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Use of Digital Amps: Need serious help

Hi i recently got out of the audio deal and sold my entire system. It was too much for me. While randomly scouring the net i came across an interesting product the Spectron Musician II. This amp essentially has a dac built into it. Apparently all digital amps take the analog signal that you send it and use an A/D converter to digitize it, then amplify it digitally and send the signal to the speakers. The Spectron (along with the new Tact 2150) allows you to never covert the signal to analog ever, and i mean never, the signal is digital (which makes no sense actually) when it reaches the speakers. So in effect all you need is a transport because the Spectron and the Tact both have built in volume controls. So now this allows me to have a potentially extremely very good system, (I know the tact and spectron are both incredible amps when fed analog signals) for next to nothing. In my old system my cd player, an audio aero mk II which was jaw droppingly good i might add, alone would cost me far more than my entire new system. So now the question is... after all of this... does anyone have any experience with running a purely digital signal versus digitizing an analog one with any of these amps? How good is this technique and how important is it to have a good transport, cost is no object really. I won't reenter the audio world if my new system will not be comparable to my old one. So if anyone knows let me know if this is a good technique. Thanks in advance for your help.
lordgorian
morasp
48 posts
 
I didn't realize that Spectron had released the digital input option. They have been talking about it for quite a while. They do have remote sense speaker cables that a lot of people like. Spectron was working on speakers that had a digital amp for each driver. Kind of like the waveform speakers that have since gone out of business. But at one of the trade shows they couldn't get a prototype working. The other digital amplifier is the Tripath module which is used by Bel Canto and some new products coming out in Europe. It calls it's technology Class T becuase the output frequency is variable spread spectrum up in to the megahertz range. Spread spectrum supposedly eleminates digital noise at a sigle frequency by speading over a frequency range giving a cleaner output.
kana813
956 posts
 
Spectron has not released the digital input option, yet.

Some other interesting digital amps are the Carver Pro ZR
series.
peak
26 posts
 
It is possible that a new paradigm is created whereby digital input feeds such as PCM (analog level represented by magnitude of digital code at 44KHz/nyquist) can be directly converted to PWM (average loudness represesented by a dgitally derived "on" interval...the duration of this interval has the analog loudness information)via computation. Similar to a single bit DAC (or DSD) with the filtering done right at the output via a inductor. This would be very DIRECT and maybe this is what people mean by direct digital.

However, if the analog input is cleaner, then it means that the digital siganl is converted by onboard DAC to analog. This intermediate signal would then need to derive the "fixed interval duration" via an analog to digital process (ADC) to set drive the class D output stage. For the case of analog inputs, the "extra" DA conversion needed by digital inputs would not be needed.

If you ask the above theorectical question to the designer, it should indirectly answer the question about how things are done.
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