GAS Thaedra - Operational Theory

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丁HAEDRAhasbeenalongtimecominganditsconceptsarearadical
departurefromanythingthathasexistedbeforeMechanica‖
yand
electrica‖
y,THAEDRAisunique:
Frominputtooutput′ 丁HAEDRAis100percentfu‖
―
complementary′
aconceptorigina‖
yconceivedbyG.AS.Cornpanvengineers.As
versat‖
eastheunitis,thereareonlyょ И
ノ
OStagesofamp‖
fication.AII
otherpreampsusethreeormorestageswhichaddtocolorationand
irnpairtheirabilitytoachieveatota‖
yopen′
unrestrictedsound
quality.
A‖ direct(D.C.)cOupledampl汗
ierssufferfromaproblemknownas
d.c.drift.Accompanyingthisdriftislowfrequencymodulationnoise.
UntilnoM4theonlywaytoeliminatedriftwastousecapacitorcoup‖
ng
orgiganticamountsofnegativefeedback;hardlyelegantsolutions.
EntertheSERVO.
丁heconceptofservo‐ controlhasfoundmanyapplicationsbuthasnever
appearedinaudioelectronヽ cs.lnttHAEDRA′ servoamplifiers(com‐
pletelyoutsidetheaudiostream)contrOlabsolutelya‖
d,c.voltages.
Theresultisthataftertheinputcouplingcapacitorsinthephono
circuit′
THAEDRAis
′θθ
ρ
θrεθ77D.C
ε
ο
%ο
た
σ
―
―
―
theonly
preamplifierinexistencevvhichis.
THAEDRAisunique:lthasatrulylow―
noiseHeadAmpforusewith
lou〆
‐
output′
moving‐
co‖ cartridgesltisafactthatthemoving― coil
cartridgetracesinthesamemannerastheheadinadisccutterTheir
abilitytoalrnostexactlyreproducethesignalengravedonavinylgroOve
isunpara‖ eledUnfortunately′
uptonolA/theirverylovげ
outputs
requiredtheuseofeitherastep― uptransformerorapre‐
preampto
achievethenecessarygainThetransformershaveseverefrequency‐
responselimitationswh‖ etheava‖ ablepre―
preampSsufferfromnoise
anddistortion.Ontopofthis,bothrequiretheadditionaluseofa
phonopreampcircu仕
′
σ
ddinglinksintheaudioch9inwhiChfurther
degradesoundqual:ty.丁
HAEDRA'Ssing!elow‐
noiseHeadAmpcircuit
feedstheline‐amplifierdirectly′
usingiusttWOStagesfrominputto
output.丁 heHeadAmpis,ofcourse,servo‐ contro‖ ed
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THAEDRABLOCKDIAGRAM(CHANNELAONLY.)