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borge

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Posts posted by borge

  1. It looks like your two diagrams are electrically identical,the only difference is the physical location of the batteries earth,it's earthed at the jack in the 2nd pic and the earth pad on the PCB in the first.

    To disconnect the passive signal from the circuits input when the circuit isn't in use (ie when the bass is plugged into an amp) you need to break the connection between the left lug of the passive vol. pot. and the circuits input (it's a red wire) when a lead is plugged in.

    Jack 'IX' in this link is what you need.

    http://www.switchcraft.com/Documents/Jack_Schematics.pdf

    wired:

    top lug-left lug of vol. pot.

    2nd lug- PCB input

    3rd-passive output from centre lug of vol'pot'

    4th-earth

    this'll stop any loading of the passive output when plugged into an amp, but you still have the problem of the circuit being on at all times and draining the battery.

    If you could get a hold of the circuit's schematic or the input impedance from the manufacturer you could get an idea of whether the loading will be an issue.

  2. having the signal going to the active circuit at all times will almost definately load down the output, whether it'll be a problem depends on your taste and the circuit.

    I'd suggest using a switching output jack that'll dissconect the signal from the active circuit when a lead is plugged in. Assuming, of course, you won't want to use both the internal speaker and and external amp at the same time...

  3. Thanks for a reply.

    It appears everything else functions. I am using this metal braided wire for the hot output jack. That must be the issue. I was using a separate wire for the ground.

    When I touch the metal jacket of the hot wire while its hooked up, it buzzes louder, when I press it to a grounded pot, it diminishes a bit.

    What are the rules or advice for doing output on this guitar? I just ordered some new guitar wire that I think will better suit it. This metal braid stuff seems to be more for an old Les Paul style.

    All signals should be in sheilded cable, then the need for additional sheilding (copper tape ect) is reduced/eliminated.

    Any unearthed sheilding will increase noise.

    get rid of the single ground wire, connect the sheilded cable to the jack sleeve and the back of a pot.

    Earth loops/star grounding aren't always a big concern, all fenders have earth loops-the pots are earthed via the foil sheild AND by wires soldered to thier backs..relying on just the sheild would've been cheaper and (probably inperceivably) quieter, yet leo scrounge fender sprung for both for reliabilities sake :D or something like that :D

  4. so ideally I dont want to even use the two pot positions. I was thinking I could use a concentric volume pot to control the volume of both pickups with one knob and still keep the signals separate for the stereo jack.

    sounds like you want a dual ganged pot, not a dual concentric pot?

    I'm a bit confused by your explaination. So if i'm understanding correctly here goes the simplist route i can think of...

    outputs of pickups go to dual pots, then onboard pickup selector of your choice then jack tip - mono operation complete.

    stereo operation - put onboard selector switch to 'neck' pos. (neck sent to jack tip) flick 'stereo-mono' switch (a spst only is required) which connects bridge signal to jack ring.

    unless you want to go active and design a circuit which will recognise weather a TS or TRS jack is inserted and switch to mono or stereo accordingly...

  5. I dont even know if wiring them to split a humbucker is possible.

    Just saw this in the OP, splitting one HB only requires a latching SPST.

    Of itself that is not a problem. You can use a momentary switch (with appropriate debouncing) to electronically re-route pickup output into different configurations such as coil tap, etc. It just means that the switch will not carry the pickup signal and the internal impedance of the guitar circuit will become "active". Not a bad thing in my book though.

    Not necessarily, the momentary switch could energise a SPST relay to do the coil splitting switching, no need for the guitar signal to have any active circuitry :D but no need really:

    The microswitches in arcade switches are the same as you'd find in washing machines, dishwashers and a myriad of other applications, your local appliance repair shop will have a big box of them laying around, take your momentary one in and they may swap it for a latching one or sell you one for a few dollars :D

  6. yes, and it's a fact modern test equipment is more acute than ANY human ear :D

    ie EJ's claim could be easily discredited by a simple test, not that that's required, anyone with electrical knowledge could tell you a slight variation in series resistance will cause a slight voltage change, but nothing compared to the normal variation due to power grid loading - ie the mains voltage variation throughout the day due to changing demand on the grid is many times larger than the voltage variation due to a possible slight difference in series resistance between two different fuses. I digress..

  7. playing guitars at a music shop will not give any useful data, humans are too subjective and prone to placebo.

    its true - but its that same subjectivity we use when choosing a guitar and listening to music. I dont need scientific tests to tell me a piece of music sounds good and i dont need scientific tests to tell me if a guitar sounds good - its all about what pleases my imperfect human ears.

    Because music is art and therefore subjective, the frequency spectrum of different woods is not :D one is measurable the other is not.

    You saying a guitar 'sounds good' means about as much as me saying the same guitar doesn't 'sound good', they're just opinions, nothing more, nothing less, It has no bearing on comparing the sound of "sapele vs mahogany" or any other woods.

    now i know that when i play a few guitars made the same way with the same materials my imperfect human ears will notice differences.

    And so will mine, but you and I expect differences whereas bartbrn doesn't, we both hear what we expect/want to hear..

    I am doing some tests at the moment with capacitors, i am not against the idea of studying these things but i wont call it science as its really not. It involves a switching system to allow me to see which i prefer with my imperfect human ears. So far i am actually finding very little difference, i will admit its less than i expected. its certainly tiny compared to the difference i hear with my imperfect human ears when switching between two otherwise identical guitars

    yet other claim to hear the difference between capacitors and pay a premium for PIO, or bumblebee caps... who's right? you or them?

