That is exactly what Berkeley Audio says. If I remember correctly, there was a vigorous discussion on Computer Audiophile where Michael Ritter from Berkeley Audio countered the claim by Miska from HQPlayer (total DSD enthusiast) that Delta-Sigma (D-S) by definition is DSD by pointing out that the Berkeley DACs, using Delta-Sigma modulation, are multibit (5 or 6 bits) and thus PCM.
If 1bit defines DSD then yes, any higher number of bits implies PCM. But I don't see it quite in such black and white terms myself, just my own view though.
The Computer Audiophile site is mucked up with the transition to a new design, so you can't find old posts, but fortunately I found Berkeley's statement in my saved old archives from that site.
Here is the post from 12-23-2013 by The Computer Audiophile, quoting Berkeley:
Hi Guys - I received one last
response from Berkeley Audio Design. It addressed some items directly.
Berkeley Audio Design:
DSD versus PCM part 2.
?
Initial assertion:
Multibit DSD is not PCM.
PCM is typically 24 bit of the whole sample value while multi bit DSD is typically 5-6 bits of DIFFERENCE between adjacent samples. In 1 bit DSD this difference is binary (0 or 1) while in multi bit DSD it's the same difference between samples but quantized with 5-6 bits (Sabre has a 6 bit DAC). Multibit DSD is BETTER than 1 bit DSD, so there is nothing wrong with going 1 bit> 6bit which is what all these DAC chips do.
Our assertion in response:
Multi-bit delta-sigma audio very definitely is PCM, and represents coarsely quantized whole output sample values being sent to a linear PCM DAC.
We have discussed the fact that multi-bit delta-sigma modulation is not the difference between adjacent samples at length in our previous post.
Going to a discussion of specific DAC structures does not even address our assertion.
It is true that typical monolithic multi-bit delta-sigma DAC’s use what is known as a thermometer DAC structure in which a series of current-source elements of equal value are switched on or off and their currents are summed to produce the output current. It is also true that, because the current output of each element can never be exactly same as the others, the resulting errors are normally scrambled and noise shaped by various schemes of mapping the required number of on current sources to different elements for each successive sample.
The number of elements, typically current sources, is normally an odd number, but this is not inconsistent with binary numbers. There is an extra state in which all of the elements are off, giving an even number of output states. For example, a 4-bit DAC would have 15 elements whose output sum goes from 0 to 15, which is 16 states.
It is not even necessary that the number of elements be related to a power of two. The nature of the delta-sigma algorithm and the element scrambling algorithm can map a binary number to a larger number of elements than the largest number represented by the binary number.
The important point to take away from the above is that the DAC itself is linear. It is true that the input to the DAC elements is unary coded, but what is not even mentioned in all the discussion is the mapping of a binary 5-6 bit input to a 32 or 64 bit unary code that actually controls the DAC elements. It would be absurd to think that much processing is done on 64 bit unary coded data. That is just the end result.
The multi-bit delta-sigma data stream is a series of 5-6 bit binary values or in some cases 8 bit data, i.e. PCM with noise shaping. These binary values are then translated into scrambled unary code just before the output elements. That unary code determines which elements are turned on, and the sum of theoutput elements, typically in current form, is the output of the DAC. In most designs, that current is converted to a voltage and then low-pass filtered with a conventional filter to yield the audio.
The multi-bit delta-sigma data stream is generated by a delta- sigma modulator, which is typically used to re-quantize and noise shape an input with a different bit depth. Each multi-bit word is a binary number which represents an instantaneous value of the signal – in other words PCM.
At Pacific Microsonics, prior to starting Berkeley Audio Design, we were directly involved in the design of several multi-bit DSM DACS, two of which were commercially produced by Japanese companies. These DAC’s all used the principles described above.