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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
peter_s
1,335 posts
 
LG,

I just want to share my understanding of how digital amps work - derived from the PS Audio page for the HCA-2 (a Class D digital "switching amp"). In your entry, you note that:

"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."

That is generally true, but I think it's important to recognize that the HCA-2 doesnt' digitize the analog signal into a digital pattern such as that found on a CD. Instead of trying to simulate the wave form that represents the music, what it is doing is giving the amp instructions to pass 100% of its power generation through or to cut it off, and the timing of those "ons" and "offs" is modified by circuitry to then create the wave form. So, the pattern of "offs" and "ons" the amp generates is different than the digital waveform shown on a CD. Perhaps the Spectron and the TacT work differently, but this is my understanding of how the HCA-2 works. If this is correct, "all" digital amps are not the same.

Clarification welcome! I hope this is useful. Peter
_scotty_
12 posts
 
You might want to talk with John Ulrick at Spectron.He is very friendly and informative.He could explain how the direct digital input works and how digital volume control is achieved.Contact information can be found here http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1064000511&read&3&4&
lordgorian OP
133 posts
 
The volume control in both of these amps are digital. But none the less there appears to be no loss of data because the volume is regulated differently, while the data is PWM and not PCM anyways, digital amps in my experience sound like a mix between tubes and SS they are liquid but extremely clean, a great combo but could use better depth. None the less, im looking for experience and not oppinions about what this might sound like. Im hoping someone with experience with the Tact components can help me. Thanks.
unsound
7,329 posts
 
If you go to the TacT web site, you'll find a link for a TacT users site.
eldartford
4,262 posts
 
The greatest advantage of digital technology (in general, not just for audio amps) is much lower cost for the same performance. And regarding performance (sonic quality in our case) it can be anything you want it to be with the right software, or other means of digital data processing (eg: firmware).
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