3 ms·

Jfets are used a lot in guitar pedals (j201, 2n5457, 2sk30a, ...). Unlike MOSFET they only need one gate resistor (10M gate to ground) in a input buffer configu

by dvh 3y ago

Jfets are used a lot in guitar pedals (j201, 2n5457, 2sk30a, ...). Unlike MOSFET they only need one gate resistor (10M gate to ground) in a input buffer configuration. The drain and source resistors are same as MOSFETs.

midoridensha 3y ago
I feel like guitar pedals are obsolete because of modeling amps now. Why bother messing around with a bunch of separate pedals with 9V batteries and interconnect cables when you can just program the effects you want all in software (using your phone, no less), and instantly switch between completely different configurations (sound profiles) by pressing a button?
- ramenbytes 3y ago
  Because with physical gear I own the means of sound production.
  - pohl 3y ago
    Is that true in some way that is not also true about a Line6 Helix, though, for example?
    - ramenbytes 3y ago
      Yes, with some qualifications. Below, with some edits, is what I originally wrote for the comment you replied to, before scratching it for being too wordy. Some personally compelling reasons for myself as a guitarist: 1) With physical gear, I own the means of sound production. Less so for pedals that integrate closed computing elements into their circuits though, and even less if it has IOT crap (why??). Analog devices are generally best at this aspect. 2) Along those lines, longevity and repairability. Again this applies most strongly to analog pedals. I can keep using a well-designed pedal for decades, and keep it going with occasional repairs and maintenance. Digital modelers (including digital pedals to an extent), not so much, for a number of reasons. 3) In general, physical signal chain elements, particularly analog ones, strike me as more malleable as an end-user. I can do tweak the gain of individual stages, rework the inter-stage EQ and attenuation, etc. with a physical tube amp, and do similar things with analog pedals. Perhaps to a lesser extent with digital pedals too. I'm not aware of a modeling system with comparable flexibility, though I'd be interested in being proven wrong. 4) Some analog stuff, to my limited knowledge, is still difficult to model.
      - midoridensha 3y ago
        >2) Along those lines, longevity and repairability. Why is this an issue? When was the last time you had digital electronics fail, and it wasn't a victim of the early 2000s capacitor plague (in which case, replacing the affected caps fixed it)? "Repairability" is vastly overrated: most electronics don't fail in the first place, and when they do, it's almost always electrolytic caps, and this affects both digital and analog circuits. There's nothing "unrepairable" about a digital circuit: it's not like a logic gate on your CPU is likely to fail. >and even less if it has IOT crap (why??). If you're referring to amps (like Fender Mustang series) that use your phone for the UI, that should be pretty obvious: the phone is an ubiquitous device that you can assume the customer owns, and provides a large touchscreen for controlling the amp remotely. It's not IOT; it's a Bluetooth connection. It's not necessary for using the amp, it's just an option, and a really helpful one when playing with effects settings, and much easier to use than the tiny LCD screen on the amp plus its jog wheel. Once the settings are done, you can assign settings to footpedal buttons and never mess with it again. With the 7-button footpedal, for instance, you can easily set it up with 5 different sound profiles you can easily switch between, with the other buttons you can switch between "banks" of 5 effects if you need more for one song/gig.
  - adql 3y ago
    Physical digital ones are a thing
    - ramenbytes 3y ago
      You're right, and you generally have less control over them because of that.
- adql 3y ago
  Decision paralysis is a thing - while having digital multieffect might open you to near-unending combination of effects, exploring within limits of few single function (not neccesarily analog) pedals is less complex. Also some say some quirks of analog designs are hard to replicate in simulation althought I haven't seen double blind tests of that so I'm mildly skeptical of that
squarefoot 3y ago
True, and they work remarkably well as preamps. Only problem is that they're becoming scarce, at least in THT case, and a lot of people has been burned by online sellers who sent them relabeled BJTs. To my knowledge, J201 and many 2SK* low noise ones haven't been manufactured for years, most reliable sellers don't have them in stock anymore, and those sold online by generic sellers are almost invariably either relabeled random ones (if lucky) or the 1st thing they had at hand, which often is a BJT, not even a jFET. However, if you don't need lots of gain a decent preamp can be built around the venerable 2N7000. Yes, that's a MOSFET, definitely not aimed at audio, but it's dirt cheap, available everywhere ...and noisy. But if you keep the gain to reasonable levels it works quite well. Here's some info. http://www.muzique.com/schem/mosfet.htm http://www.muzique.com/schem/mosfet.htm (the entire site is worth bookmarking)

by dvh 3y ago

midoridensha 3y ago

I feel like guitar pedals are obsolete because of modeling amps now. Why bother messing around with a bunch of separate pedals with 9V batteries and interconnect cables when you can just program the effects you want all in software (using your phone, no less), and instantly switch between completely different configurations (sound profiles) by pressing a button?

