Nakamichi System One
Over the years I’ve been looking for special items to complement my
collection of Nakamichi Cassette Recorders. The Nakamichi System One perfectly
fits this bill, but is not easy to come by. The System One comprises of
components of the 600 series of Nakamichi, a timer clock and a matching rack to
fit it all in. The idea of building a System One arose the day a friend brought
over a Nakamichi 610 pre amplifier as a gift. This little gem in the famous
wedge shaped housing sports a large number of specialized functions. The
complexity of this ‘system monitor console’ (official title) appeals to
professionals mostly. The 610 brought to me had been stored in an attic for
quite some time and looked like it. After a thorough cleanup and 
visual internal checkup
I connected this amp to the mains and one of the lights turned on. After
checking for any DC on the outputs I hooked up some gear and started a lengthy
investigation, finally concluding every function worked as it was supposed to
do.
Tuner
I put the 610 alongside a 600 already in my possession and enjoyed this
set’s intriguing form and functions.
Years later a friend informed me of the sale of an 630 tuner-preamp with 600
cassette player combination. This sale covered the set, and although a second
cassette deck was not high on my list, the set’s price motivated the purchase
of this rare tuner, appearing to function well.
4 wedge shaped pieces aside each other is a very nice line up and I put
this in the center of my cassette decks collection, as the tuner-preamp and
master console together support 5 tape monitors and then some additional line
inputs. So most of my cassette decks could be hooked up to the 600 lineup. At
this time I started the quest for the missing pieces to complete the System One, including the mounting rack.
Power
Amp
Regularly checking internet offers led to a 620 power amp listed by a
nice fellow I had met 10 years ago when working for a Dutch audio magazine. The
slightly modified 620 in mint condition was sent to me in great working order.
This final step in the collection of the complete 600 line was important, as
correct working power amps of this type are difficult to get. They have a
tendency to selfdestruct, as I had experienced before, and probably are in the
audio graveyard mostly by now. With the 620 in place the quest for the System
One mounting rack really became valid, since the four future occupants were
waiting for application. A friend and Nakamichi guru was using a System One
timer clock DS100 as a clock on his work bench. Apparently the timer was not
working very well and he was easily persuaded in parting with this particular
item which rounded up the complement of a System One.
The Cabinet
I kept looking for System One mounting rack offers, and came across only
rare occasions. Valid offers (only a hand full in years of time) were traded
very quickly and were expensive. I was willing to accept any offer, but not at
any expense. Finally an offer from nearby popped up and immediately I opted for
the buy. It was an combined set offer of an 610 preamp (silver, not fitting the
color of the rack) and two 600 cassette players and the much wanted rack. The
owner was not able to complete the system, was not sure everything was in
working order and therefore decided to part with the lot, for a very reasonable
price. I was finally facing the disassembled rack at my home. The three
machines of this set (610 and 2 times 600) were all in working order, but the
rack missed the base frame and trolley wheels. I built the base myself and
repainted the top of the rack where the paint had suffered the most. The base’s
dimensions deviate from the original version. One reason being my choice of
material and strength needed for supporting the complete setup ( an odd 60 kg )
and the other reason is the solid appearance I wanted to create with the
massive bars the base is made of.
Cassette
Copy System
Since the base was built the idea was to set up the system and play some
music. Before I did built the complete system I decided to setup the rack and
mounted 4 samples of 600 cassette decks. This has given me opportunity to
generate this exceptional picture. I don’t know of any historical use or setup
of this type of cassette copying system, but I just like the looks of it:
Finally…
Obviously the goal was to construct the original System One setup and
the 4 cassette deck copying setup had to go. (Gone until I can get my hands on
a second rack…) The definite setup I tried to make as tidy as possible,
minimizing dangling cables as much as possible.
I tied all power cords down to 
one side of the
rack and made custom length cabling for all audio connections needed. I did not
hook up some 21 century, ultra high tech audiocable with superconductive
connectors but in stead choose a sturdy RG 58 cable with reasonable connectors
in correspondence to the day and age of the machines.
Loudspeaker
switchbox
One additional item of the system is rather special in itself. The Power
amp 620 has one set of loudspeaker terminals, but the preamp (!) 610 has a
output selector switch splitting the loudspeaker output three ways, delivering
a ‘multi room sound system’ feature ‘avant la lettre’. This is accomplished
with an additional switching box, powered by the 610, splitting up the single
output of the 620 by means of heavy duty relays. This outboard switching box is
titled the RM-610, accepts power and switching inputs from the 610 preamp, one
set of loudspeaker input from the 620 poweramp and outputs three sets of
loudspeaker cables. Shown together with the power amp and connecting cables
this unusual setup looks like this:
Afterwards I looked for and found some visually and soundwise matching
loudspeakers, the LyricAudio LS2. These Loudspeakers needed some care for the
bass units were defect and partly
replaced. After restoring the bass units in premium condition the results on
the System One are very fine indeed: