Page 1 of 2 12 LastLast
Results 1 to 35 of 56
Like Tree5Likes

Thread: Circuits involve active electronics and a dummy coil.

  1. #1
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951

    Circuits involve active electronics and a dummy coil.

    I did some research and so far I found one design used in the Fender Elite Strat and one in Ernie Ball Silent circuit where both use active electronics to isolate the dummy coil from the main pup. Is there any other design out there? If so, can anyone show me the link or schematic?

    Thanks

    Alan

  2. #2
    Senior Member
    Join Date
    Nov 2007
    Location
    Kansas City, MO USA
    Posts
    128
    I don't have any info but I'm very interested in this. I was just about to try a Suhr type passive dummy coil because my friend (a gifted luthier) is interested in noiseless stuff; however I hate the idea of routing a strat like.

    The Fender Elite looks like a fantastic idea.





    After seeing that, here's what I'm gonna try: simple TL072 buffer after dummy coil, same thing at the normal output point of guitar circuit, combine. Switch in an additional dummy coil in parallel with the first one in positions 2&4. Assumptions: swimming pool route, 4-pole switch, unity gain all around.

  3. #3
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    I tried something similar already, you have to add inverted circuit for the middle pup as it is opposite polarity. One thing that does not work, you cannot have the tone control in the normal way because when you turn the tone pot up, you cut off the high frequency noise of the main pup. But the dummy pup still sense the high frequency noise and go into the main signal as there are no opposite noise from the main pup to cancel them.

    I am looking for something different from the two I mentioned. I wonder whether there are any other designs on the market.

  4. #4
    Senior Member
    Join Date
    Nov 2007
    Location
    Salt Lake City
    Posts
    200
    Try using a differential amplifier or an instrumentation amplifier. Dummy coil on one input, pickup on the other.

    I have also seen a circuit that uses a buffer for the dummy coil and the output of the buffer is used as the "ground" for the single coil. I think One of the guys here designed it. Joe Gwinn maybe?

    cheers
    Ethan

  5. #5
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by CRU JONES View Post
    Try using a differential amplifier or an instrumentation amplifier. Dummy coil on one input, pickup on the other.

    I have also seen a circuit that uses a buffer for the dummy coil and the output of the buffer is used as the "ground" for the single coil. I think One of the guys here designed it. Joe Gwinn maybe?

    cheers
    Ethan
    No, Ethan, I did that. It should come up in a search. I will try to remember to do that later, although it should not be hard for anyone to find. The idea is that the pickup remains passive; just the dummy has a buffer. A single FET can be used, running on a few volts and well under 1 ma.
    CRU JONES likes this.

  6. #6
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    Quote Originally Posted by CRU JONES View Post
    Try using a differential amplifier or an instrumentation amplifier. Dummy coil on one input, pickup on the other.

    I have also seen a circuit that uses a buffer for the dummy coil and the output of the buffer is used as the "ground" for the single coil. I think One of the guys here designed it. Joe Gwinn maybe?

    cheers
    Ethan
    That is the Ernie Ball design. I designed both on my own without knowing it. I only found out through the patent search. This one has no restriction on the tone pot.

  7. #7
    Senior Member
    Join Date
    Nov 2007
    Location
    Salt Lake City
    Posts
    200
    Quote Originally Posted by Mike Sulzer View Post
    No, Ethan, I did that. It should come up in a search. I will try to remember to do that later, although it should not be hard for anyone to find. The idea is that the pickup remains passive; just the dummy has a buffer. A single FET can be used, running on a few volts and well under 1 ma.
    Ah, Thanks Mike! A very simple and clever design! I was impressed when I saw it Do post the circuit again, if you don't mind.

    Sorry about that,
    Ethan

  8. #8
    Senior Member
    Join Date
    Nov 2007
    Location
    Salt Lake City
    Posts
    200
    Quote Originally Posted by Alan0354 View Post
    That is the Ernie Ball design. I designed both on my own without knowing it. I only found out through the patent search. This one has no restriction on the tone pot.
    Alan, So are you saying the diff amp/ instrumentation is protected?

