Originally Posted By: nixmikspop
Originally Posted By: Ritz2
Originally Posted By: nixmikspop
I would love to see a digital amplifier. And would love even more to have a new Outlaw 978 pre/pro to hook it up to.


I've been asking about an efficient class D/H/whatever "digital amp" around here for years. There doesn't appear to be much interest. I kinda like the Wyred4Sound multi-channel offerings. They're competitively priced compared to Outlaw's amps and are 80-90% efficient.


I am very surprised that more companies have not been coming out with some type of digital amplification over the last few years.


There are in fact many on the market, so much so that some companies with their own original designs have gone under.

Digital amplifiers are a misnomer for what should be really be called "class D" or switching power amplifiers. The "D" doesn't even stand for digital but it was simply is the next letter in the alphabet to come after c; class C was the previous classification in amplifier topology design. They use a technique called pulse wave modulation (PWM) and the designs are similar to modern computer power supplies.

Since the first short-lived commercial class D amplifier to come to market in 1974, designed by John Ulrich (now owner of Spectron) and an unsuccessful attempt by Sony circa 1978, there had been a 20 year hiatus for class D amplifiers on the market. In 1998, Tact Audio brought to market the Tact Millennium which is an audiophile integrated amp ($10K) and soon after Spectron came with a new design eventually followed by others.

There are now in the market over two dozen different class D design topologies like Spectron, Equibit, ICEpower, UcD, Tripath, Zetex, D2Audio, NuForce to name just a few. Some design houses produce the basic class D amplifier modules based on their usually patented topology and sell them or license the design to the amplifier manufactures (or integrators) that build the final amplifier by adding the power supplies, the cases and often making a few tweaks to the basic modules. Some integrators of these ready made class D modules include some well known brands like Audio Research, Jeff Rowland, Bel Canto, Rotel, NAD, etc.

Furthermore, some big names in the industry have developed their own class D topologies that they use exclusively in their own products like Sony, Halcro and late last year even Marc Levinson. And then there's a plethora of small really obscure brands that even many audiophiles haven't heard of, some of which have come and gone as happens often in this industry.

So there are now literally dozens of manufacturers that make class D amps of all sorts. You just have to dig a little deeper and you'll be surprised by how many there are with prices starting at under $100 and well upwards of $25K.