# Boss EH-2 enhancer yay or nay?



## Clemenstein (Sep 5, 2014)

My friend had this pedal back in the day and I fell in love with it. Now I am looking for one...anyone have one and like it??? I wanted to post in the for sale / wanted section but I'm guessing I need a number of post count before I can post in there.


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## mhammer (Nov 30, 2007)

Enhancer pedals like the EH-2 are one of those things, much like compressors, that can often be undetectable to those who don't know how to use them. "Is this thing even_ on_?" is a regular comment for both compressors and "exciter" pedals.

They work in a variety of ways, but most often by separating the highs in the input signal, and boosting them. A frequent technique is to clip the highs in order to generate even more harmonic content, which is then blended back in with a mix control of some sort. Another technique - pioneered by Aphex - is to use a sort of VCA, whose input consists of the very same signal it is being controlled by. Think of it like a variation on a ring modulator. This results in a doubling of whatever is in the audio input signal. And since that signal is only the highs, you end up with a goosing of the harmonics of everything in the guitar.

The trouble with this is that a) you actually need to have some highs in the original signal to begin with, and b) your amplification/playback system has to be able to reproduce highs. So, small wonder that such effects sound more audible, and more pleasing when used with acoustic instruments on studio monitors, than they do on Strats going into smaller Fender amps, and much better on those than on Les Pauls going into Orange amps with 4x12 stacks.

http://www.freeinfosociety.com/media/images/4077.png

Let's take a look at it. The EH-2 uses a fairly standard state-variable filter, formed by IC4A/6A/6B - the exact same thing you find in a Mu-tron/Q-Tron - and taps the highpass output of it. IC5 is a dual VCA chip. IC2AB and IC1B forms an envelope follower that drives IC5. Since anything that boosts high end is also going to boost input noise/hiss, leaving that boost on all the time will be problematic. So what the EH-2 does is use that envelope follower to essentially "turn on" the VCA only when the input signal is hot enough to justify it. Stop playing and the VCA goes off, behaving largely like a noise gate, but only for the boosted top end, leaving the rest of the guitar signal unaffected.

I don't know what sort of method they use, but there is an Aphex 1403 Exciter pedal. There is also the DOD "Edge", which is a one-knobber. I can't speak to how decent or different they sound, relative to the EH-2. But they do represent an alternative.

Another rather counter-intuitive alternative are acoustic simulator pedals, since part of what they do is also to goose the highs. Try out something like an AC-2 and see if that brings you any closer to what you want. They tend to be a little more available on the 2nd hand market than EH-2 units. Behringer makes a clone of them.


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## Clemenstein (Sep 5, 2014)

Behringer spectrum enhancer se200?


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## mhammer (Nov 30, 2007)

Nah. Not the same thing. It's a clone of the old Boss Spectrum, which was a quasi-parametric section. It doesn't add any highs, just boosts what you have already.


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## Clemenstein (Sep 5, 2014)

Did you mean Behringer makes a clone of the AC-2 or EH-2?


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## mhammer (Nov 30, 2007)

Bloody tablet!! Meant to hit Reply and hit Dislike to your post. I gotta get a bigger screen.

Behringer makes an AC-2 clone. I have one. A little hissy.


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