    I would argue that, that design is "obvious to people skilled in the art" (such as yourself).

    Ethan

  9. #9
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    Quote Originally Posted by CRU JONES View Post
    Alan, So are you saying the diff amp/ instrumentation is protected?

    I would argue that, that design is "obvious to people skilled in the art" (such as yourself).

    Ethan
    The Ernie Ball design is not differential. It is driving the ground side of the pup with the anti noise, the drive is low impedance so even if you take out the battery, you still can keep playing but with no hum cancelling. I read the patent very carefully as I designed to same thing on my own. The Elite Strat design is no big deal, that was the first one I designed and failed because of the tone control.

    It is the concept they patent, not the scale of electronics.

  10. #10
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by CRU JONES View Post
    Ah, Thanks Mike! A very simple and clever design! I was impressed when I saw it Do post the circuit again, if you don't mind.

    Sorry about that,
    Ethan
    Thank you for bringing it up, Ethan. Here is the circuit. The dummy coil should be like the pickup, but some more turns since the adjustment works only in the attenuation direction.

    buffereddummy.png

  11. #11
    Senior Member
    Join Date
    Nov 2007
    Location
    Salt Lake City
    Posts
    200
    Quote Originally Posted by Alan0354 View Post
    The Ernie Ball design is not differential. It is driving the ground side of the pup with the anti noise, the drive is low impedance so even if you take out the battery, you still can keep playing but with no hum cancelling. I read the patent very carefully as I designed to same thing on my own. The Elite Strat design is no big deal, that was the first one I designed and failed because of the tone control.

    It is the concept they patent, not the scale of electronics.
    The Ernie ball sounds like Mike Sulzers design

    If I understand you correctly... The tone control fails because it is before the active circuitry, no? The elite circuitry is: Two boosters built around Q1 and Q5. Q1 boosts the pickup, Q5 boosts the Dummy. The boosted signals are summed in mixing resistors R5 and R24. The discrete op-amp is only for the mid-boost, we can ignore that. Why not put your tone control after the mixing resistors?

  12. #12
    Senior Member
    Join Date
    Nov 2007
    Location
    Kansas City, MO USA
    Posts
    128
    Holy crap that EB/Mike Sulzer circuit looks fantastic! Questions about that:

    How does it perform IRL?Does it do a good job cancelling hum? Is the sound/feel pretty much the same with it as without?

    I don't quite grok how the signal from the dummy coil buffer combines with the pickups. I've only ever seen audio circuits that combine signals on the other side... I guess being AC it doesn't matter? I'm missing a concept here... Help?

  13. #13
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by Kindly Killer View Post
    Holy crap that EB/Mike Sulzer circuit looks fantastic! Questions about that:

    How does it perform IRL?Does it do a good job cancelling hum? Is the sound/feel pretty much the same with it as without?

    I don't quite grok how the signal from the dummy coil buffer combines with the pickups. I've only ever seen audio circuits that combine signals on the other side... I guess being AC it doesn't matter? I'm missing a concept here... Help?
    To understand this circuit, let's start by thinking about putting a dummy coil and a pickup in series, with the dummy on the low side, that is one side connected to ground. That works, but the inductance goes up , and the resonant frequency goes down, and so the sound is changed. (One way around this is to use a coil with a large area (Suhr), to get good sensitivity, but few turns, to keep the inductance down. This is another approach.) Suppose we could replace the dummy with a circuit that had the same output voltage, but a much lower output impedance. Then the hum would still be canceled, but we would not have the increase in inductance. That is what the FET does when connected in this way with the dummy as input. It is a source follower, with a gain of just under unity. (This is why we want to make the dummy a bit more sensitive than the pickup. Also we want to leave a bit of room for adjustment.)

