Class D Amplifiers?

I have been out of the game for a while. I guess it was about a decade ago that I stopped playing–that is the topic for another day, but in the meantime I find it amazing how much technology has changed! I recently picked up a new amplifier and speaker combo for playing my upright in Jazz combo situations. Just as a frame of reference I still have from my early-90’s-heavy-metal-days a Trace Elliot full stack (4×10 cab plus 1×15 cab) and a Gallien Krueger RB800 amplifier (slightly modified for more power!) all of which weighs roughly a ton (well at least a couple hundred pounds.) I can’t believe I used to take this stuff everywhere I was playing. Well, I am older now and have neither the patience or desire to carry heavy gear with me everywhere I go (ya, I know–you are thinking, but you play upright bass: probably the least portable instrument ever invented, and maybe there is some truth in that, but I digress.) Anyways–I wanted lightweight. Turns out that isn’t so hard anymore.

My new mantra: one trip from the car. I looked at the various choices available out there and there are a few nice ones these days. The top three were Euphonic Audio (EA,) Acoustic Image, and Phil Jones Bass (PJB.) I looked over the various offerings from each–my basic requirements were portability, direct out ability, sound clarity, portability, and finally portability (seeing a trend here?)

The PJB looked the coolest–they have a couple of small offerings–a briefcase sized amp and a suitcase sized amp, named aptly after their respective size factors. I looked around for a demo amp to try, but to no avail–the only local dealer was back ordered, and remained that way for months.

The Acoustic Image amps have a great reputation, and duly so–but the combo amps that fit the portability requirements I had all had downward facing cones. This has the added benefit of making the low end sound more pronounced for a small woofer, but my lessons in the past have taught me the first thing you do to make an amp sound cleaner is decouple it from the floor (the above mentioned tower of ear-splitting amperage almost always had a weight lifiting pad placed underneath to isolate it from the floor.) It’s just my opinion, but the design goes against what little bit I know about amplifiers.

So i finally ended up choosing the EA Wizzy 10 and their Class D amplifier, which finally brings me to the topic of this post. When I was playing 10 years ago a 300 watt amplifier weighed on average (not scientific here, just what my feeble memory can recall) about 10-15lbs. My new 300 watt amplifier is roughly three. Three pounds, wow! Wikipedia has a good article on the technical details: http://en.wikipedia.org/wiki/Class_D_amplifier but the basics are, that by using pulse modulation, and proper switching they can eliminate giant heat sinks and energy wasting transformers. Kickass.

So, how does it sound? I like it! It is clear, punchy, and it doesn’t have the muddy nature that larger amps do (and with an upright that makes a big difference,) the 10″ wizzy wouldn’t hold its own on any rock gigs–but that’s exactly why I wanted a direct out. Let the sound guy deal with it, I just _play_ the bass And the backpack case that EA sells for it allows me to practice my mantra (not just repeat it) I only make one trip from the car.