Oberheim GM 400 by Chris Bereznay Reposted with permission from Music Gear Review Oberheim GM 400 Rack Multi-Effects Processor High in features, low in price! The key word today in the guitar effects processor industry is "flexibility". At the recent Winter NAMM show the name of the game in this category was "Who Can Build The Most Flexible Multi-Effects Modeling Processor". This usually includes giving a guitarist a floor board, table top or rack unit processor that can either plug directly into a guitar amplifier, headphones, straight into a PA system or recording mixer. Another qualification for entering this game is that it includes multiple configurable effects channels and types, amplifier modeling, miking and cabinet simulation and is compatible via MIDI in / out / thru with any MIDI controller device that can be used to change and switch effects and parameters on the fly. In addition, the public is no longer content with cheap digital effects and has developed an ear for what is "good" so sound quality is also a big consideration when evaluating these units. Coincidentally many manufacturers have jumped into this very popular product line and have begun to offer innovative new products that meet most or all of the requirements listed above. This includes Oberheim and their GM400 Rack Effects Processor. The GM400, which can be found at MusicYo for just $299 is a one rack-space processor that surprisingly fits the bill in this arena and offers a heck of a lot more than you'd expect in a rack unit at this price point. I've always associated the name Oberheim with MIDI and Analog Keyboard / Synthesizer products. It's apparent with the GM400, though, that our friends at Oberheim flexed some of their engineering muscle and put out a really competitive product at a real value price point. Over the course of a week or so, we played through the GM400 with various guitars and utilized it in several different scenarios to see if there was anything it couldn't do. Our American Texas Special Strat sounded sweet on the cleaner settings and those awesome Pink Floyd-esque delays, not to mention the SRV inspired settings, but really began to growl when we kicked in the Seymour Duncan Pearly Gates double humbucker in the bridge. The myriad of distortion settings on the GM400 are quite impressive and with the Seymour Duncan dual humbucker the GM400 screamed. We also tried a Kramer Baretta Infinity Sustainer, Kramer Pacer FT202S, LTD MH-300 and an Ibanez RG570 through the GM400 and once again it came through with flying colors. Each guitar brought it's own unique coloration to the tone and it's important to note that the Pacer, one part of a $179 beginners rig from MusicYo, sounded strikingly similar to my Ibanez RG570 - a $600 guitar. Then again, years of loud music may have dulled my senses - at least that's what I tell my wife when she accuses me of "selective hearing." As far as output devices go, we tested the unit through a Yamaha DG80-210A amplifier, a Marshall VS65R and also as a stereo direct line-in to our 1200 Watt Mackie 808S PPM Professional Powered Mixer. Although sending this unit straight to a guitar amplifier has a certain expected tonal characteristic influenced by the amp itself, we were unexpectedly blown away running it into the Mackie powered mixer and through two giant cabs. This is where you can really tell the quality of the effects and the signal. The entire frequency range was exploited. Effects that take advantage of the lower ranges of the scale were pounding our skulls with strong, clean bass tones and the high end of the register was crystal clear. Even through a less expensive PA rig like the Electar 4 ( $179 ) from MusicYo, the unit was clean as can be. Our guess was the excellent tone we were hearing was a direct result of the professional quality sampling rate, S/N ratio and bandwidth. Then again, any time you crank a guitar through a 1200 watt PA system, the hair on the back of your neck is going to stand up. Last but not least, we began fiddling with the amp and bass modeling simulation controls and settings while laying down tracks in Cakewalk Pro Audio 9 on our studio PC. We had a blast writing some tunes with this unit and the clean signal was a joy to work with in Cakewalk. I'm a sucker for a big ballsy guitar sound, so I'll admit I spent most of my time on the "hot valve" setting