    The circuit only has to put out a few mv, that is, the hum voltage, and it also has to sink the current from the pickup signal, which is very small since the impedance is very high. So the circuit can run on low voltage and current. It cancels hum as well as a dummy can. How does it affect the sound? OK, I used those 10K pots because I had them. I would have preferred 5K or 3K. But the circuit is set up so that you adjust maybe 10% of the way down from the top of the pot. So the impedance looking into the pot slider is a bit less than 1K in series with the output impedance of the source follower, which is probably a few hundred ohms. So the impedance is a bit over 1K. To get an idea of how that influences the tone, think about how the volume control affects it. If you turn it down a significant amount, the tone changes. But if you turn it down just a bit, there is no significant effect on the tone. That is how much this circuit affects the tone. (The volume control used in this way puts a similar value of resistance in series with the pickup.)

  14. #14
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    I did not know about the Ernie Ball design/patent. From the patent it is clear that he has an unnecessary complication in the design, adjustable loading on the dummy to get the frequency response right. From the explanation above, it should be clear that infinite load is correct and no adjustment is necessary as long as the dummy is very much like the pickup.

  15. #15
    Pickup Maker David Schwab's Avatar
    Join Date
    May 2006
    Location
    Staten Island, NY
    Posts
    10,924
    Quote Originally Posted by Mike Sulzer View Post
    No, Ethan, I did that. It should come up in a search. I will try to remember to do that later, although it should not be hard for anyone to find. The idea is that the pickup remains passive; just the dummy has a buffer. A single FET can be used, running on a few volts and well under 1 ma.
    Here it is.

    buffered-dummy-coil.png

    I used to have a schematic for a G&L guitar that had the output from the dummy coil's op amp going to the ground side of a pickup. I can't find it anymore though.
    It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. Albert Einstein

    www.sgd-lutherie.com
    www.soundcloud.com/davidravenmoon
    SGD Lutherie Facebook page

  16. #16
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    So are the two design mentioned the only ones on the market or patented?

  17. #17
    Old Timer
    Join Date
    May 2006
    Location
    Boston, MA area
    Posts
    2,578
    Quote Originally Posted by Mike Sulzer View Post
    No, Ethan, I did that. It should come up in a search. I will try to remember to do that later, although it should not be hard for anyone to find. The idea is that the pickup remains passive; just the dummy has a buffer. A single FET can be used, running on a few volts and well under 1 ma.
    Yes. I don't recall having published a circuit, although I may have commented on some of them.

  18. #18
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    Anyone know of any other active noise cancelling design other than the two mentioned?

    I read from a few comments that the EB did not really work out very well. I listened to the demo of the Suhr, not only it does not cancel very well, it change the sound a little also. For that kind of money, Suhr can keep it.

  19. #19
    Senior Member
    Join Date
    Nov 2007
    Location
    Kansas City, MO USA
    Posts
    128
    I tried Mike Sulzer's circuit but I think something is missing from the schemo that I'm too ignorant to catch. I have it in my pile of stuff to come back and try but I don't know when I will ever get to it.

    It would be super-fantastic-wonderful if Mike would draw this up as a complete OS project. (unsubtle begging)

    I also tried the Illitch [/Suhr] type low impedance dummy coil in series approach - I just followed the recipe in the patent verbatim. It worked great on a disembodied pickguard, but when I stuffed it into a guitar it didn't reduce enough hum that I thought it would be worthwhile. I'm very distantly considering buying one of Suhr's for one of my strats and try to clone it for my other one, but realistically I probably already spent all the time on this that I'm going to.

    Part of my approach to all of this is that the problem of hum kinda takes care of itself. Seems like the big productions I play in never have hum problems - it's only at the rowdy places where people drink a lot of beer (where they have a lot of neon signs). I almost feel like a noisy guitar amp humming between songs - or during soft parts - is part of the ambiance of those places. It's like an idling motorcycle motor or something - and they can't wait for me to peg the tach LOL

    Oh yeah - the reason I'm replying: I built what I described in my first post - output of 5-way switch into preamp, plus output of dummy coil into preamp, combined after the pre. I used the Tillman pre instead of opamp. Tone controls and volume are 25k pots, switched separately on a 4-pole switch. Works perfectly as far as canceling hum, but it sounds and feels WAY different. I considered it for about 1.5 seconds and ripped it out.

