Capacitors

Pete.

“There are 10 kinds of people in the world: those who understand binary, and those who don't.”

Comments

  • nicholaspaulnicholaspaul Posts: 573Member
    Fascinating. I had no idea! I saw a Joe Gore video where he compares various types of cap and concludes that they make no sonic difference whatsoever.
    So ceramics are ok to use, again? Perhaps I should chuck out all my orange drops.
  • MegiMegi Posts: 6,774Member
    I'm certain the article gives spot on advise - too late for me :D as some while ago I bought a box of paper in oil capacitors from a chap in Moscow...
  • nicholaspaulnicholaspaul Posts: 573Member
    Cool I bet you got a good deal, hey?
    I'm happy with the orange drops. If I buy any more I suppose I'll get the ceramics. Too bad they don't make them in prettier colours.
  • DaveBassDaveBass Posts: 3,301Member
    As an electronics engineer who started his career (in the 1970s!) designing professional audio equipment, I can assure you there's no audible difference between different types of capacitor!

    The main two imperfections in capacitors are equivalent series resistance (ESR) and equivalent series inductance (ESL; L being the standard symbol for inductance, as I is used for current). There's a resonance between the capacitance and the ESL but for the sizes of capacitor used in guitars, it'll be in the megahertz region, well above the audible range. This is important for radio frequency design, but not for audio. As far as RF interference pickup is concerned, that's a matter for the active electronics inside effects units and amps, not the guitar. (And it's not difficult to deal with, if you know how and if the boss isn't penny-pinching.)

    Ceramic capacitors do have their own deficiencies, the worst of which is temperature-varying capacitance (depending on the dielectric used). But you'd be hard pressed to detect this, as most guitars are kept at a fairly constant room temperature -- for good reasons! Ceramic capacitors can also be nonlinear (capacitance a function of voltage) but again this isn't a problem at the low voltage levels of guitar electronics.

    There really isn't any audible difference, so just use whatever's to hand.
  • nicholaspaulnicholaspaul Posts: 573Member
    It's great to have an expert on board! Well, seeing as I work better at constant room temperatures too, I'm sure my guitars will be happier!
    All our fears are now safely put to bed, in an induced coma with a DNR notice!
  • MegiMegi Posts: 6,774Member

    Cool I bet you got a good deal, hey?
    I'm happy with the orange drops. If I buy any more I suppose I'll get the ceramics. Too bad they don't make them in prettier colours.

    I can't remember now, but I think I got 20 0.015uF Russian paper in oil capacitors for about £15. The ceramic ones, and even the modern metal film poly ones are certainly a lot cheaper. But still, it was kind of fun to receive a box sent from Moscow, plus they look cool, and of course there's the "mojo" :D

    I have seen ceramic ones that have a blue dipped finish that look quite sexy...
  • Kevin PeatKevin Peat Posts: 2,779Member
    As it happens I recently bought myself a 200 in 1 experimental electronics lab. All largely obsolete stuff now but very interesting nonetheless.

    I was hoping to lift the veil on the mysteries of solid state technology, which is all voodoo to me.

    I've been working through the Dummies Guide, though it is a bit patchy on explanations.

    I'm still uncertain the differences between PNP and NPN transistors, for instance.

    Also circuit diagrams.

    It appears to me that components don't necessarily appear in the order that I would expect considering the flow of electricity - nor do I have much idea where I should put the probes on my multi-tester (no suggestions, other than technical ones please !)

    It seems that the plumbing analogy so used for electricity has its limits. Electricity doesn't actually work anything like a plumbing system.

    I get the impression that - seeing as electricity travels at the speed of light - the direction of flow is merely a theoretical idea and that resistors and diodes work instantaneously and become the sum of their parts - how can resistors work if they are placed after the protected component, for example ? (I am aware that electricity flows from negative to positive btw.)

    Just a hobby to distract me.
  • Kevin PeatKevin Peat Posts: 2,779Member
  • nicholaspaulnicholaspaul Posts: 573Member
    Megi said:

    Cool I bet you got a good deal, hey?
    I'm happy with the orange drops. If I buy any more I suppose I'll get the ceramics. Too bad they don't make them in prettier colours.

    I can't remember now, but I think I got 20 0.015uF Russian paper in oil capacitors for about £15. The ceramic ones, and even the modern metal film poly ones are certainly a lot cheaper. But still, it was kind of fun to receive a box sent from Moscow, plus they look cool, and of course there's the "mojo" :D

    I have seen ceramic ones that have a blue dipped finish that look quite sexy...
    Cor, that is a good deal. I bet the 20 last you a while too.
    Oh yea, its all about the Mojo. Perception is reality:-) no seriously, I'm all about that, as long as it's not illegal, expensive or hurts anyone.

    Oo blue ceramic! Going shopping........
  • nicholaspaulnicholaspaul Posts: 573Member
    edited August 29

    As it happens I recently bought myself a 200 in 1 experimental electronics lab. All largely obsolete stuff now but very interesting nonetheless.