    You can see an interesting comparison of caps here:

    http://freestompboxes.org/viewtopic.php?f=6&t=12118&hilit=scientific

    (sorry, think you may need to join the forum to access it, but it's well worth it, and a great forum to boot)

    I would like to see the same frequency comparison software used for bartbrn's experiment, then we would have some actual facts to go off :D

  8. 2) The human ear CAN tell a difference. If you don't believe us, go do what Wez suggested. At minimum, address his comments.

    playing guitars at a music shop will not give any useful data, humans are too subjective and prone to placebo.

    And let's ne clear on something. We're not talking about pitch, but tone. An open A will still vibrate at 440Hz (IIRC) on every single guitar out there. It will sound different though because the wood will effect the WAY it vibrates.

    No, the fundamental note (440) will vibrate identically, the amplitude of each harmonic will determine it's 'tone'. All easily measurable with test equipment to give useful, comparable data.

    Prostheta-ANYTHING can be quantified in the lab, you just need a large enough sample size B)

    I believe the woods used do make a difference but until I see some actual evidence I wont be spouting my easily biased, placebo ridden findings to anyone. from where I stand the sun appears to rotate around earth, I keep that to myself also...

    If we all took what we, or others 'hear' as useful data then buying things like THIS should seem totally normal :D what effect tacking on 2m of high quality cable to the masses of the lowest possible cost (while meeting safety specs) cable leading to that point would have is beyond me...but if someone hears it, power to them. :D

  9. How about using 500k volume pot and putting a resistor across lugs 1 and 3 to lower the resistance? I havent done the math yet but if I get the pot down to the 300-400 range it might be a decent compromise.

    That will also affect the taper.

    You can get 300k pots quite easily. most pots (and other electrical components) have a tolerance of +/-20% so your average 300k can be anywhere between 240k and 360k, a 250k pot will be between 200k and 300k and so on... it's very possible a '300k' pot will have a lower value than a '250k' pot, ie don't worry about it to much :D

  10. using extra poles to load down the neck and mid. pups (making the darker pups even darker..) seems like a waste of a super switch to me....turning down a 500k pot to 8-9 is the same as using a 250k pot (or using an expensive superswitch to simulate it..)

    I mean, why not use a pup set that match tonally rather than using an expensive switch to waste signal to earth??

    I'd use 500k pots and put the superswitch to better use :D

  11. I'd still like to be able to switch between all three options on the humbucker, but could you suggest a usable way to do this?

    Which three options?

    with a humbucker (or any two coils) there's:

    standard HB

    South coil only

    North coil only

    both coils in parallel

    both coils in parallel out of phase

    both coils in series ooP

    As it is you have the first three.

    ooP tones are generally low output, thin and nasal, not something many people have a use for. I've only found much use for it if there's individual volumes so you're able to mix a varying amount of the ooP tone to thin it out.

    This may suit better: master volume, master tone (with 'woman tone' switch if desired) mid volume, mid phase switch, bridge coil switch.

    you'd get:

    bridge HB

    Br south coil

    Br north coil

    br HB + mid

    Br south coil + mid

    Br north coil + mid

    mid

    mid + neck

    neck

    br HB + mid ooP

    Br south coil + mid ooP

    Br north coil + mid ooP

    mid

    mid ooP + neck

    of course, the mid can be varied independently whenever it's selected.

    BTW bridge ooP + mid is identical to mid ooP + bridge ect that's why i suggest phase switching the mid not bridge, you get the same br + mid ooP tones but also get Neck + mid ooP as well.

  12. The idea being that when the 5-way switch is set to the middle+bridge position, the coil tap will select the single coils in the humbucker (one will be out-of-phase and one will be in-phase).

    Neither will be out of phase, one will be hum cancelling, one won't.

    The second toggle will give the ability to switch-in an extra tone capaciter of large or small value (or be off).

    What is the purpose of the 270k and 1M resistors? they load your circuit and bleed high end even when your tone switch is 'off', your tone switch is like the Gretsch's one except for these... in the neck+mid pos. you have the equivalent of 5 pots loading your signal down, not ideal...

    And I'm not sure if I'd call .043 (.01 and .033 in paralleled) and 0.033 'large and small values', there's only around 20% difference..

    Do you often roll your tone controls to zero? very few people do, yet that's what your tone switch is doing, the Gretsch tone switch is referred to by many people as 'the mud switch'...

    This may suit you better:

    http://guitarnuts2.proboards.com/index.cgi?board=modules&action=display&thread=3883

    :D

  13. First thing to check is the pup height.

    In such an old guitar it's very possible all three pickups are identical, ie not calibrated to their positions (bridge pickups are usually wound hotter to account for smaller string movement) if thats the case, the pups height differences would need to be greater than usual to get equal output.

  14. is this because logarithmic pots dont work as tone pots, or does it sound like a botched wiring job?

    Any pot of the right value will work, whether it's log, linear, anti log ect. that's only the taper, the max and min values will be the same so pos. 10 and 0 will be the same. ie it's a botched wiring job :D

  15. Perfect :D

    If your killswitch is NO (normally open, push to connect contacts) connect one lug to the left lug of either vol pot or lug 8 of the 5 way (whichever is more convenient, they are electrically identical)

    Or If your killswitch is NC (normally closed, push to disconnect contacts) disconnect the wire from middle lug of master vol, connect it to a killswitch lug, connect other killswitch lug to the middle lug of master vol.

    A NO switch is preferable, it will earth the signal and be as silent as turning the vol. to zero, the NC switch will be as noisy as an unplugged lead, which can be alright for a momentary killswitch but not for total silence, say, between sets :D

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