOD Toggle-Gnd to Jack.Gnd -> GOOD Toggle-Gnd to NV.Gnd -> Good
|
|
|
Post by JohnH on Sept 21, 2012 16:15:19 GMT -5
Yes, I never built anything that worked first time either!
You are on the right lines with your multimeter.
The bridge side seems better, so I suggest starting with that, Assuming the guitar is still wired up (ie, you haven't taken it to bits yet!) just connect the meter across a guitar cord plugged in normally.
Set the toggle to bridge only, and check following, using a 200k setting on your meter:
All controls at full, all knobs pushed in, what is R? - it should be slightly less than that of the full B humbucker
Sweep the bridge tone control - there should be no change in R
Sweep the bridge volume control. Resistance should rise, reaching a max of about 80 to 90k at around knob position 6 to 7 (if a log pot, and allowing for 220k treble bleed), then down to zero at min volume.
Go to full volume again, and pull the Bridge single coil knob (I've forgotten which one that is), and resistance should about halve.
Repeat all above selecting only Neck pickup
There'll be more, but lets see those first...
cheers
John
|
|
|
Post by long813 on Sept 21, 2012 17:09:12 GMT -5
just connect the meter across a guitar cord plugged in normally. To clarify this. I have the cord pulled into the output jack and the other end is 'free'. One test lead to the 'free' end and one to the connector that is in the jack. BV Full, R = 16.3 k BV Off, R = 0 k NV Full, R = 499 k NV Off, R = 0 k S/P on BV varying. S/P on BT downMiddle, Parallel (down) BV, NV Full = 15.7 k BV Full, NV off = 0 k BV Off, NV Full = 0 k Middle, Series (up) BV, NV Full = 515 k BV Full, NV off = 16.3 k BV off, NV Full = 499 k S/P on BV up. S/P on BT varyingMiddle, Parallel (down) BV, NV Full = 515 k BV Full, NV off = 16.2 k BV Off, NV Full = 500 k Middle, Series (up) BV, NV Full = 15.7 k BV Full, NV off = 0 k BV off, NV Full = 499 k Bridge is measuring almost exact spec ... kind of odd. Neck measure suggests some more foul play. It can't be a o/c, but it seems to be just seeing the pot. Not sure where to go with that. Bridge - correct Neck - correct Bridge, Peak R = 91.2 k Neck, Peak R = 499 k Correct, after peak it drops eventually down to 0. Coil Cut is when BT and NT are pulled. Bridge R = 8.4 k Neck R = 499 k Neck coil cut doesn't work. Middle. BV up, BT up, NT up BV Full, NV Full, R = 502 k BV Full, NV off, R = 4 k BV off, NV Full, R = 499 k Thanks for these tests. I wouldn't have thought of these. I would have just spent endless amounts of time checking each connection.
|
|
|
Post by JohnH on Sept 21, 2012 17:40:54 GMT -5
Thats good info, and the bridge values all seem fine.
So, if you select bridge and play, does it sould OK, are you getting proper humbucker and single coil sounds - and bridge parallel (see below)?
back to resistance readings: With this version, if you pull just S4, you should get bridge parallel, which should read about 4k at full volume. Pull S3 and S3 to get bridge single at 8k.
the neck volume pot seems probably OK, but he nexk pickup is not looking connected. So , all knobs in and max settings, put your meter directly across all six possible pairs of neck pickup wires and measure resistance - no need to unsolder yet.
John
Do those check out?
|
|
|
Post by long813 on Sept 21, 2012 18:04:02 GMT -5
Thats good info, and the bridge values all seem fine. So, if you select bridge and play, does it sould OK, are you getting proper humbucker and single coil sounds - and bridge parallel (see below)? The guitar is not in a playable condition at the moment, but from what I remember, each switch did change the tone. I'll have to revisit testing that. Yes. BV full, BT up (parallel) R = 4.14 k Neck ConductorsNote that the Black/Green are soldered together W & R , R = 7.3 k W & B/G , R = 3.63 k W & Bare , R = 0 R & Bare , R = 7.29 k B/G & R , R = 3.67 k B/G & Bare , R = 3.62 k ...A problem appears
|
|
|
Post by JohnH on Sept 21, 2012 18:45:52 GMT -5
Seems the bridge is indeed likely to be fine. And the neck readings seem OK, if the neck pup is a more vintage type, with about 7.5k if normally wired? (please confiem)
So the question is, why is the neck not getting connected?
next step is to do resistance readings across the outer lugs of the neck volume pot - all knobs in, you should read about 7.3k. Pull the neck phase switch - this should make no difference. Put neck into single coil mode, and see you get the 3.6k ish reading.
