Switching options in an amp vs tone

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by CubanB, May 2, 2015.

  1. CubanB

    CubanB Member

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    This maybe a controversial topic for some, one of those polarising issues that TGP seems to focus on. The quest for "tone" etc. Things that are hard to compare in tests without a lot of work etc.

    In most cases, vintage is usually preferred. Simpler circuits, less options etc. More pure and unaltered.

    I was thinking about this earlier and wanted to ask if there's ever been any hard evidence of these things, both in tube amps and also pedals (as a sidenote).. where if you have one circuit completely pure vs another with lots of switching options. It could be a tubescreamer with 3 switches for different options, or especially.. an amp. Things like effect loops, master volumes, channel switching, for some even this is too much and robs tone.

    Let's imagine an amp, that has switchable "voices" for the cathodes of various preamp stages. A 3 way switch like "fat, bright, full", with 3 different cathode bypass caps and resistors. Or switchable negative feedback resistors, switchable coupling caps. Switchable tonestack values for the slope resistor, or the bass cap. A switch for tube rectifier vs diodes. Some sort of chameleon amp with a whole bunch of options. Something similar to Mesa Boogie's philosophy.

    If you experimented with all of these types of switches and found a setting, and then removed all switching, so that these values were locked in. And then back to backed the amps in a comparison? How much tone difference would one expect? A subtle difference or a major difference? Would it be as simple as altering the EQ a little bit to compensate, or would one amp be more alive than the other?

    Just wondering people's thoughts.
     
  2. diagrammatiks

    diagrammatiks Member

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    There shouldn't be any difference if both amps are well built and well designed.
     
  3. EFK

    EFK Supporting Member

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    +1.

    The only tangible difference I can see is that with excess switches and controls, many people spend more time fiddling as opposed to playing.

    :hide2
     
  4. teemuk

    teemuk Member

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    ^ This.

    In addition, some amplifiers have controls designed to provide a lot of range in adjustment and a large tonal variation throughout the dial, even when extreme settings (or just certain settings) wouldn't really provide all that great tones.

    ...That instead of controls that sound good on virtually every setting, until you realize it's because the range of theur adjustment is so narrow that the controls seem to have almost no effect at all and sound pretty much the same at both extremes and on "12 o'clock".
     
  5. xtian

    xtian Member

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    The Mesa Mark IV is a good example of TOO much. The controls are interactive, and small changes to one can cascade. I spent WAY too much time trying to adjust the tone every time I moved the rig.

    The JCM 800 2203 is dead simple, with far simpler controls, yet a great variety of sounds with the Low and High (additional gain stage) inputs. No switches (although I did throw in a cathode bypass switch on mine ;)

    But I agree that lots of switching options can be added without detrimentally affecting the tone of the original circuit, if the lead dress is done proper.
     
  6. CubanB

    CubanB Member

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    Interesting.

    This was the main disadvantage I didn't mention in the OP, but for me this has never really been a problem.

    If this is the biggest downside it's very good news, other than the fact that it makes it tempting to have switches everywhere that creates an ugly or cluttered look.

    Thanks guys.
     
  7. Silent Sound

    Silent Sound Member

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    I'm a pure signal path fan, but don't have a problem with switches. In fact, there are lots of novel ways of contoling the tone of an amp by switching components in and out of a circuit. Look at the DC30 for an example of how you can switch out various coupling caps that are needed to filter DC current to double as a means of controlling bass.

    My issue with overly complex amps is amps that have too many unnecessary features. I'm talking about things like effects loops, tone stacks, and spring reverb circuits. Now, I'm not saying these are always bad, and in fact they can really improve an amp if done correctly. But they do effect tone and cause some level of compromise.

    To me, what's more important than switches, dials, and other features, is how each of the stages within an amp react to each other. You can make an amp with no controls that sounds bad. Or you can make an amp with 100 switches that sounds great. But generally speaking, if I can make an amp sound great with one tone knob instead of three, I'll build it with just the one. It's the KISS principle. Besides, I've discovered that on every amp I own, I'll play around with the knobs the first few times I play it, but eventually find the setting I like best, and will likely never touch it again.
     
  8. axpro

    axpro Member

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    I like simple designs, and build them whenever i build something, it's a personal preference.

    I think the issue is not with "Added features" Channel switching, alternate values that can be switched in, etc.

    I think the issue tends to be "Quality" If you are building the item yourself, and you care about "tone" subjective as it may be. You can add whatever you want, and you will pay for it one way or another... Adding more features to an amp may mean adjusting budgets (and using lower quality parts) Or having a cramped chassis (and "paying" by having noise issues due to wire placement/component placement)

    I have built a lot of circuits out of leftover piles of stuff, and a few out of carefully ordered parts... The amps i built where i had a goal, worked towards it and bought the correct parts to do it always turned out better than the amps I decided to add switchable values, etc from my parts bin.

    Nothing wrong with experimenting, I am doing it now with a trainwreck express type build in a "work chassis" i have used a hundred times... but if/when i decide if I love it and want a "good one" I will be sourcing quality parts and building it EXACTLY as i want it.

    To go to the extreme, A co worker of mine once built a marshall 2204 clone, roughed in the tone controls and worked out the PERFECT settings... then measured the values and replaced all the pots with resistors... Because that was the sound he was after... the amp only had one knob for master volume. NO ADDED FEATURES lol.
     
  9. Tony Bones

    Tony Bones Member

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    There's something to be said for short, neat signal paths. Running wires out to the panel and back, the signal can pick up noise. Possibly not a big deal if done carefully.
     
  10. pdf64

    pdf64 Member

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    Switching the bypass arrangement of a cathode should be ok (as it's fairly low impedance), but excessive wiring runs in high impedance circuits (eg plate - grid) may be liable to parasitic capacitance creating unforeseen effects, eg feedback loops and other unintentional coupling between various parts of the circuit.
    Good lead dress may be able to help mitigate the issue, but it may be difficult to be sure that it's been eliminated?
     
  11. donnyjaguar

    donnyjaguar Member

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    I use different tone settings depending on the volume I play at so I don't think fixed settings would work.

    Like hi-fi equipment, systems with too many controls generally sound a bit sh*tty.
     

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