Too rich for his blood?
Editor: I love reading Stereophile, but the prices of most of the items reviewed are usually beyond my desired outlay. Have you ever had requests for something like "Best systems under $1000," "Best systems under $2000," "Best systems under $3000," or "Best mini-systems under $500"?
I realize Stereophile is not Consumer Reports, but I hope you might have a better ear. [This kind of coverage] would be appreciated…
The VK-5 and the VK-60 are fully balanced (differential) designs; balanced operation is maintained from input to output. However, both are…
I compared balanced and…
Finally, the VK-5 allowed music to be more dynamically alive. "Tico-Tico" (track 4, Beachcomber, Reference RR-62CD) played through the VK-5 sounded like a…
The comparison between the amplifiers confirmed that the VK-60 is quite special when it comes to harmonic accuracy. The Rowland Model 2 is no slouch in this area; in fact, its preservation…
All of the 8 ohm measurements on the VK-60 were made using its high-impedance output tap. Two and 4 ohm measurements were made at the low tap. Bridging was performed at the low impedance tap.
Following the 1/3-power, one-hour preconditioning test, the VK-60 ran typically hot for a tube amplifier. Its input impedance was too high to measure with precision on our Audio Precision test set using normal procedures, but was clearly well above 100k ohms. The output impedance measured a very high 3.5 ohms, or marginally less at 20Hz and 1kHz, increasing to 3…
Without any cathode follower, the VK-5's output impedance at its line outputs measured about 1.1k ohms. This is relatively high for a modern preamp, and reasonable care should be exercised in matching it with a suitable power amp. I recommend that the latter have a minimum input impedance of 20k ohms—not really a difficult condition to meet.
The input impedance of the VK-5 was very difficult to measure properly, due both to its being very high, and to small fluctuations in the readings, which are fairly typical of tube electronics. The lowest value I…