  20. #20
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by Kindly Killer View Post
    I tried Mike Sulzer's circuit but I think something is missing from the schemo that I'm too ignorant to catch. I have it in my pile of stuff to come back and try but I don't know when I will ever get to it.
    Did you measure the dc voltage at the top of the 27K resistor (at the connection to the FET)?

  21. #21
    Senior Member
    Join Date
    Nov 2007
    Location
    Kansas City, MO USA
    Posts
    128
    I did. I don't remember the exact number, but it was reasonable...

  22. #22
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by Kindly Killer View Post
    I did. I don't remember the exact number, but it was reasonable...
    OK, good. If you connect the dummy coil directly to the amp and listen for the hum, and then connect it to the circuit, jumpering across the pickup, do you get a similar level of him, but maybe more higher frequency buzzing?

  23. #23
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    Quote Originally Posted by Mike Sulzer View Post
    I did not know about the Ernie Ball design/patent. From the patent it is clear that he has an unnecessary complication in the design, adjustable loading on the dummy to get the frequency response right. From the explanation above, it should be clear that infinite load is correct and no adjustment is necessary as long as the dummy is very much like the pickup.
    In my design, I use op-amp, I invert the signal for the middle pup so even when you are in position 2 and 4 when both circuit are combined, the effect cancel out.

    What do you mean by adjusting the load on the dummy coil to get the frequency response? I did put a 250K volume pot as a variable resistor across the dummy coil and adjust the load and I cannot get rid of the noise at all!!! I tried using a lag lead network ( a cap or different value in series with the 250K pot) and cannot get rid of all the noise. Mainly the buzzing where you see like a spike and a few rings of about 10KHz riding on the 120Hz at the same point. Getting rid of the 60 and 120 is very easy, the buzzing is the kicker. The Suhr don't work very well in the demo either.

  24. #24
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by Alan0354 View Post
    In my design, I use op-amp, I invert the signal for the middle pup so even when you are in position 2 and 4 when both circuit are combined, the effect cancel out.

    What do you mean by adjusting the load on the dummy coil to get the frequency response? I did put a 250K volume pot as a variable resistor across the dummy coil and adjust the load and I cannot get rid of the noise at all!!! I tried using a lag lead network ( a cap or different value in series with the 250K pot) and cannot get rid of all the noise. Mainly the buzzing where you see like a spike and a few rings of about 10KHz riding on the 120Hz at the same point. Getting rid of the 60 and 120 is very easy, the buzzing is the kicker. The Suhr don't work very well in the demo either.
    The correct load on the dummy is infinity. See post 13 above. The idea is to think of the equivalent circuit of the dummy when it is in series with the pickup, and then make a circuit that puts the same voltage in series with the pickup, but with a low impedance. I do not think that it is perfect as you approach the self-resonance of the coils (maybe 15 KHz), but it should be pretty good even at that high a frequency.

  25. #25
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    Quote Originally Posted by Mike Sulzer View Post
    The correct load on the dummy is infinity. See post 13 above. The idea is to think of the equivalent circuit of the dummy when it is in series with the pickup, and then make a circuit that puts the same voltage in series with the pickup, but with a low impedance. I do not think that it is perfect as you approach the self-resonance of the coils (maybe 15 KHz), but it should be pretty good even at that high a frequency.
    I tried infinity also. No matter how you play with the loading, you can't get rid of the hum. As I said, getting rid of the 60 and 120 is easy, by the buzz is a different story. Yes you hear it lower, but not cancelling. Nothing like the true humbucking pup. You have to have very very similar coil for the dummy to get a better effect.

  26. #26
    Supporting Member
    Join Date
    Sep 2007
    Posts
    2,859
    Quote Originally Posted by Alan0354 View Post
    I tried infinity also. No matter how you play with the loading, you can't get rid of the hum. As I said, getting rid of the 60 and 120 is easy, by the buzz is a different story. Yes you hear it lower, but not cancelling. Nothing like the true humbucking pup. You have to have very very similar coil for the dummy to get a better effect.
    Yes, the coils have to be very much the same. In the circuit with the FET you need a bit more sensitivity on the dummy, and so you can never be perfect at the high frequencies. In my case, if you turned the gain up very high you could hear a sort of wispy sound, the effect of the highest harmonics not canceling. You have a bit more flexibility with the op amps, but maybe more amp noise as well.

