Akai X-355 - CROSS-FIELD HEAD

3. CROSS- FIELD HEAD
GENERAL INFORMATIONS
Cross-field head crea tes a sensation in the tape recorder world by maki ng a wide range of recording which has never been h ea rd before
any tape recorder.
Usi.ng this cross-field h
ead, Mode! X-355 provides a s urp rising reco rding performance (3 0-24,000 eps at a t ape speed of 7-l/ 2 ips and
' 0-18,000 eps
at 3 -3 / 4 ips).
vVhat is superior
abou t cross-field recordin g? How does it differ fr om typi ca l reco rding methods as f ar as construc ti on is concern ed?
On these, exp lana ti on is g iv en below in se qu en ces:
In the typi ca l recording system, the signal c urr e nt a nd th e bia s c urr en t are combined tog et her and app li ed to the recording h ead .
(Ref
er to Di ag ram 1. )
It is weil known that th e purpose of bia s c urr en t is recording at high se nsitivity with a signal applied on the tape, with no distortion
a
nd minimizing noi se generation.
However, the bias curr ent providing such an advantage also has an und esir ab le charac tor . That is, th e wide magnetic field of the bias
current affects the r ecorded signal, resulting in weakening or even erasing the signal. Thi s phenomenon is particularly noti ceab le at
h igh f req uencie s.
ln the cross-field system, the signal c urr e nt is app li ed to th e reco rdin g h ead while the bias c urr e nt is app li ed to the bias head.
These two heads are l oca t ed in different positions, as dete rmind int er -relatively, so that th e ma gnetic field of the bias w ill n ot affect
the signal recorded on
the tape, even when a sufficie nt bias is app lied. This a ll ows th e recorded signal to rem ain on th e tap e with
high fidelity.
Di
ag ram 1. Or dinary recording system Diagram 2. Cross-field recording system
Signal
_@_ ~: biao
Direction in
W hich tape is
t ransported .
__@_::~
({\)) Crossfield
~ Bias
head