As I look back on my personal guitar playing history, I realize that I have grown up in a guitar amplifier world that has always taught that "bigger and louder" is "better". Let’s face it, everyone wants a Marshall Stack that will produce a sonic wall of sound that would peel the paint in their practice space. Companies like Marshall and Mesa Boogie have led the way in large powerful amplifiers, and in the process they have created signature sounds for many artists. Even so, there is a growing trend in the guitar amplification. Some players seem to be trading in their monster setups for smaller systems. These are typically single cabinet designs with only one or two low wattage speakers. The reason is really pretty simple - it is easier to drive enough wattage through a smaller cabinet and have it sound good than it is a larger one.

I decided a long time ago that I wanted to go this route with my guitar rack. Unfortunately, this posed some unique problems that I had to overcome. First, I did not want pay the big dollars to buy a "high end" low wattage guitar amplifier to run my custom "Tone-Tools" cabinet. I decided that I would rather run my rack off of a clean low wattage power amp. Since most low wattage power amps are built for studio monitors, they generally are designed for four ohm loads. Most guitar speakers however are eight to sixteen ohm which left me with extremely limited options with the handful that are four ohm. To solve this problem, I did some research and came up with the D-75A power amp from Crown.

"D-75A" Amplifier by Crown


Bass guitar players have been using power amps to drive their bass cabinets for years now. This led me to wonder why guitar players did not do the same thing. I quickly realized it was because companies that build power amplifiers do not target the guitar players because of the vast (and confusing!) array of heads and combo units on the market today. I decided that I was going to go against the grain, and try to run my guitar rack through a small power amplifier and let my ears decide.

Crown has been producing high quality, professional power amps for decades. They are regarded by many professionals as the industry leader in power amplifier technology, and their power amps have been used by countless professional bands and studios, as well as broadcast facilities. Their amps are built to last and perform. As an aside, I still have a very old Crown power amp called the "Power Base 2" that is still going strong!

The D-75A is a dual channel power amp, in a very practical one space rack mount chassis. Weighing in at less than 10 pounds, it will not add very much weight to your rack at all. The design of the front panel and controls is very simple, which may lead you to believe it is not a high tech piece of equipment. On this you could not be more wrong. All the fancy bells and whistles are tucked away inside the sturdy road rugged chassis, including the features that I really needed for my project.




· Automatic Ohm Switching allows the D-75A to sense the load of the speaker you are plugged into, and set the power output to the proper level. It handles 16, 8, and 4 ohm loads with ease. This feature takes all the guess work out of the equation. Just plug in and play with confidence that you are not going to ruin you new vintage speaker collection that you just spent your rent money to buy. This also made the D-75A more versatile since it can double as a studio monitor amp when you have the need.
· AB+B class circuitry for a minimum of crossover "notch" distortion. This allows the amplifier to work at maximum efficiency while protecting against shorted, open, or mismatched low impedance loads.
· Input / Output Comparator to alert you of any distortion that is above 0.05% which provides you with a distortion free operation. This is extremely critical in studio situations.
· Detent level controls that allow you to easily recall settings you have used before.
· Convection Cooling System for quiet operation in critical applications such as studios, broadcast facilities, or any other environment that requires no external noise.
· XLR and ¼" Inputs
· Barrier Block Outputs

Sound Test

My first sound test was to run some studio monitors with the D-75A. The convection cooling made it a perfect candidate for this situation. The power is exceptionally clean and the unit adds no noticeable coloration to the signal that is being amplified. It allowed for much more power than would ever be needed in normal studio monitoring. At 55 watts per channel at 4 ohm, you can still blow your eardrums out in the confines of a control room or bedroom studio.

For the second part of my test I used the D-75A to power my single speaker cabinet. The results were amazing. Using the D-75A gave me outstanding results allowing me to get the most potential out of my speaker. Clean sounds were crystal clear and overdriven sounds were downright huge. Don't let the advertising fool you, 30 Watts can make a big noise! In larger venues, many players just throw a microphone or two in front of their cabinet and run those into a PA system. This gives the advantage of more power while maintaining the exceptionally clear tone of a single vintage speaker.

Out of curiosity, I even tried out my acoustic guitar and was amazed at the sound transparency. Generally it is very hard to get a good acoustic sound through an electric guitar amplifier. By using the preamp in my rack and the D-75A, I was able to get satisfactory results, although not quite studio level.

I do however have one small gripe about the D-75A. I would have preferred to have the option of ¼" outputs in addition to the barrier block. I am not a huge fan of the barrier block outputs except in permanent installation situations. But in Crown’s defense, I do not think they were designing this amp with the touring guitar player in mind but rather a more fixed solution for the above mentioned uses.

Closing Thoughts

Once you have spent some time working with amplifiers, you will realize that there is a reason the there are many different sizes on the market. Application demands just can’t support the one size fits all mentality. In fact, I am willing to bet that once you gain experience, you will be looking to downsize to a much smaller power amplifier.

In a field where most companies try to build a "bigger is better" amplifier, I find it refreshing that Crown decided to build a "smaller but better" amplifier. The D-75A is well designed and built. It is perfect for studio monitors, broadcast studios, paging systems, and for my favorite use so far, the guitar rack.

For other applications such as PA systems, Crown builds many larger amplifiers at different price levels. Be sure to check out their site for all their great products. Any amplifier you buy from Crown will assure you that you own one of the best on the market from a leader in power amplifier technology. The D-75A is now a permanent part of my guitar rig and they will be used to power my custom Tone-Tools guitar cabinets for many years. I award the Rig Ready Award for 2006.


Gary Allen

Copyright © 2006 Allen & Halberg Publishing, Inc.
All Rights Reserved
Guitar Gear Heads is a Division of Allen & Halberg Publishing, Inc.

Crown is a Harmon International Company