|   Digital amps-worth the wait? | Brotherman-5th floor
Apr 23, 2001 6:50 PM | | I'm contemplating whether to get a new amp or wait for digital amps to become mainstream. Since I plan to throw 3-4K in the amp I probably won't upgrade for 2-3 years. The current digital amps don't have digital inputs yet as far as I know (Spectron,Evo). Any ideas?
Sorry tube lovers, I like "sterile" digital sound so please don't tell me to get a mac. |
| oops-wrong forum nt | Brotherman-5th floor
Apr 23, 2001 6:50 PM | | . |
| re: Digital amps-worth the wait? | Michael C. Barnes
Apr 23, 2001 8:10 PM | | There is no such thing as a digital amplifier. Many people are refering to Class D or switching amplifiers as digital. They are not. These amplifier use a FET for the positive and a FET for the positive. They they take the analog input and switch it at a very high frequency. Doing this, they are able to achieve extreme efficiencies.
Bose built a Class D amplifier in the 1970s. A switching amplifier was described in a magazine article back in 1946.
Recently, several chips have come out that make it easier to implement Class D amplifiers. TI and others now have these chips.
The ideal application for these amplifiers are in batter operated devices--particularly laptop computers.
A company called Tripath has created a Class T amplifier. It is similar to a Class D but they use signal processing on the resulting signal to eleminate the switching distortion of Class D.
Generally speaking, the advantages to switching amplifiers is that they don't need expensive power supplies. Computers use very low-cost power supplies. You can get a 300 watts transformer for $15.00. A switching amplifier can use these power supplies and don't need expensive and heavy transformers that standard amplifiers need.
I have tested several of these switching amplifiers. I believe the Tripath parts sound pretty good. However, I do not believe you have the damping factory you can achieve with more traditional amplifiers. I also believe that there are too many disadvantages. The major disadvantage is the amount of noise the amplifier will generate.
The switching amplifers act more like transmitters than they do amplifiers. You need to carefully shield the amplifiers or it will generate a lot of noise.
In the end, I think that you are better off with traditional amplifiers unless your goal is to achieve very high efficiency or generate little heat.
I expect to see switching amplifiers becoming more popular because it will allow manufacturers to build units that are smaller, cheaper and lighter. |
| re: Digital amps-worth the wait? | Brotherman-5th floor
Apr 24, 2001 6:43 PM | | Interesting view Michael. And even though these amps should be called switching amps as opposed to digital, Spectron is talking about add-on cards with digital inputs. Don't you think that such an arrangement would be an advantageous as well? |
| re: Digital amps-worth the wait? | enzo
Apr 24, 2001 1:36 AM | | Definitely. The EVo particularly got rave reviews in Stereophile (class A status), StereoTimes, and Soundstage. The latter two are online. Well within your budget also. |
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