    I was hoping to lift the veil on the mysteries of solid state technology, which is all voodoo to me.

    I've been working through the Dummies Guide, though it is a bit patchy on explanations.

    I'm still uncertain the differences between PNP and NPN transistors, for instance.

    Also circuit diagrams.

    It appears to me that components don't necessarily appear in the order that I would expect considering the flow of electricity - nor do I have much idea where I should put the probes on my multi-tester (no suggestions, other than technical ones please !)

    It seems that the plumbing analogy so used for electricity has its limits. Electricity doesn't actually work anything like a plumbing system.

    I get the impression that - seeing as electricity travels at the speed of light - the direction of flow is merely a theoretical idea and that resistors and diodes work instantaneously and become the sum of their parts - how can resistors work if they are placed after the protected component, for example ? (I am aware that electricity flows from negative to positive btw.)

    Just a hobby to distract me.

    This looks fascinating. I know what you mean about flow. I think electrons go wherever they are connected, rather than in a straight path. Bit weird. Sounds like it would be fin experimenting though. I really don't get electronics...
  • Kevin PeatKevin Peat Posts: 2,779Member
    edited August 31
    OK

    So while wifey was watching some s@*te on TV last night I built myself an oscillator, Morse Code practice thingy.

    It comprised two resistors (one presumes, to protect components) one transistor (to act as an amplifier, a 3v dc supply, a step up transformer (inductor, feedback generator) inducting a small speaker - a switch, a variable resistor and a couple of capacitors (one presumes to clip any variation in feedback current frequency generated from the inductor,)

    I haven't a clue what I've done - only that it all works.

    I don't understand why I didn't just wire the switch, speaker, resistor and variable resistor to the speaker directly. I bet it would have worked the same but I did what The Kit told me to.

    (This experiment was an electronics by numbers project in the kit.)
  • Kevin PeatKevin Peat Posts: 2,779Member
    PS, It set the dog howling at a key moment in the TV program.
  • Kevin PeatKevin Peat Posts: 2,779Member
    OK. Since howling dog moment I did exactly as proposed and wired said speaker directly to battery. I took a risk that it couldn't be damaged by a direct voltage to it.

    Nothing happened. The speaker is OK and one concludes that the cap, transistor, inductor, resistor combo goes to set up an oscillating frequency from a DC battery to the speaker cone.

    My aim eventually is to create an Ibanez Tube Screamer copy that includes some outboard electronics to the kit and looks really Back to the Future and show it to my friends when they come around for dinner.

    I might don a silver moustache and replicate the Chuck Berry moment for them too.
  • MegiMegi Posts: 6,774Member
    Science in action KP - you had a theory, tested it, and adjusted your hypothesis to fit the evidence. And you certainly know how to throw a dinner party. :)
  • nicholaspaulnicholaspaul Posts: 573Member
    Megi said:

    Science in action KP - you had a theory, tested it, and adjusted your hypothesis to fit the evidence. And you certainly know how to throw a dinner party. :)

    I'll bring the wine! That Tube Screamer would at the very least make a much better centrepiece than flowers.
  • Kevin PeatKevin Peat Posts: 2,779Member
    I need to throw a *control* dinner party too. To check out any ... feedback.
  • nicholaspaulnicholaspaul Posts: 573Member
    /* over my head... */
  • Kevin PeatKevin Peat Posts: 2,779Member
    edited September 7
    Well. It was clearly a bad pun because I have to explain it.

    Megi suggested that I'd tested my theory scientifically, in which case I should have run a control test along side it... ie a dinner party without a 'Tube Screamer' present.

    Now, that is just the first part of my carefully crafted gag. The second part involves a clever double entendre; 'feedback', which could be interpreted one of two ways:

    - feedback from my dinner party guests on what they thought of my device

    - feedback from the device itself, it being a fuzz pedal type overdrive thingy.....

    ........................................................

    .....

    ..

    Boom boom !
  • Kevin PeatKevin Peat Posts: 2,779Member
    ...gets coat.
  • nicholaspaulnicholaspaul Posts: 573Member
    Aahhhhhhhh...... that makes sense now. Sorry, me being thick. Or overthinking it. I thought maybe a part was used to control feedback or something.
    Nicely done!
  • Kevin PeatKevin Peat Posts: 2,779Member
    Laugh, dammit !
  • MegiMegi Posts: 6,774Member
    edited September 9
    Bob Monkhouse: "They all laughed when I said I was going to be a comedian. Well, they're not laughing now." :D
  • nicholaspaulnicholaspaul Posts: 573Member
    Megi said:

    Bob Monkhouse: "They all laughed when I said I was going to be a comedian. Well, they're not laughing now." :D

    Genius!
  • nicholaspaulnicholaspaul Posts: 573Member

    Laugh, dammit !

    Teehee?
Sign In or Register to comment.