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From: mm@mvuxd.att.com (Martin H Meyers)
Newsgroups: rec.audio.high-end
Subject: bi-amping
Message-ID: <8661@uwm.edu>
Date: 3 Jan 91 13:56:24 GMT
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Approved: tjk@csd4.csd.uwm.edu
Originator: tjk@csd4.csd.uwm.edu


      I am interested in bi-amping by B&W 801s (currently bi-wired with
Tara Return).  I have a lot of questions:

1.  How much power is required for the tops (mid-range and tweeter) where
the cross-over is, I believe, around 300 Hz?  I'd like to use a low to medium
power tube amp (less than 100 watts per side).  How much is necessary?

2.  Is an active cross-over required or can I simply feed the passive crossover
already used for bi-wiring?  I have a dealer who says I need an active
crossover if the top and bottom amps are not identical.  Could someone give me
a technical explanation in more detail.

3.  I am currently playing around with modifying an ST-70 (Curcio mods ala
Glass Audio).  What I do not have is any original documentation or schematics
for the ST-70.  Could someone please send me a copy?  I'll glady reimburse
for any copying charges, etc.  Anyone with experience with the Curcio mod or
other updated ST-70s?  

4.  The ST-70 has a mono switch which I assume (no schematic) doubles the input
feed and parallels the outputs to double the output power to 70 Watts mono
power.  How does this sound?  Any compromises involved in bridging to mono?
Can bridging to mono be done with the Curcio mod as well?

5.  The Dynaco is currently driving my bedroom speakers.  Would anyone hazard
an opinion on using them on the top of the 801s????


Thanks in advance,

Marty Meyers