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Kenwood
KA-7002
(c. 1971 ?)
Big
DC-coupled integrated amplifier of... 10kg - the twenty or thirty
kilo monsters were for later years.
If
I deciphered properly the poetic translation of this rare and undated
catalog :
The differential amp stage is made
around hi-temperature transistors in the first and second stages,
with a Zener diode stabilizing the 1st stage, by way of 100% counter-DC
current... to stabilize static mechanical charge in the loudspeakers'
voice coils. As this differential amplification is also present
in the DC stage, good phase characteristics are maintained et the
damping factor rises to 45 (8Ohm).
The phono EQ stage is of the three-stage
NF type, dervied from the circuits of the [earlier] KA-6000.
The sharp 18db/octave two-position low filter uses a tantalum capacitor
with 1 mA dispersion current to avoid "thumping" when
switching the filter on or off.
The balance function has a "MIX"
position that, when enabled, makes the sound disappear when the
balance knob is tweaked to perfect stereo equivalence ; the "null
balance" switch comes handy when listening to monophonic sources.
I give up trying to make sense of the description of the elaborate
protection circuit -too incomprehensible to translate- but the six
blue LEDS must have cost a fortune in 1971 !
The
numbers to the right indicate :
1. Power block
2. Complementary-symmetry driver
stage
3. Tone control block
4. 5-gang volume control
5. &
6. High & Low filter blocks
7. Switch block
8. &
9. PNP & NPN power transistors
10. Equalizing amplifier
11. Power filter for preamp
section
12. Head-amp for low-level phono
cartridges
13. Power filters for main amp
14. Sealed power trafo.
The
mention of 4-channel compatibility (through and in/out loop) should
make this rare Kenwood of unknown
vintage a circa 1971 or 1972 vintage ; the layout is furthermore
somewhat close to the Supreme
Series which were launched in 1974,
seven years after the original Supreme
1 which gave indirect birth to a concurrent brand... Accuphase
!
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