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The AcH 104 is the original quality pre-amp designed with the acoustic musician in mind. Ideally, the best way to duplicate the acoustic sound of your instrument is to use a microphone. Considering the volume levels of todays concerts and club dates, it is increasingly more difficult to get the sound of an acoustic instrument to match those levels with just a microphone. Having only a microphone also creates problems with monitors because feedback runs rampant when you try to turn up the instrument in the monitors. Obviously a transducer or pick-up is the next step. Most musicians are not pleased with the sound the get out of the pick-up. However, the pick-up allows for greater volume level with a consistent level, and more flexibility in stage monitors. So what is the solution? Use both!  Neither is adequate on its own, but the two together produce wonderful results.

I know, maybe you've been doing this for years. The many batteries, patch cords and floor boxes involved might not be worth the trouble. The AcH 104 solves these problems. It is a 110v single rack mount unit that accepts a stereo cord from your instrument. Within your instrument is a pick-up of your choice and a miniature condenser microphone. The unit powers the mic via the stereo cord. The pick-up is tip and the mic is sleeve, which allows the unit to be used with a standard cord and pick-up only if desired. Many of today's mini condenser microphones can be adapted to be used with this system. This type of set up is adaptable with almost any acoustic instrument. To give an example, an upright bass has a number of pick-ups available. Use one with a mic mounted on or in the bass and the AcH 104 provides a working combination.

            The unit is basically a two channel mixer with a few added extras. The signals from the instrument are sent to a MIC and PICKUP INPUT control. The mic signal is sent through an EQ section with hi/low shelving and boost/cut controls. The pick-up signal goes through an EQ section with hi/low shelving and two points of selectable parametric EQ, all with boost/cut control. Each signal, MIC and PICKUP, has an output control as well.   The key to this unit is that the signals can be sent directly out of the unit to the mix board or to your amp as separate signals. The signals can also be mixed with the aid of headphones and sent via the COMBINED OUTPUT as one signal to your amp and/or to the mix board. There is a balanced and unbalanced output for all three signals, MIC, PICKUP and COMBINED. Signals are converted to balanced by Jensen transformers within the unit. All six outputs can be used at once or in any combination desired. The three Jensen ground isolated transformers eliminate the need for external direct boxes. This allows you to leave another battery and patch cord behind.

            There are a number of other features. Patch points on each post signal allows you to add effects to each signal. For example, more EQ on the MIC, a delay unit on the PICKUP, and a volume pedal on the COMBINED. There is also an adjustable output for a tuner. Headphone jack and volume control allow you to listen to the tones and effects of each signal and the mix of the PICKUP and MIC. Finally, a mute switch turns off all output signals except to the tuner and headphones. This allows for silent tuning while on stage and presetting the mix to be sent through the COMBINED output.

So what are the advantages of the AcH 104?

            First of all, this system gives the musician a greater degree of control over the sound of the acoustic instrument through the amplification of your choice. Here are a few situations, there are many!  In a small club situation, all you may have to work with is the amp you bring with you. You may choose to send just the COMBINED output to your amp. You and the audience will hear the same sound. A good mix of the MIC and PICKUP will surely improve the sound of your performance. Or you may choose to plug directly to the house PA system without the use of your amp and send the COMBINED through the mains. Listen to the mix of the MIC and PICKUP through the headphones, then listen through the house speakers and make your final adjustments.

            If you are in a larger stage situation with stage monitors and a house mix, the combinations are many. An example may be that the house engineer is unfamiliar with the sound you are looking for. So again, you put on the headphones, dial a great mix of the MIC and PICKUP and send the mix out to the house board through the COMBINED output. But the stage volume is great enough that the COMBINED mix you sent to the house is causing feedback when it is turned up in the monitors. Simply send the PICKUP output to the house board as well. This will assure you that the audience is hearing what you desire and the monitor feedback problem has been solved by using only the PICKUP in the monitors. Make sure the engineer understands that he should not use the PICKUP signal in the house mix or the COMBINED signal in the monitor mix. If there is a separate monitor board and monitors are being controlled through the stage board, send the COMBINED to the house console and PICKUP to the stage monitor board. When working with a familiar audio engineer, you both would probably agree that the flexibility of using the PICKUP and the MIC separately will produce quality results. This allows your house engineer to fine tune the mix of the two, considering house conditions. If you are in the studio, the engineer may want to record your pickup sound as well as using a studio quality microphone to get your sound. You would have the ability to send the engineer a more pleasing COMBINED sound for your pickup instead of just the pickup sound.

            The next advantage is that the system uses a ôstereoö cord which carries the MIC and PICKUP signal from your instrument to the unit. Simply have a stereo end pin jack (TRS phono type) mounted in your instrument. There are many ways to mount the jack in fiddles, upright basses, banjos, etc.. In a guitar, it is your end pin strap holder. All you need is a three conductor cable, two leads and a shield, I make great cables if you need one.  The third advantage is this system also powers the high impedance mic in your instrument. So there are no more batteries or on/off switches to deal with. The freedom that comes from not having to stand in front of a mic while having the consistency of a mic sound that is worth the effort. It  makes your stage presentation look a whole lot better.

            Finally, the AcH 104 is a professional rack mount unit. By using it, you will no longer have to contend with toy boxes and their batteries and patch cords. If you mount the AcH 104 in a rack, your effects units can be always connected, allowing for quick and simple set up. Just plug your instrument cord in the front and send the outputs where desired.


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