Boss EH-2

Discussion in 'Effects, Pedals, Strings & Things' started by Moe45673, Jul 2, 2006.

  1. Moe45673

    Moe45673 Member

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    This pedal's gotten good reviews from HC and BossArea. It also seems to go for dirt cheap and looks like a hidden gem.

    Can it do things my compressor and EQ pedal combined cannot? Is it worth putting in my rig? Does it sacrifice dynamics for restoring tone? Any info is appreciated!
     
  2. Nitefly182

    Nitefly182 Member

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    It just replaces some lost high end and adds some sparkle. Contrary to popular belief you will hear a difference right away.
     
  3. svanangen

    svanangen Member

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    In my opinion it totally and falt out blows! It steals some of your original tone and then lets you add some very artificial sounding presence. I own it and never use it but I will keep it because I bet that these little gadgets won't always go for dirt cheap...
     
  4. theelectic

    theelectic Guest

    IIRC from a technical standpoint, it's an expander that works on the high frequencies. Sort of like a reverse compressor. Instead of compressing highs, it expands them, making them pop out more. How is this different from a regular EQ? Well the EH-2 is envelope controlled - hit a string harder and the effect comes on stronger.

    So no, you can't put a compressor and EQ together to replicate the EH-2.
     
  5. Moe45673

    Moe45673 Member

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    Thanks! I think I'll spring for one of these....
     
  6. John Phillips

    John Phillips Member

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    That was my impression too - turn on for instant Thin Tone.
     
  7. TieDyedDevil

    TieDyedDevil Member

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    I've never found a schematic, but I believe that thelectic's analysis is close, if not entirely correct. I think there might be a bit of harmonic generation also happening on the high frequencies, kind of like an enhancer. But the EH-2 definitely has that expansion thing going on.

    The EH-2 is an unfairly maligned, much misunderstood pedal. I held on to mine for quite a while. The secret is that you have to use a very dynamic (as in lots of volume range) playing style to bring out the best of the EH-2. It's one of the few pedals that doesn't make "something out of nothing"... you have to literally "play" the pedal. It worked for me, I think, mainly because I play fingerstyle; my attack ranges from barely brushing the strings with my fingertips to popping them like a bass player.

    What happens when you give the EH-2 a lot of dynamic range to work with is that it exaggerates your playing dynamics. Play softly and the guitar sounds normal. Play hard and the guitar doesn't just sound louder, the sound *leaps* out at you. It's a very dramatic effect when played well.

    But, yah, if your playing dynamics are mostly constant then the EH-2 will either sound like it's sucking tone (not excessively, just the normal Boss buffer lossage) or thinning out your sound, depending upon how you set the controls.
     
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  8. theelectic

    theelectic Guest

    Schem is here, let's walk our way through it:

    [​IMG]

    In the bypass mode, the guitar signal goes to a FET source follower (no gain), then to an inverting stage with a gain of 1, then into a summing amp (mixer) also with a gain of 1.

    In the effect "ON" mode, the dry signal is still present; it's mixed in at the last stage. The source follower feeds the "wet" side, where it's split into two paths. Path A goes to a variable frequency filter (controlled by the FREQ knob) which feeds the audio input of a VCA (pin 4). Path B goes to a variable sensitivity rectifier which feeds the control input of a VCA (pin 3). So the input signal is being filtered and EQ'd and put through a VCA.

    The output of the VCA (pin 2) feeds an emitter follower (buffer). The output of the buffer goes to another inverting gain of 1 stage. The output of the two buffers is variable from the MIX knob. By adjusting the MIX knob, some frequency cancellation takes place since the signals are out of phase. The output of the MIX knob goes to the final output mixer, where it's mixed in with the original dry signal. From there it goes on to the amp.

    The EQ stage seems to be a simple gyrator based high EQ, like a graphic EQ - someone correct me if I'm wrong here since recognizing EQs is not my strong suit - centered around 2kHz.
     
  9. John Phillips

    John Phillips Member

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    That's the exact opposite of what I found - and I play exclusively with fingers. I use dynamics all the way from barely touching the strings to thumping them so hard that I can't play light strings because of tuning problems.

    My experience with the EH-2 was that the harder and more dynamically you play, the worse it sounded. I bought it because I wanted something to enhance the subtleties of playing dynamics and touch, but found it did the exact opposite. The sound when played hard was so uncomfortably artificial that I was always holding back from playing how I wanted in an attempt to stop it sounding nasty, and ended up with far less dynamics and variation. I could hear the out-of-phase component quite clearly too, which always sounds thin to me.

    In case you're wondering, I don't like compressors much either BTW :).
     
  10. TieDyedDevil

    TieDyedDevil Member

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    Cool. Thank you!

    I don't recognize that filter topology. I'll take your word for it...

    The MIX knob is being used as a level and phase control. The ends are fed by signals of opposite phase. When the wiper is in the middle the signals cancel and you get zero output. Move the wiper toward one end or the other and you get an increasing amount of in-phase or out-of-phase signal to mix with the original.

    I can't quite make out the nomenclature on the VCA. Is that a NE570?


    And you're right, there's no distortion generator. At least not intentionally so...



    Thanks again for the schematic.
     
  11. TieDyedDevil

    TieDyedDevil Member

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    Well that's interesting: similar playing approach, same pedal, totally different conclusions. OTOH, that's not so unusual `round these parts, is it? ;)

    To be fair, I didn't like my EH-2 enough to hang onto it. I didn't have a difficult time getting an acceptable sound out of it; IIRC I preferred the '-' side of the mix control and found that the freq control setting was critical but easy to set. OTOH there was a very narrow range of settings that I'd consider acceptable. IME this is true of a lot of Boss pedals.

    I agree with you about the artificiality of the sound, and that's ultimately why I sold the EH-2. Like you, I wanted something to provide a more subtle enhancement of playing dynamics. I found myself "playing" the EH-2. I wasn't annoyed by the sound like you were; maybe just a difference in settings or expectations. It's an interesting effect and I found some good uses for it, but it's not one of those effects (like reverb, for me) that I'd want to incorporate on a regular basis.

    I still think there's some promise in an expander-type device...
     

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