Direct Digital amplification (Active)

[John]

Has anyone got any experience with direct digital amplifiers I am interested in hearing from anyone who has integrated this in active system using DSP to control x over but also anyone just running a direct digital amplifier. I been reading up and it is supposed to take digital to the next level as less conversion going on in the system

[Markiii]

you can't really amplify in the digital domain, so the same amount of conversion is being done

in one sense your doing more as the crossover processing is done actively rather than passively


it can be better, it can be worse, all down to how well its done

[nat8808]

I've only just heard of it, but a little bit of reading up just now:

I'm not sure about less conversion but conversion at the last point and a different kind of conversion to the usual PCM to voltage/current level.

It involves a PCM to Pulse-Width Modulation conversion which can then be used to drive the Class-D amp directly rather than PCM -> analogue -> PWM -> Class D amp. PCM to PWM is D/A conversion but to a signal our normal pre-amps and amps won't work with.

So Direct Digital is marketing mis-direction but no more so perhaps than calling Class-D amps "Digital amplifiers". PWM is definately an analogue form and signal..

Ok.. so that looks like less conversion but I meant it doesn't mean less of the usual D/A conversion as we normally speak of it - just negates the traditional voltage variation analogue bit in the middle when using a Class-D amp. There is always an analogue to PWM converter in a Class-D amp because a Class-D amp is a PWM amplifier..

If I remember correctly from a magazine I have form the late 80s, before Sony's PCM digital standard became the norm, dbx had a kind of PWM digital system. Now that would have meant less conversion but alas the world took the PCM path..