The magnitude of RIAA error is not particularly useful unless we also consider the range of frequencies that are affected by the error. in practice, a 1dB deviation that only hits one note is not going to be very noticeable, but a 0.1dB error that spans an octave or more can be quite noticeable. In fact, the manner of musical presentation changes when this happens. That said, I do think that the less total deviation there is from the RIAA curve, the better. True, LP recordings and mastering systems have their own deviations, but they can deviate in any direction, and as long as we keep as close to the standard curve as we can, the frequency deviations in one's LP collection should average out. At least we won't be favoring certain recordings over others, which would certainly be the case with an RIAA playback network that wasn't right.
I don't think that speaker colorations are an acceptable excuse to tolerate RIAA deviations. Admittedly it is next to impossible to exactly duplicate electronic colorations in the speaker and vice versa so that they can be truly compared, but at least in my experience, it has seemed that electronic colorations are much more noticeable and less forgivable than speaker colorations. I think that this is because acoustic colorations in the environment are part of everyday life, and compensating for this is a constant, subconscious process.
Regarding when balanced phono amps were introduced, I have on my bench a schematic for a discrete FET balanced phono amp from the Japanese audio magazine M&J which is dated January 1985, and I am pretty sure that there are earlier examples (especially from the tube guys).
I don't think that complexity in a design is necessarily a bad thing, because a major goal of this approach should be to get smaller "modules" with more well-defined tasks/behaviour/environment. This makes it easier to design, understand and debug the functions and can lead to better performance, even if the overall complexity becomes greater. A simple circuit can lead to a wider, less clearly defined range of responsibilities being assigned to fewer parts, and this can result in lower performance.
IME, NFB is just another tool, neither good nor bad by itself. The results of using NFB have a lot more to do with the capabilities and sensibiities of the designer than NFB per se. I usually dial in the amount of NFB by ear as well as by measurement, and sometimes I'm at 0dB of NFB, sometimes 50dB.
Although I fully agree with the "holistic" approach, I think it is possible to achieve a good-sounding line or phono amp using a variety of technologies, circuits and approaches. However, topologies and components by themselves don't know what they are supposed to sound like. Good sound, bad sound, they don't know any better. The most important component of all is the designer, and the final sound extracted from the topologies and components is only as good as the designer allows.
regards, jonathan carr
I don't think that speaker colorations are an acceptable excuse to tolerate RIAA deviations. Admittedly it is next to impossible to exactly duplicate electronic colorations in the speaker and vice versa so that they can be truly compared, but at least in my experience, it has seemed that electronic colorations are much more noticeable and less forgivable than speaker colorations. I think that this is because acoustic colorations in the environment are part of everyday life, and compensating for this is a constant, subconscious process.
Regarding when balanced phono amps were introduced, I have on my bench a schematic for a discrete FET balanced phono amp from the Japanese audio magazine M&J which is dated January 1985, and I am pretty sure that there are earlier examples (especially from the tube guys).
I don't think that complexity in a design is necessarily a bad thing, because a major goal of this approach should be to get smaller "modules" with more well-defined tasks/behaviour/environment. This makes it easier to design, understand and debug the functions and can lead to better performance, even if the overall complexity becomes greater. A simple circuit can lead to a wider, less clearly defined range of responsibilities being assigned to fewer parts, and this can result in lower performance.
IME, NFB is just another tool, neither good nor bad by itself. The results of using NFB have a lot more to do with the capabilities and sensibiities of the designer than NFB per se. I usually dial in the amount of NFB by ear as well as by measurement, and sometimes I'm at 0dB of NFB, sometimes 50dB.
Although I fully agree with the "holistic" approach, I think it is possible to achieve a good-sounding line or phono amp using a variety of technologies, circuits and approaches. However, topologies and components by themselves don't know what they are supposed to sound like. Good sound, bad sound, they don't know any better. The most important component of all is the designer, and the final sound extracted from the topologies and components is only as good as the designer allows.
regards, jonathan carr