(BTW - did you do the magnet flip on one pickup? If not, the neck wiring should move for best noise suppresiuon but that is not the cause of getting no sound from it, so we'll address that later. if needed.)
|
|
|
Post by long813 on Sept 21, 2012 19:13:49 GMT -5
Seems the bridge is indeed likely to be fine. And the neck readings seem OK, if the neck pup is a more vintage type, with about 7.5k if normally wired? (please confiem) Yes, the resistance measured on it's own was 7.22 k and SD's site has it as 7.72 k NV Full, down, Lug 1,3 ... R = 500 k (lug 1,2 ... R = 0) NV off, down Lug 1,3 ... R = 151 k (lug 1,2 ... R = 151 k) NV Full, up, Lug 1,3 ... R = 500 k NV off, up, Lug 1,3 ... R = 152 k Weird, a few posts above you can see that when I tested it, the measurements read ~ 15.7k (still would be wrong though) Coil Cut, NV Full, down, Lug 1,3 ... R = 500 k All I take out of this is that it's not seeing the pickup. No, I did not. I must have misinterpreted that part.
|
|
|
Post by JohnH on Sept 21, 2012 19:30:47 GMT -5
Ok, well th eneck pu is alright, but the neck volume is only showing its own resistance combined with et treble bleed resistor. You have isolated the problem, because the neck pickup goes to the phase switch then directly to the outer lugs of its volume pot. Something wrong with how the phase switch is wired, or the black and blue wires that go from phase to vol pot.
Once its going we can address the wire colour issues, phase hum etc.
john
|
|
|
Post by long813 on Sept 21, 2012 19:36:57 GMT -5
Ok, well th eneck pu is alright, but the neck volume is only showing its own resistance combined with et treble bleed resistor. You have isolated the problem, because the neck pickup goes to the phase switch then directly to the outer lugs of its volume pot. Something wrong with how the phase switch is wired, or the black and blue wires that go from phase to vol pot. Once its going we can address the wire colour issues, phase hum etc. john *Homer Doh* *Smash Head into Wall* The issue with drawing in pencil on graph paper ... I seem to have missed the connection from Lug1, NV to term D on S2 (with all the lines on the diagram I guess it's not to crazy that I missed it). This was an issue in the harness phase. I can't believe I missed that ... 5 times. Lets see what happens when I solder it up! It will be tricky! EDIT: With some cunning, it wasn't that bad. NT now read 7.17 k. Lets see how she performs now. EDIT 2: With quick tests, the floating ground issue seems to be also gone. There is no buzz when my hand does not touch the guitar. Need to test out all the configurations and then move onto the pickup flipping... Will post back soon.
|
|
|
Post by JohnH on Sept 21, 2012 20:11:19 GMT -5
Thats great.
If the pickup needs a change as discussed, you have a choice of flipping the magnet. or move the pickup wires around. Either will be fine with your open Hbs, so let me know if moving wires will be an easier fix.
The next resistance tests could be to check the series settings, which should be the sum of the two seperate individual pickup resistance readings.
Also phase tests - see the screwdriver pulloff test in the reference section.
And when you select two single coils - hum should be less than for one only (i suspect right now, it may not be so)
John
|
|
|
Post by long813 on Sept 21, 2012 20:17:54 GMT -5
Testing out each mode roughly.
Problems occurs. The Bridge volume is very low. I would say roughly half of what the neck pickup is on full.
I can't note any other issues at the moment. But I also am having a hard time distinguishing between the phases, parallel, series etcera.
|
|
|
Post by JohnH on Sept 21, 2012 20:32:04 GMT -5
OK, now the neck pup takes the lead as being nearst to being correct.
Neck pickup only: Is its single coil sound a bit less volume and more edgier sounding than full Hb? it should be.
Bridge pickup only - is its low volume problem also thin sounding, and does it get louder/deeper in single coil mode? - if so it could have one coil out of phase with the other.
J
|
|
|
Post by long813 on Sept 21, 2012 22:29:02 GMT -5
If the pickup needs a change as discussed, you have a choice of flipping the magnet. or move the pickup wires around. Either will be fine with your open Hbs, so let me know if moving wires will be an easier fix. Changing the wires, would probably be a lot tougher. After I'll take a look to see how much slack there is to pull the HB out. I can't quite say which is going to be best until I try it out. I have an entire binary spreadsheet of resistance values for every combination. I will type it up for for completeness. But, for series modes (neck position) NV-NT-BV-BT d-d-u-u ... R = 23.5 (N * B) d-u-u-u ... R = 19.9 (Nsc * B) d-u-u-u ... R = 12.1 (Nsc * Bsc) u-d-u-d ... R = 23.5 u-u-u-u ... R = 19.9 Also, I have a few positions I'm not quite sure about, they are: d-d-u-u ... R = 11.3 u-d-u-u ... R = 11.3 u-u-u-u ... R = 12.1 I think they are all for Nsc * Bsc, but I'm not sure. I don't have a jack to get the guitar into the PC, nor an analog meter to test this. I'll come back to this test. There are differences, but I'll need to switch to a real amp to try it out the one I'm testing this on is quite terrible. When in HB mode it's low volume, when BT is up it decreases volume and sound like the tone control is on 1-2 then when the NT is up the volume is decreased even more so and the tone sound like you're hearing it through a wall. Thanks for all your help thus far JohnH! It's greatly appreciated. EDIT: Here is the spreadsheet. All possible combinations. No distinction between hum-cancelling and non yet. docs.google.com/spreadsheet/ccc?key=0AjoPApW2_-GIdEZIdm4yeEh2OExmQWxwU015TFYzWEE
|
|
|
Post by JohnH on Sept 21, 2012 22:55:19 GMT -5
Those R values alos seem OK to me.
