restorer-john
Grand Contributor
It shouldn't cost too much to get good phono performance, but the design considerations are significant and the engineering effort that went into phono stages to achieve excellent perfromance in the vinyl days was costly.
Components such as multiple paralleled JFET discrete differential input stages, ultra low noise and high gain discrete devices, often with completely separate and optimized stages for the characteristics of MM and MC cartridges made for relatively expensive preamplifiers.
DAC 'design' these days seems to be either a tweaked application-note design in a pretty can full of 'audiophile approved' components (ie, the ones with the pretty coloured sleeves, gold labels and esoteric names) or a serious design effort, backed with solid engineering and containing components fit for purpose, along with measured results to back that up (Benchmark etc).
Headphone amplifiers are a bit of a joke to me. Basically, most of them are a low power, class AB amplifier in-a-can at ridiculous money. As long as you can swing a decent voltage at essentially zero output impedance, can produce a nice clean square wave and the residual (noise uV) is extremely low, you have a headphone amplifier.
Headphones are not a difficult load. Some people like to believe their headphones are special because someone told them they are 'so difficult to drive'. That's BS. It makes them feel superior and justifies their need to buy some overpriced amplifier. I know plenty of audiophiles who love to boast their speakers are 'such a difficult load' that most amplifiers can't handle them. I tell them they are poorly designed, not difficult. In most cases, when you plot an impedance sweep, they are not that bad at all and most competent amplifiers can handle them easily. Much of it is internet folklore.
I would say older preamplifiers not using an opamp in the headphone stage (using tr buffers) can be perfect headphone amplifiers, with performance that walks all over the things I see peddled these days.
A headphone/DAC however is a different story, and IMO, a very useful device for on-the-go listening or upgrading.
Components such as multiple paralleled JFET discrete differential input stages, ultra low noise and high gain discrete devices, often with completely separate and optimized stages for the characteristics of MM and MC cartridges made for relatively expensive preamplifiers.
DAC 'design' these days seems to be either a tweaked application-note design in a pretty can full of 'audiophile approved' components (ie, the ones with the pretty coloured sleeves, gold labels and esoteric names) or a serious design effort, backed with solid engineering and containing components fit for purpose, along with measured results to back that up (Benchmark etc).
Headphone amplifiers are a bit of a joke to me. Basically, most of them are a low power, class AB amplifier in-a-can at ridiculous money. As long as you can swing a decent voltage at essentially zero output impedance, can produce a nice clean square wave and the residual (noise uV) is extremely low, you have a headphone amplifier.
Headphones are not a difficult load. Some people like to believe their headphones are special because someone told them they are 'so difficult to drive'. That's BS. It makes them feel superior and justifies their need to buy some overpriced amplifier. I know plenty of audiophiles who love to boast their speakers are 'such a difficult load' that most amplifiers can't handle them. I tell them they are poorly designed, not difficult. In most cases, when you plot an impedance sweep, they are not that bad at all and most competent amplifiers can handle them easily. Much of it is internet folklore.
I would say older preamplifiers not using an opamp in the headphone stage (using tr buffers) can be perfect headphone amplifiers, with performance that walks all over the things I see peddled these days.
A headphone/DAC however is a different story, and IMO, a very useful device for on-the-go listening or upgrading.
