Constant-Voltage-6
©Rane Corporation 10802 47th Ave. W., Mukilteo WA 98275-5000 TEL 425-355-6000 FAX 425-347-7757 WEB rane.com
DOC 103210 3-16
Rane Constant Voltage Transformers
Rane offers several models of constant-voltage trans-
formers. The design of each is a true transformer
with separate primary and secondary windings – not
a single-winding autotransformer as is sometimes
encountered.
MA3 Transformers
The MA3 had a design change in February 2007 affect-
ing whether the transformers are mounted internally
or externally.
For MA3 amplifiers manufactured
after
February
2007, use the MT 6 rack panel, which can hold up to six
transformers.
For MA3 amplifiers manufactured
before
Febru-
ary 2007, transformers are mounted internally. If you
aren't sure, the older MA3 has six transformer mount-
ing holes above the input jacks. TF 410 transformers
are sold individually for either rack-mounting or direct
mounting inside the MA3 chassis.
TF 410 rated 40 watts, 100 volts.
MT 4 Transformers
The MT 4 high performance toroidal transformers set
a new standard for wideband frequency response and
small size. MT 4 transformers come assembled in a 1U
rack-mount open tray chassis or individually as follows:
MT 4 Four channels: 100W, 100V or 70.7V (tapped sec).
TF 4 Rated 100W, 100V or 70.7V (tapped secondary).
KT 4 Open 1U tray chassis with connectors, mounts four TF 4
transformers.
Use MT 4 transformers with
any
standard power
amplifier and
any
combination of constant voltage
loads up to 100 watts to improve frequency response
and power handling. MT 4 transformers use premium
toroidal cores and windings to deliver excellent full-
power bass and a flat frequency response well above the
audio range. Distributions systems noticeably deliver
better audio fidelity. MT 4 transformers are also small-
er and lighter than other distribution transformers.
For 25 volt audio distribution, the TF 4 can be used by
connecting the 25V loads between its 70V and 100V taps.
See the MT 4 Multichannel Transformer Data Sheet.
References
1
Langford-Smith, F., Ed.
Radiotron Designer’s Handbook, 4th
Ed.
(RCA, 1953), p. 21.2.
2
Earley, Sheehan & Caloggero, Eds.
National Electrical Code
Handbook
, 5th Ed. (NFPA, 1999).
3
See: Giddings, Phillip
Audio System Design and Installation
(Sams, 1990) for an excellent treatment of constant-volt-
age system designs criteria; also Davis, D. & C.
Sound Sys-
tem Engineering, 2nd Ed.
(Sams, 1987) provides a through
treatment of the potential interface problems.
4
Reproduced by permission of the author and Howard W. Sams & Co.
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RANE CORPORATION
MT 4
+
IN
OUT
– 100V 70V COM
+
IN
OUT
– 100V 70V COM
+
IN
OUT
– 100V 70V COM
+
IN
OUT
IN
OUT
IN
OUT
IN
OUT
IN
OUT
– 100V 70V COM
+ – 100V 70V COM
+ – 100V 70V COM
+ – 100V 70V COM
+ – 100V 70V COM
MT 6 rack panel, rear view, with six transormers installed.