Just to be clear, when Im talking of moving wires around, I dont mean inside the pickups, just where each one is attched to the switches.
Also, just a thought: if you are testing with an amp not intended for guitar, might it have a low input impedance? that would explain low output and dull sound. A switched off, non true bypass pedal between guitar and such an amp might help, or a guitar processor etc.
|
|
|
Post by long813 on Sept 21, 2012 23:03:39 GMT -5
Those R values alos seem OK to me. Also, if you'd like you can check the spreadsheet to see if there is any thing that strikes you as odd. Oh yes, I know, but that's the part that's hard If there is enough slack to take the PU and dissasemble it, it would be easier I think. If not, there really isn't another option. The amp one I got with my very first guitar. I test on it first to hope nothing blows up, then I switch back to my other one, so I've been using a real amp after initial testing. The volume differences are apparent on either amp though. Bridge is low, neck is seemingly normal.
|
|
|
Post by JohnH on Sept 21, 2012 23:58:18 GMT -5
The spreadsheet values seem fine - assuming the right column is for toggle in centre position.
Maybe check tone pot and tone cap connections? A short there could dull the sound, without affecting the R readings, being through the tone cap.
does the neck tone control work ok?
|
|
|
Post by long813 on Sept 22, 2012 13:52:50 GMT -5
The spreadsheet values seem fine - assuming the right column is for toggle in centre position. Good to know! And yes, I did a copy paste but forgot to edit the header. Fixed now. Have any suggestions on how to do with with out an analog meter? I don't think the 'typical' way of testing oc or sc works with DMMs. Both BT and NT do seem to work, rolling off the frequencies, but it sounds like the Bridge volume max is at half volume in comparison to the Neck volume. I'm going to continue to check through each connection, maybe I missed something that is destroying the volume range. I may try to take some audio samples, although they would be very half assed - using a laptop mic and all. EDIT: Resistance Measurements Between Capacitors... NT. 22nF. Lug 3 to D ... R = 6.9 K BT. 22nF. Lug 3 to GND ... R = 15 K NV. 1nF // 220 K. Lug 1 to Lug 2 ... R = 6.9 K BV. 1nF // 220 K. Lug 1 to Lug 2 ... R = 15 K Although, I don't think this actually tells us anything.
|
|
|
Post by JohnH on Sept 22, 2012 16:06:35 GMT -5
To check the tone circuits, it was more a close visual inspection that I was thinking of, looking for bits of wire touching wah they shouldnt, solder blobs, and just confirming each lug is cprrect etc
I think we need to try to hear the bridge pickup and its V and T controls, isolated from the neck. But I think its best to find out what we can without desoldering because it can all end up as a mess.
So try this with an amp.
Dont plug into the guitar, but clip some leads to the end of the cord and connect the jack barrel to a ground point on the guitar (eg one of the braids, bare wires or switch tops), and connect the jack tip to the centre lug of the bridge volume pot.
Now set the toggle to the neck, all knobs in and play - it should be playing the bridge properly?
Keep connections as above, but pull the series/parallel switch S1. It should also just be playing the bridge? any good?
In the above tests, try with different bridge tone and volume settings, and confirm that the neck controls do nothing in this case.
also, in the above tests if you move the toggle to the bridge, does it make any difference?
|
|
|
Post by long813 on Sept 22, 2012 16:45:40 GMT -5
To check the tone circuits, it was more a close visual inspection that I was thinking of, looking for bits of wire touching wah they shouldnt, solder blobs, and just confirming each lug is cprrect etc Ok then, yes I've check the connections. Definitely! Yes. Bridge plays. Neck position - Sounds like bridge, lower volume Middle position - Sounds like both, much louder Bridge position - Sounds like bridge, lower volume Yes. In Neck, Middle, Bridge position there is no change and it sounds like the bridge pickup Sounds like there is also more hum when out of phase as well. Yes, the NV and NT do not affect the bridge pickup. BV and BT do affect the pickup Addressed above.
|
|