🚀 go-pugleaf

A day or two ago, I heard another one bit D-to-A algorithm from a
strictly unreliable source.  (A musician friend of mine.)  Since
1 bit D-to-A was a recent topic, I thought I'd share this one with 
with the net.  He claims this new revolutionary algorithm uses one
bit to tell whether the output voltage should be incremented or
decremented from its current state.  i.e. Voltages are not quantisized
by binary words.  If the bit is a zero the exsisting voltage will be 
say, decremented by a given value.  If the bit is a one, the voltage 
will be incremented by the same value.  (I don't know if actually 
0=decrement and 1=increment, but you get the idea.)

Now I'm only an undergrad in EE and I haven't studied dsp much, but
I cannot see how to actually implement this.  I see a few problems.

1.  What do you do if the voltage stays the same? Would you just
go ahead and decrement or increment and hope that it doesn't screw 
you up in the longrun?  

2.  How fast would you take these one bit samples?  I don't suppose
the Nyquist sampling theorem would still hold since you are no longer
just dealing with a voltage level.  Take, for example a high frequency 
signal with a large amplitude.  This causes a large jump in your output 
voltage (jump >> increment value).  You will need a number of samples 
to reflect such a jump.  Conversely, if you are sampling at a very high 
rate, you will run into problem #1 with low frequency signals...You will 
have points at which the voltage doesn't change.

I can see an advantage however.  This algorithm, coupled with a very
small increment/decrement voltage, can allow for very high resolution
which is not available with a standard 16 or even 32 bit D-to-A conversion.
(But then again, you need a high sampling rate for high frequency signals,
which can lead to problems with the amount of available memory..)

Would anybody else like to comment?

pjz...

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