ramenbytes 3y ago
Because with physical gear I own the means of sound production.
- pohl 3y ago
  Is that true in some way that is not also true about a Line6 Helix, though, for example?
  - ramenbytes 3y ago
    Yes, with some qualifications. Below, with some edits, is what I originally wrote for the comment you replied to, before scratching it for being too wordy. Some personally compelling reasons for myself as a guitarist: 1) With physical gear, I own the means of sound production. Less so for pedals that integrate closed computing elements into their circuits though, and even less if it has IOT crap (why??). Analog devices are generally best at this aspect. 2) Along those lines, longevity and repairability. Again this applies most strongly to analog pedals. I can keep using a well-designed pedal for decades, and keep it going with occasional repairs and maintenance. Digital modelers (including digital pedals to an extent), not so much, for a number of reasons. 3) In general, physical signal chain elements, particularly analog ones, strike me as more malleable as an end-user. I can do tweak the gain of individual stages, rework the inter-stage EQ and attenuation, etc. with a physical tube amp, and do similar things with analog pedals. Perhaps to a lesser extent with digital pedals too. I'm not aware of a modeling system with comparable flexibility, though I'd be interested in being proven wrong. 4) Some analog stuff, to my limited knowledge, is still difficult to model.
    - midoridensha 3y ago
      >2) Along those lines, longevity and repairability. Why is this an issue? When was the last time you had digital electronics fail, and it wasn't a victim of the early 2000s capacitor plague (in which case, replacing the affected caps fixed it)? "Repairability" is vastly overrated: most electronics don't fail in the first place, and when they do, it's almost always electrolytic caps, and this affects both digital and analog circuits. There's nothing "unrepairable" about a digital circuit: it's not like a logic gate on your CPU is likely to fail. >and even less if it has IOT crap (why??). If you're referring to amps (like Fender Mustang series) that use your phone for the UI, that should be pretty obvious: the phone is an ubiquitous device that you can assume the customer owns, and provides a large touchscreen for controlling the amp remotely. It's not IOT; it's a Bluetooth connection. It's not necessary for using the amp, it's just an option, and a really helpful one when playing with effects settings, and much easier to use than the tiny LCD screen on the amp plus its jog wheel. Once the settings are done, you can assign settings to footpedal buttons and never mess with it again. With the 7-button footpedal, for instance, you can easily set it up with 5 different sound profiles you can easily switch between, with the other buttons you can switch between "banks" of 5 effects if you need more for one song/gig.
- adql 3y ago
  Physical digital ones are a thing
  - ramenbytes 3y ago
    You're right, and you generally have less control over them because of that.
adql 3y ago
Decision paralysis is a thing - while having digital multieffect might open you to near-unending combination of effects, exploring within limits of few single function (not neccesarily analog) pedals is less complex. Also some say some quirks of analog designs are hard to replicate in simulation althought I haven't seen double blind tests of that so I'm mildly skeptical of that

squarefoot 3y ago

True, and they work remarkably well as preamps. Only problem is that they're becoming scarce, at least in THT case, and a lot of people has been burned by online sellers who sent them relabeled BJTs. To my knowledge, J201 and many 2SK* low noise ones haven't been manufactured for years, most reliable sellers don't have them in stock anymore, and those sold online by generic sellers are almost invariably either relabeled random ones (if lucky) or the 1st thing they had at hand, which often is a BJT, not even a jFET. However, if you don't need lots of gain a decent preamp can be built around the venerable 2N7000. Yes, that's a MOSFET, definitely not aimed at audio, but it's dirt cheap, available everywhere ...and noisy. But if you keep the gain to reasonable levels it works quite well. Here's some info. http://www.muzique.com/schem/mosfet.htm http://www.muzique.com/schem/mosfet.htm (the entire site is worth bookmarking)