🚀 go-pugleaf

In <1992Dec31.014320.9693@midway.uchicago.edu> cal@gsbux1.uchicago.edu (Cal Lott) writes:

>Youngjoon Kwon     (415)926-2761 <YKWON@SLACVM.SLAC.STANFORD.EDU> writes:

>>If I don't use a phono input, is separate preamp necessary for
>>line level inputs such as CD, D/A, or tape? (Of course, except for the
>>control functions.)
>>
>>To be more specific, I am thinking of purchasing an Acurus amplifier
>>and I have two choices:
>>One is more conventional - get a pure power amp, such as A250 and a
>>separate line preamp, L10.
>>The other is to purchase a "direct-input-amp" DIA-100, which contains
>>passive control sections including source-switching and input attenuation.
>>
>>For now, I don't think I would ever need a 250w/ch capability of A250.
>>The only concern I have is whether a separate line-level preamp gives
>>any long-term benefit to the system.  (For a short term, I don't think
>>I can easily hear a sonic difference between the A250/L10 and DIA-100.)

Does this mean that the DIA-100 has a **passive** preamp stage?  If this is
the case, then your main concern should be whether to go passive or active.
Without getting crazy with theory or explanations, you should be aware that
passive preamplification requires careful cable choices and as large a
difference in impedance between the source output and the amp input.  I've
seen some outboard DAC's, for instance, which have < 10 ohms impedance.
These would work *very* well in a passive setup.  Others, however, with
500 ohms impedance, say, might need active preamp. to perform well.

Eric Hansen

--
* Eric J. Hansen                       |    Center for Clinical Computing   *
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