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In Reply to: Sound lab bias........ posted by tyu on January 8, 2014 at 02:48:34:
On the Quicksilver preamp: To a large degree its sound can be tuned by the choice of capacitors. There is some unit to unit variation in the RIAA network, so far as I can tell, because the schematic that Mike Sanders sent me shows slightly different capacitor values from what is actually in my unit. My unit has four .022uF capacitors (two per channel) for RIAA. I replaced them all with Russian SSG types. OMG, what a fantastic improvement. Those are wonderful capacitors. Then also the coupling caps between phono and linestage and between linestage and output make a big difference. However, there are two things in the circuit design that may make it lean toward an SS sound. One is the NFB in the linestage. Another are the zeners used in the PS. I toyed with the idea of revising the linestage to get rid of the NFB, but I did not want to destroy the pristine originality of my unit. Plus, it does sound excellent, and it certainly is not "lean" or harsh sounding. Just a little more toward SS vs "tube". Another upgrade that I did perform on mine was to ditch the 12AU7 at the input to the linestage, in favor of another 12FQ7. (Which is to say that my linestage now uses two 12FQ7s and one 12AX7.) The latter is a much better sounding tube, and I can hear a big improvement. (12AU7 is not my cup of tea at all, no matter how fancy the brand or the vintage.)
I have not heard my SLs in a while, but my impression is that the Bevs do have a subjectively more extended top end. A lot of this may have to do with the way you listen to the Bev. Speakers are sideways facing each other, and I sit only about 7 feet away from a straight line that could be drawn between the lenses of the two speakers. There is a brick wall about 6 feet behind, at the rear of my room, from that same straight line. The SLs are in a much bigger room, are operating in true bipolar, and are farther away from my listening position. HF response will appear to deviate much more, depending upon where you sit or stand.
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Follow Ups
- RE: Sound lab bias........ - Lew 07:12:45 01/08/14 (0)
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