Class D Guitar Amplifiers May Be The Future

 

The First Commercially
Available Class D Amp 1964

Perhaps you were not paying attention, but Class D guitar and bass amplifiers are currently becoming very popular lately. Due to the lower costs many companies are pushing these class D modeling amplifiers over the original versions. Some players seem to like the to.

Fender Tone Master
Deluxe Reverb

Fender started with the Fender Mustang modelling amplifiers and currently are championing their Fender Tone Master series, which include the Tone Master Deluxe Reverb, The Tone Master Twin Reverb, The Tone Master Princeton Reverb, The Tone Master ’59 Bassman and others. 

Fender Tone Master
Twin Reverb

All of these amplifiers feature much more power than the originals and weigh so much less. The 100 watt  Twin Reverb that I used to tote around In the 1970’s weighed over 80 pounds. The Tone Master version comes In at a mere 33 pounds and  produces 200 watts of power into its twin 12-inch speakers.

The reason for most of the weight in the older versions was due to the necessary large transformers. 

Class D Amplifier

Due to the design of Class D amplification, the huge power transformers are no longer necessary, Class D amplifier utilize  a switching power supply (SMPS - Switch Mode Power Supply) instead of a large traditional power transformer. 

The SMPS is much more efficient than the traditional AC stepdown transformer to convert AC power to Direct Current and can be made much smaller and lighter.

Rumble 200 - Class D
Bass Amplifier

Where traditional Class A or Class AB tube amplifiers were the standard for years, the Class D amplifiers operate more efficiently. With the advantage of modeling software and hardware the guitar and bass sounds available are very close to the original tube versions. 

Crate Power Block

There are a lot of companies that have offered class D amps that you may not have known about. In the early 2000's Crate offered the tiny Power Block amplifier head that produced 150 watts of class D power.

 It was small enough to fit in a guitar case. 

Acoustic Image Clarus

Acoustic Image amplifiers were popular with Jazz players due to their compact size and incredible power derived from the class D design. 

Ampeg V12 Bass Head

Some Line 6 amps utilize class D.  And there are so many bass amplifiers that utilize class D. TC Electronics, Gallien Krueger, some Ampeg, and even some Mesa Boogie all have class D power. 

Though this all seems to be a perfect solution, class D amplifiers may have some drawbacks. including potential for distortion, complexity in design, and sensitivity to power supply noise. And though they are  generally more efficient, class D amps still require protection against overheating, especially when delivering high power for extended periods,  

Tone Master Super Reverb
'65 Tube Super Reverb

There is criticism about Fender's Tone Master amplifiers by those comparing them to the original tube models these amps are based on. In my opinion the difference is minimal. The Fender Mustang series has been around for years and most users are quite satisfied with that product.

 

Some of the early Class D amplifier designs had a reputation for failure, however modern, high-performance designs are becoming more reliable.

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