with the 4x12 cab selected and a basic rock and roll beat driving the tune. There are also several other settings in these screens that let you adjust the nuances of the sound. It's probably possible to simulate anything from a Fender Tweed to a Marshall Stack or a Mesa Boogie Dual Rectifier but there's not a lot of "instruction" in the manual for "how to do it". The manual is more of a reference. Finally, the only thing we found missing that would have been the icing on the cake is some sort of microphone placement modeling for the guitar and bass amplifier simulations. This unit has everything but. Some other units on the market provide you with the capability of adjusting where the microphone would be if you were miking the actual amp you are trying to simulate. Common settings are head on, off axis, etc. This feature may be something that's available in the higher end units of the line like the GM1000, but we haven't had the chance to get our hands on them yet. For a processor that offers so much functionality, the trick to getting the most out of the GM400 is getting comfortable with the interface and learning by experimentation. It's been my experience that getting the most out of such feature laden units as this is going to present you with some type of learning curve. The Oberheim GM400 had me scratching my head a few times in the first few hours I was playing with the unit. Some of the processes by which you back out of menus, change settings and save and exit can be a little confusing at first. Call me a dummy but it just wasn't that intuitive. The manual does an OK job of explaining the process, but numb-skulls like me could probably use a brief tutorial of sorts. There is so much to access and play with here it will take you a while to explore the capabilities of the whole unit. It's not as easy as twisting knobs. However, if you're a tweaker, a gear-head or anything similar - you're going to love this unit. Where can you find a rack unit with this many features for the price? Check out the technical specs below for a summarized list of the capabilities of this processor: Technical Specifications Memory: 3 banks x 128 Programs = 384 2 Channel A/D: 18 Bit, 102dB128x Oversampling 2 Channel D/A: 18 Bit, 102dB64x Oversampling Sampling Rate: 44.1KHz Audio Bandwidth: 20Hz - 20KHz (+/- 1dB) S/N Ratio: 100dB THD: 0.007% @ 1KHz, 0dB Effect Groups: Compressor: Compressor, Limiter Distortion: Crunch, Overdrive, Distortion Equalizer: Mono 10-Band Graphic, Stereo Parametric, Guitar Amp EQ Amp Simulator: Guitar, Bass Modulation: Chorus, Flanger, Phaser, Tremolo, Vibrato Delay: Standard, Tap Tempo, Stereo (Tap) Tempo, Multi (parallel) Metronome 1, Metronome 2 Reverb: Reverb, Gate Reverb, Virtual Chamber Special - 1: Wah-Wah, Fade In Special - 2: Pitch Shifter 1, Pitch Shifter 2, 4 Voice Chorus Tuner: Concert Pitch A4: 435 - 445 Hz Tuning Range: A0 - C8 Tuning Accuracy: 1 cent Modes: Chromatic, 4/5/6 String Bass, Standard Guitar, 12-String, Guitar, Open G, Open D, Open Em, Dropped D, Guitar Flat, Guitar Double Flat Display: 2 x 40 LCD Programming Controls: See Front Panel Inputs: 1/4 Mono Instrument, Left (mono) 1/4", Right 1/4" Outputs: Headphones, Left (mono) 1/4", Right 1/4" MIDI: IN, OUT, THRU Pedals: 15 Pin FC-3000 Foot Controller (Optional), Tap, Hold Power: 115V AC, Adapter Included Bottom Line: The Oberheim GM400 is a great processor for the money. Although it's not as user friendly as some of the other units out there, it can really end up being more flexible once you learn how to use it. The presets sound pretty good, but we found some of them to vary greatly depending on the type of guitar you are using - which is what we would expect. Don't fret though ( no pun intended ), you've got 3 banks of 128 sounds ( 384 total ) you can play with and save to! In summary, we think this unit can compete with the more "hyped-up" models that are out there. It's competitive from a price standpoint and it sounds really good - not cheap like some of the junk we've run into over the years. If you're the kind that enjoys tweaking to get the perfect sound for a particular song or you're just looking for the perfect tone for a track you're recording - check out the GM400 from Oberheim. The unit is available from MusicYo on the web. Check them out at the link below! 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