    Are you sure all your noise is magnetic and not some from electric fields, which do not cancel?

  27. #27
    Old Timer
    Join Date
    Oct 2011
    Posts
    1,951
    Quote Originally Posted by Mike Sulzer View Post
    Yes, the coils have to be very much the same. In the circuit with the FET you need a bit more sensitivity on the dummy, and so you can never be perfect at the high frequencies. In my case, if you turned the gain up very high you could hear a sort of wispy sound, the effect of the highest harmonics not canceling. You have a bit more flexibility with the op amps, but maybe more amp noise as well.

    Are you sure all your noise is magnetic and not some from electric fields, which do not cancel?
    Yes I am very sure because I have shield cavity. It really not depend of the shielding.

    You can find opamp that is very low noise. I use MC33178 or MC33179 that work with +/-2V, only draw about 1.6 or so mA supply. I yet to find a lower or equal voltage noise spec that draw less, in $1.50 range each and 3MHz BW. 4558 draw more than twice the current.

    Good thing about opamp is I drive direct and the impedance is very low, that's the reason I use a 3MHz opamp so the output impedance is theoretically zero ohm at 20KHz. And I can adjust the gain of the dummy signal without effecting the impedance.

  28. #28
    Supporting Member Steve A.'s Avatar
    Join Date
    May 2006
    Posts
    3,868

    Digging up an old thread to add some irrelevant comments...

    FWIW when using passive dummy coils in strats it was easiest for me to wire them up in series between the "tail" of the volume pot and ground. I thought that worked great until I was playing in one of those Bars from Hell which would be a real nightmare with single coil pickups. As I recall the dummy coil worked fine at full volume but as you turned the control down the hum would come back. (I haven't done much with dummy coils since then- I never got around to trying a Suhr-style circuit which uses two pots although I did wire up a low impedance coil with 32GA magnet wire.)

    Steve Ahola

    P.S. The Gibson Blueshawk has a very interesting circuit using two P-90's and a passive dummy coil. The two pickups are RWRP with respect to each other and the selector switch inverts the leads from the dummy coil so that there is hum-cancellation in all positions (no need for the dummy coil in the middle position).

  29. #29
    Pickup Maker David Schwab's Avatar
    Join Date
    May 2006
    Location
    Staten Island, NY
    Posts
    10,924
    Quote Originally Posted by Steve A. View Post
    FWIW when using passive dummy coils in strats it was easiest for me to wire them up in series between the "tail" of the volume pot and ground. I thought that worked great until I was playing in one of those Bars from Hell which would be a real nightmare with single coil pickups. As I recall the dummy coil worked fine at full volume but as you turned the control down the hum would come back.
    Because now you were just hearing the dummy coil.
    It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. Albert Einstein

    www.sgd-lutherie.com
    www.soundcloud.com/davidravenmoon
    SGD Lutherie Facebook page

  30. #30
    Supporting Member Steve A.'s Avatar
    Join Date
    May 2006
    Posts
    3,868
    Quote Originally Posted by David Schwab View Post
    Because now you were just hearing the dummy coil.
    In "normal" environments (i.e. at home) it seemed to work great. And it was only in the middle range of the pot that the noise came back; once you passed the midpoint the hum went away again. But that was definitely the wrong way to hook it up- I should have inserted between the pickup grounds and the guitar ground but I was doing series/parallel switching so that would have gotten complicated...

    I need to get back into dummy coils for some of my steel guitars. Like the 10 string Alkire E Harp that I just got...

    alkire-e-harp-case.jpg


    Steve Ahola

  31. #31
    Senior Member
    Join Date
    Dec 2010
    Posts
    199
    I'm considering this for a two pickup RW/RP guitar, which necessitates invertering the coil for one of the pickups. My question is - I understand that the follower described above adequately buffers the dummy, but what about the inverting leg of a single transitor phase inverter? It's much higher impeadance, right?

