The way to natural sound
Metrum Acoustics is a division of All Engineering
All Engineering is a company with a history of innovation in many fields within the world of electronic design. Within the field of hifi All Engineering is primarily known for its brand Metrum Acoustics. Particularly within the field of electrostatic speaker systems All Engineering has experience dating back to 1989. In a later stadium of development broader applications for electronics were added to that. For the industry a diverse selection of products has been created, with its principles always founded in the fields of electronic and acoustic systems with digital signal processing playing a significant part.
When one turns the attention to digital systems within the field of hifi, the diversity of its components is extremely limited. The manufacturers that supply these components decide how signals should be processed by not supplying alternatives and therefore also greatly influencing the sound image that is created. The current trend among manufacturers is to include techniques such as ‘oversampling’ and ‘upsampling’ within the chip itself, forcing designers to utilize these techniques for their products. Incidentally, it also means that many brands systems use the same building blocks and that the sound image of these systems betrays what components have been used.
If a designer feels that things should be done differently, then he is forced to choose between the limited variety of building blocks, or to find refuge within the selection of far older components.
Techniques such as ‘oversampling’ and ‘upsampling’ were created to fulfill the need to smoothen the conversion process from ‘digital to analogue’ and to prevent phase distortion. Particularly during the years directly after the introduction of the CD-player, the conversion methods that were used proved not to be free of sonic artifacts and thus insufficient. In response to that strong filtering was introduced and the oversampling technique was born. Though fans of the technique can’t stop singing its praises, fact is that oversampling and upsampling have disadvantages which manifest as transient response in earlier mentioned systems.
Nowadays there is a large group that prefers ‘non-oversampling’ (or shortly, NOS), but that has to make due with old chips, with all the consequences thereof. All Engineering has dedicated a lot of its time and attention to researching the premise and endorses the validity of the audible benefits, up to a point. The question then turned to removing the sonic artifacts, without resorting to oversampling. A question that has been answered by the NOS mini DAC: a digital to analogue converter that has been constructed with modern, industrial chips and which is free of many of the disadvantages of the past. On this dedicated website you can read how the NOS mini DAC turned from a wild idea into a success, and how the successors of the NOS mini DAC further improved upon the concept.