Behringer AM100 Acoustic Modeller - review

[Mark Hammer]

I tried one of these out today and liked it enough to buy it.  $35 Canadian.

Not a bad little unit for the money but like anything in the enhancer/exciter class of effects, if you don't have a piezo or other tweeter in your amp, you will be less impressed.  I tried it out with a Schecter dual HB guitar into a Genz-Benz acoustic amp.  Sounded great.  I found myself able to nail a variety of very nice tones including Tuck Andress' almost acoustic sound from his Bartolini-equipped archtop that I'm quite partial to.  Brought it home and plugged my Turser Tele with homebrew pickups into it and into my Princeton.  Not nearly as impressive.  Part I suppose is the degree of hum-immunity, and another part is the absence of a tweeter in my amp.  I have an add-on piezo tweeter somewhere in the garage I can wire up, so I'll see if that makes a notable difference if I can find the time...and the tweeter.

This is an all-analog unit that I, naturally, had to take apart once I had it in my mitts.  Semiconductors are a pair of surface mount TL064's, a couple of SMT transistors of unidentified type, and a pair of CMOS chips for switching (4066/4052).

Interesting construction.  The box is what I assume to be a standard white plastic for all boxes in the series, with brown paint on it.  The heaviest part of it is a metal baseplate underneath that seems to be there to add some distracting heft to it and make it feel solid, as well as keep it from flipping over if you move .  It's weird seeing the dollar store implementation of some things we've seen in higher-priced pedals.  The battery compartment operates in a similar manner to the Line 6 Tone Core compartment, with two side buttons you push in simultaneously to pop the lid.  In this case it is ridiculously cheap plastic, although I'm not sure what else to expect in a $35 bubble packaged pedal to be sold hanging from a hook like packages of AA batteries.  The pots seem to be no better or worse than those found in most Boss pedals or Rocktek pedals, and the momentary switch is a tiny thing.  The PCB is double sided with all semiconductors, resistors and small caps on the underside, and the switches, caps, and pots on the top side.  Don't ask me to reverse engineer it - my eyes can't follow a circuit that miniaturized, especially when it's double sided.

This sucker eats current for breakfast lunch and supper (25ma current draw).  It is also noisy. At least it is at home.  I don't recall any noteworthy hiss at the store, but that may have been due to the Schecter's electronics, and the fact that another guy in the store was busy being EVH in his mind at Saturday music-store volume.  I suspect the noise is more due to the use of TL064's to gain some lost ground on current consumption than due to the plastic chassis.  If one were diligent, had hands that did not shake, a sharp solder tip, and planned to power it with a wallwart, I suspect that replacing the TL064's with TL074's might help a bit.  Good range of control, with lots of different possible tones from the Enhance and Resonance controls, and probably as much control as the Boss AC-2, though I could not say how they compare in terms of noise.  The noise itself is contingent on how you set the Enhance control.  Setting it higher than 12:00 tended to be a little too hissy for my tastes at home.  I forget what I set it to at the store, but I seem to recall diming it and hearing no issues.  At the very least, noise performance saeems to vary with context.

Of course the question that arises is whether this is worth buying, as compared to building your own unit, such as the Woody thing I made before pedals like this became so cheap, or the layout for the AC-2 from Christian Briere (I think).  I'd say so.  Though I haven't built or heard Oliver Alex's improved version of my Woody circuit to compare, when you factor in the time savings, and the fact that the parts would end up costing $15-20 anyways, $35 is a decent price to pay.  Certainly no one else has anything comparable in this type of pedal for this type of price.  What I find funny is that the parts count for the AM100 are likely 2-3 times as high as for the Tube Screamer clone available in the pedal series, yet the TS clone is $10 higher in list price.

[finkfloyd]

Hi, thanks for the review I was comsidering getting one of these as they are so cheap, 4 days ago I ordered the UF-100 Flanger to try out, as it was so cheap

I havent recieved it yet though.

I also hear good things about the chorus they do, and also soon there will be the digital delay and reverb pedals out

[MartyMart]

I also found mine to be a "little" noisey, but I thought that one of the settings (Jumbo?)
was really quite good !
Plugged into a desk for a bit more "EQ'ing" can release good results.
and for £14.99 ...... COME ON !!
BTW it sounds more "real" than my AC-2 clone   
Which took me a good 10 hours to build/de-bug and cost more to make !!

MM

[j.frad]

I tried one in a shop recently, I thought it was not bad, and I went back there a couple days later and A/B-ed it against the Boss AC-2, with a tele and a strat into a little fender solid state amp, that's when I reallized the Boss so much better! I will never get the behringer version because the AC-2 is IMPRESSIVE!

With the AM 100 you're more like:yeah, ok, pretty close, not bad...
with the AC-2 you're more like: that's what I'm talking about! yeah!!!!!!

Well that's what I felt like...

[Mark Hammer]

I looked over the schem for the AC-2 last night, and compared it against what I saw in the AM100.  Here's what I found:

• AC-2: 8 op-amps coming from four M5218L duals; AM100: 8 op-amps coming from a pair of TL064's
• AC-2: uses CD4052 and CD4066 for switching of filter modes; AM100: 4066 and 4052 also on-board
• AC-2: uses dual-ganged pot for "top" control and single pot for "body"; AM100: dual-ganged pot for "enhance" top-end control, and single pot for "resonance" control that controls bottom
• AC-2: four position guitar-type switch; AM100: same

This is not enough to say it is the same circuit, but is it possible that the AM-100 is an AC-2 clone with a few cosmetic changes that change the sound a bit?  Atr the very least, the 5218's are a better (and less noisy) op-amp, relative to the TL064's.

[MartyMart]

That's a shocking comparison !  would seem to be quite "close" to me ....
In a metal "box" it would easily be worth 40/50 £'s ... so £14.99 ....

MM.

[Steben]

I looked over the schem for the AC-2 last night, and compared it against what I saw in the AM100.  Here's what I found:

• AC-2: 8 op-amps coming from four M5218L duals; AM100: 8 op-amps coming from a pair of TL064's
• AC-2: uses CD4052 and CD4066 for switching of filter modes; AM100: 4066 and 4052 also on-board
• AC-2: uses dual-ganged pot for "top" control and single pot for "body"; AM100: dual-ganged pot for "enhance" top-end control, and single pot for "resonance" control that controls bottom
• AC-2: four position guitar-type switch; AM100: same

This is not enough to say it is the same circuit, but is it possible that the AM-100 is an AC-2 clone with a few cosmetic changes that change the sound a bit?  Atr the very least, the 5218's are a better (and less noisy) op-amp, relative to the TL064's.

And again I'm confronted with my love for low-noise, low-power LinCMOS opamps that you can stick in any FX for the better....