Mapman, thank you kindly for the nice words.
I haven't ever experimented with any kind of passive preamp, or with direct drive from a source component, because in my case it would pretty much be a non-starter functionally. I have five sources, having widely differing output impedances and levels; and my preamp supplies outputs to three destinations (I could readily do without one of them, the record out to my tape deck, but I definitely need outputs to my headphone amp (which I drive from a second tape out) and of course to my power amp). Also, the cable length from preamp to power amp is long enough to be something of a concern with many passives.
Regarding your question about why some people who've tried both approaches report better results with actives, even if cable lengths, cable capacitances, and impedances are all ostensibly suitable for a passive, I would speculate that one reason is that discerning listeners having resolving systems can hear effects attributable to those parameters to a degree that is somewhat greater than would be expected on the basis of conventional analysis.
A speculative and hypothetical example, to illustrate my point: If the combination of cable capacitance and the output impedance of a passive preamp (which will depend on the setting of its volume control as well as on the output impedance of the source component which drives it) results in a bandwidth of say 50 or 100 kHz, that would ostensibly seem likely to be sufficient. But perhaps in combination with bandwidth limitations elsewhere in the system the result might be phase shifts in the audible upper treble region that are sufficient to produce time domain misalignment of those frequencies relative to lower frequencies, to a degree that may be perceptible under some circumstances. In other words, more bandwidth margin may be necessary in some circumstances than is commonly recognized.
I'd imagine also that a contributing factor in some cases is along the lines of the point George has made in a number of threads, that active circuitry may be introducing colorations that are euphonic. Not that there's **necessarily** anything wrong with that, IMO.
Another reason may derive from the combination of the facts that it seems clear that not all cable effects are technically explainable or predictable, and passive preamps (or at least resistance-based passive preamps) can be expected to magnify cable effects as a consequence of their relatively high impedance levels.
The point that was made earlier about sonic degradations being introduced by the parts in a passive preamp probably also has some validity in many cases, but FWIW my own instinct is that if those parts are chosen to a high standard interface effects are likely to be more significant. Others may disagree.
And in situations where digital volume controls in source components are being used in lieu of having any preamp, presumably "bit-stripping" would be a factor in some cases.
So I think that the answer to your question of "why" is multi-faceted. And I certainly wouldn't rule out that in at least a few cases the "why" might simply be user error in configuring the application.
A lot of experienced based opinions have already been expressed in this thread, from many whose opinions I have great respect for. As you said initially, there is no single right and wrong answer, that will be optimal in all circumstances. But FWIW mine own instinct (based, as I said, on having no experience with passives) is that Brownsfan's particularly nuanced post rings especially true.
Best,
-- Al
I haven't ever experimented with any kind of passive preamp, or with direct drive from a source component, because in my case it would pretty much be a non-starter functionally. I have five sources, having widely differing output impedances and levels; and my preamp supplies outputs to three destinations (I could readily do without one of them, the record out to my tape deck, but I definitely need outputs to my headphone amp (which I drive from a second tape out) and of course to my power amp). Also, the cable length from preamp to power amp is long enough to be something of a concern with many passives.
Regarding your question about why some people who've tried both approaches report better results with actives, even if cable lengths, cable capacitances, and impedances are all ostensibly suitable for a passive, I would speculate that one reason is that discerning listeners having resolving systems can hear effects attributable to those parameters to a degree that is somewhat greater than would be expected on the basis of conventional analysis.
A speculative and hypothetical example, to illustrate my point: If the combination of cable capacitance and the output impedance of a passive preamp (which will depend on the setting of its volume control as well as on the output impedance of the source component which drives it) results in a bandwidth of say 50 or 100 kHz, that would ostensibly seem likely to be sufficient. But perhaps in combination with bandwidth limitations elsewhere in the system the result might be phase shifts in the audible upper treble region that are sufficient to produce time domain misalignment of those frequencies relative to lower frequencies, to a degree that may be perceptible under some circumstances. In other words, more bandwidth margin may be necessary in some circumstances than is commonly recognized.
I'd imagine also that a contributing factor in some cases is along the lines of the point George has made in a number of threads, that active circuitry may be introducing colorations that are euphonic. Not that there's **necessarily** anything wrong with that, IMO.
Another reason may derive from the combination of the facts that it seems clear that not all cable effects are technically explainable or predictable, and passive preamps (or at least resistance-based passive preamps) can be expected to magnify cable effects as a consequence of their relatively high impedance levels.
The point that was made earlier about sonic degradations being introduced by the parts in a passive preamp probably also has some validity in many cases, but FWIW my own instinct is that if those parts are chosen to a high standard interface effects are likely to be more significant. Others may disagree.
And in situations where digital volume controls in source components are being used in lieu of having any preamp, presumably "bit-stripping" would be a factor in some cases.
So I think that the answer to your question of "why" is multi-faceted. And I certainly wouldn't rule out that in at least a few cases the "why" might simply be user error in configuring the application.
A lot of experienced based opinions have already been expressed in this thread, from many whose opinions I have great respect for. As you said initially, there is no single right and wrong answer, that will be optimal in all circumstances. But FWIW mine own instinct (based, as I said, on having no experience with passives) is that Brownsfan's particularly nuanced post rings especially true.
Best,
-- Al