    Consider this:


    The boxes are pickups, I slapped in values from a similar pickup. And what about leaving the big honking inductor that is a pickup flapping in the breeze when it's not in circuit? In a passive guitar circuit, they do no harm, but here you've got the end of an inductor that's AC coupled on one end into a circuit thats still functioning.
    CRU JONES likes this.

  32. #32
    Senior Member
    Join Date
    Nov 2007
    Location
    Salt Lake City
    Posts
    200
    Nate,

    I like it! Try it!

    The impedance of your transistor circuit will be minute compared to your pickups impedance.

    You might also consider a means to "balance" the Hum generated by the dummy with the Hum generated by the pickups.

    Maybe experiment with capacitively bypassing the Bias network. Technically, an LR is formed by R1||R2 +Rd... Possibly completely inconsequential.

    Nice work, good luck!
    Ethan

  33. #33
    Senior Member
    Join Date
    Dec 2010
    Posts
    199
    I considered putting in balance but decided against it for a couple reasons. First off, the dummy coil is going to be another GFS Mean 90 that I rip apart and put just the coil in the space between the neck and bridge pickups. So it will be exactly matched with the bridge pickup, and nearly exactly matched with the neck. (Which btw, the RW/RP both pickups on position cancels very well.) Second, this guitar is a top routed strat, with a pickguard and 24 fret overhang (it's a Warmoth 24.75" scale conversion neck, so the overhang is about the same as a 22 fret neck). You can tweak for hum balance with the pickguard out, but once it goes together, I do not want it drifting. The neck's already been off and back on more than I'd like getting electronics tweaked (it has a Graphtech Hexpander/Acoustiphonic also.)

    I considered (and drew up) an alternate where the neck and bridge pickups were DC coupled to the phase inverter (and thus have a DC path to ground always) - and to their individual emitter followers. But the Graphtech already buffers the magnetic output, and there is no tone control in the guitar, so the only benefit that has is in the location of the buffer.

  34. #34
    Senior Member
    Join Date
    Nov 2007
    Location
    Salt Lake City
    Posts
    200
    That makes sense.

    Does it have a middle position?

  35. #35
    Senior Member
    Join Date
    Dec 2010
    Posts
    199
    Yes - it has a 3 way blade switch. The guitar is a schizophrenic combination of Luddite and High tech. It contains a Graphtech Ghost piezo saddle / 13 pin MIDI out, with P90's in a humbucker box, and minimalist controls. 3 way blade, and two volume knobs (three actually, magnetic and MIDI volume are stacked on the "volume" knob, the second "tone" knob is the summed Piezo volume, and contains a pull switch wired to the 'Dark' switch on the Acoustiphonic preamp. Magnetic & Piezo are always in 'blend' mode and manipulated by the volumes. If you're interested, you can find more over at the unofficialwarmoth forums. There's some finished pictures and a very long tortuous build thread.

    Minor edit: bypassed the bias divider, added DC path to ground on the high impeadance side of the pickups.


    Will the 2.7M to ground create a significant noise source? Since it's a 3 - way, maybe just putting it across the switch pins is enough to tame any pops, let the volume ground take care of things.
    CRU JONES likes this.

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 1
    Last Post: 10-20-2011, 06:20 AM
  2. active dummy coil, series or parallel
    By Amplexus in forum Pickup Makers
    Replies: 6
    Last Post: 01-04-2010, 01:31 PM
  3. Fine tuning strat single coil pups with a dummy coil?
    By Silent Bob in forum Pickup Makers
    Replies: 0
    Last Post: 11-04-2007, 07:15 AM
  4. Dummy coil question
    By truetone in forum Pickup Makers
    Replies: 19
    Last Post: 04-30-2007, 09:27 PM
  5. suhr and dummy coil...
    By swt in forum Pickup Makers
    Replies: 23
    Last Post: 09-08-2006, 06:44 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •