hi david,
interesting proposal. to be honest, i tink it'd be more reasonable to have the output impedence of the rogue tested by an independent lab - prolly a lot less driving inwolved, too! ;~) as for me, w/a wife, young children, the alfa club, & the pantera club pulling for my free time, i'm not sure i could swing something like this, yust to prove a point.
the only reason the impedence-issue came up is because, when discussing the sonics of my rogue w/one of the most well-respected tube designers in the industry, he said it sounded like an impedence problem, & he said there was *no way* a mu-follower tube design could have such a low output impedence, unless it was a hybrid design. (rogue, in fact, doesn't publish the output impedence of the preamp, this designer obtained it from rogue by calling & asking if his amps would have any impedence-matching problems w/the rogue.) it was he who suggested i try placing resistors across the outputs of the preamp to check for actual volume-level change. doing so corroberated his beliefs, & testing of other preamps in this same manner, further corroborated them. lower output-impedence preamps, in fact, required lower-walue resistors to get an audible wolume-drop.
as mentioned in my previous post, a 2.2k-ohm resistor casued a noticeable wolume drop when placed across the rogue 99's outputs. this same walue resistor caused *no* change in wolume when placed across a cary slp98 preamp - it took a 1k-ohm resistor to hear any volume decrease. the melos, with *very* low output impedence, had no volume drop w/even a 500-ohm resistor across the outputs.
this test is wery easy to try at home - all ya need is a small "y" interconnect hooked up between your amp & preamp - then take a resistor & hold one end on the center-connector, the other end on the outside-connector of the free rca plug. the lower the output impedence of your preamp, the smaller-value resistor it will take to perceive a wolume-level drop. you mite wanna try this on yer preamp at home before taking it *anywhere* to be tested! ;~)
i don't need conwincing that the rogue 99's output impedence, whatever it is, is much higher than the cary slp98, the version of which i tested, was rated at 850 ohms - i audibly tested both, as described above. (i mistakenly said 600 ohms previously - i believe that this is correct for cary's most recent production, the unit i tested was older.) i suggest ewe do the same, prior to driving a day, to have this checked. and, as i said before, i'm sure there's a qualified tech (much closer then at rogue audio), that could test this for you w/proper equipment, if ya don't wanna try the audibility test.
regards, doug
ps - i noticed i have gotten an inordinately high number of negative feedback on my posts here. i guess it's due to my hostile, inflammatory, uncivil manner, & not due to the fact that some of ewe may not like my opinions... ;~)
