Rare classic cassette deck: Nakamichi
250
Nakamichi is
known to be making the best cassette decks.
Period.
This is common
knowledge for the ‘audiophile’ society and in the eighties of the previous
century many home audio systems were proof of this statement. Audiophiles
painstakingly assembled their unique and diverse systems. Every component is
carefully selected from a wide variety of preferences, different for every
individual. When done, the addition of the cassette machine was rather simple;
buy a Nakamichi and the choice of the particular type largely dictated by the
available budget. Audiophiles turned out to be conformists is this area.
Simple.
Less simple is
the choice of mobile cassette player, in cars. Still, the brand Nakamichi is
associated with elevated quality and highly regarded by a select group of
enthusiasts. At least this can be seen from the
Back to Nakamichi
after this digression. In the seventies of the last century Nakamichi built
three cassette players with mobile applications in mind. The 550, 350 and 250
are the models referred here.
Those mobile
recorders run on 12 volt and the 250 is able to play tapes only, not record, so
typically usable in cars. But the 
different approach from Nakamichi is
shown by the size and unique design. For example, the large flywheels used can
hardly be confined to the space of the standard in dash radios. The resulting
level of speed stability was deemed essential to uphold the high quality mark
by Nakamichi.
During the seventies the standard sized
in dash car stereos were favored by most, and so not many enthusiasts chose for
the solution from Nakamichi. This is the reason, as far as I know, not to many
of those mobile cassette recorders found their way to the public. The smaller, simplest version is on topic
here; the play only Nakamichi 250. A sample of this type was brought to me. A
sample with a problem, as usual…!
The previous
owner sold this deck for it was after many years out of duty. It was not
checked whether is would still function. It was sent to me and appeared
reasonably mint, complete and very dusty. And it would not accept a cassette
tape as the eject button was not releasing the cassette bay.
Surprise
When opening
up, checking and cleaning this 250 I recognized the well known two head
mechanism, akin to the 500 and 550 already in my possession.
But? ... Akin
to the 500 series? I realized the erase head does not serve any purpose in a
play only deck like the 250. Nonetheless this deck is fitted with the erase
head in the designated spot, as is shown in the photos. (Drill down on
picture!) Why indeed? Looked at closely, the silvery connections at the back
are seen clearly. Looking again reveals the absence of wires at these
connections. The erase head is not connected to the electronics, because there
is no use anyway. Why this waste of
precious heads was chosen is up to anyone’s guess. Two possible suggestions;
1: The erase head sports a tape guide,
possibly required to maintain proper tape alignment in those decks. And no
alternative, like a dummy head, was developed to support the tape guide.
2: These head arrangements were used in four
Nakamichi machines at the time. Maybe economies of scale were justifying the use
of the same production line for all of them, as opposed to developing a
separate construction setup for the 250. This would result in a different and
extra manufacturing line up, requiring different machinery and doubling costs.
Evaluating the problem
Inside the
cassette deck proofed to be in original state and did not show too much wear.
Even the belts and rubber components were in good condition. The eject button
would not release the cassette door, but the door and bay were completely
operational.
I decided to
check the complete deck before connecting the 12 volt for a power up. The
mechanical parts were subject of attention. The eject function is catered for
by the stop button in this type of mechanism, a most common solution in that
era, before electronic logic was used to perform the tape function switching.
The idea behind the double function of stop was the elimination of the damaging
risk of tape eject while the heads were still inserted in the cassette.
Closely looking
at the internal mechanism discovered the metal rod attached to the plastic lock
of the cassette bay basis. Applying pressure on the eject button resulted in
bending this rod in stead of releasing the plastic lock. This lock was supposed
to rotate on a pivot but stayed put nevertheless.
Repair
The lock was
glued into position by the aged grease in the mechanism, something reminding me
of the pinch roller mechanism of the 480 series. (See common problems in this
site). Meanwhile I’ve grown accustomed to the transformation of seventies
Japanese grease into efficient glue in 2000 and later. The lock was coerced to
move with suitable force, patience and the addition of WD40 machine oil.
Eventually the cassette door was released and loosening up the mechanism
further brought back the original functionality.
Cleaning up and assembling the mechanics
brought back the 250 in full working order. No damage internally and externally
is apparent, except for a cigarette mark on top, harmless but visible.
Testing led to
the conclusion additional adjustment, electrical or mechanical, was not needed.
The functioning was flawless after all these years. (Obviously, bias and record
head adjustments are superfluous here.) This special Nakamichi will possibly
work for another 20 years! I save it with the 550’s and 350 in my collection.