Most signal processing circuits and circuit controls work with operational amplifiers, also known as op-amps. These are integrated analog circuits capable of picking up the subtlest frequencies for perfect sound production and overall media production. Older recordings which have been converted to digital constants can still be used to retrieve analog data with the proper tools on hand for a sound engineer to work with. Though these are still integrated circuits, they are widely used and found in most systems.
Op amps and the Microchip functions they perform are commonly overlooked or missed in some way. Designers and engineers do not always consider the intricacies of operations within this microscopic integrated circuit chips. The relative inundation of modern developments tends to obscure previous, existing technology which has been a driving force all along. It is a challenge to learn everything in the field of technology and be aware of the past without proper training.
Resources are available on the internet to better understand the technology we already must work with and improve upon, if it even requires improvement from any stage. Op-amps are common and simple, but they are need for proper digital conversion of signals, picking up analog where digital would fail. Eventually this can be integrated into a digital signal and changed, tweak, or amplified as needed through digital control while retaining the analog sound on a consistent digital level.
Digital signals do not change at all. They always contain the same data unless the data is changed. Analog signals, on the other hand, do change over time as they are transmitted from source to source. We have so many digitally “remastered” recordings because of this. What the remaster does is restore the analog signals lost in translation over time. Then you can take on the later technological needs and mathematics needed to bring sound to perfection.