mirror of
https://github.com/problemkaputt/problemkaputt.github.io.git
synced 2024-05-13 10:09:21 -04:00
593 lines
26 KiB
HTML
593 lines
26 KiB
HTML
<HTML><HEAD>
|
|
<TITLE>Super Woofer SWF-3500 service info by nocash</TITLE>
|
|
<META NAME="GENERATOR" CONTENT="nocash XED editor">
|
|
<META NAME="Author" CONTENT="Nocash Martin Korth">
|
|
</HEAD><BODY bgcolor="#ffffff" text="#000000" link="#0033cc" vlink="#0033cc" alink="#0033cc">
|
|
<!--------------------------------------------------------------->
|
|
<TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
SWF-3500 Super Woofer</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
The Super Woofer is a neat black ghettoblaster in a beautiful black case
|
|
with a lot of square and some diagonal edges, manufactured in 1988 according
|
|
to the chip markings. One day, I found the Super Woofer on my staircase, asked
|
|
the neighbors where it came from, and got told that it's trash and that I can
|
|
have it. It wasn't trash, worked perfectly without even eating my tapes.
|
|
People who grew up with silver zeppelin shaped CD players may not like it.
|
|
Anyways about everybody who grew up in the eighties and sees it says:
|
|
Wow, that's cool.
|
|
<P>
|
|
Since I didn't find a schematic or service manual, here're the results of
|
|
my own research, with some potentially useful notes, pin-outs, and testpoints...
|
|
<P>
|
|
- Nocash
|
|
<P>
|
|
<A HREF="http://nocash.emubase.de/swf-3500.htm">http://nocash.emubase.de/swf-3500.htm</A>
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
Repair</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
<P><B>Rubber-Wheel and Drive Belts</B><BR>
|
|
The first thing I noticed when I got my SWF was that one the drives did
|
|
have the small rubber wheel missing; anyways, I found it inside of the
|
|
case, and justed needed to snap it back in.<BR>
|
|
As in all tape drives, drive belts tend to get worn-out after 10 years or
|
|
so, causing the drive to spin slowly, or even to eat the tape. In my SWF,
|
|
the belts are still okay (maybe they were already replaced some years ago),
|
|
anyways, in case of problems it may be a good idea to buy some new belts.
|
|
|
|
<P><B>Contacts</B><BR>
|
|
Next, the volume and equalizer regulators produced ugly scratch noise when
|
|
touching them, which I got fixed with some evil contact spray. It may be
|
|
also good to put some spray on the various switches; When I tried to measure
|
|
the Tuner/AUX/Tape contacts, I found only one 0 ohm contact, on the other
|
|
contacts I measured absurde values like 20 kilo-ohms (although the switches
|
|
still worked somehow). After some days the Deck-B output volume became
|
|
extremly silent and muffled, after putting some spray on the Play/Record
|
|
switch (S3) it seems to be working again (altough the problem may have been
|
|
caused by something else, that days the room-temperature dropped to 12'C, so
|
|
maybe the super woofer just got a cold).
|
|
|
|
<P><B>Plastic Clips</B><BR>
|
|
There are some elastic plastic clips that seem to tend to break: Two rather
|
|
unimportant clips that stabilize the big carrying handle in its vertical
|
|
position. And, four rather important ones:
|
|
Inside of each drive door, there seem to have been two plastic clips that
|
|
pushed-down the cassettes, but all of them seem to have been broken long ago.
|
|
In result, inserting tapes feels a bit as if the cassettes are a good bit too
|
|
small for the huge drive opening. And, during operation, the cassettes are
|
|
held down only by gravity... which is more at less working okay, but, if
|
|
gravity doesn't do it's job, then the tape isn't wound-up properly, and the
|
|
drive tends to eat the tape (eg. when turning the drive top-down, or when the
|
|
cassette isn't well inserted). So it may be recommeded to remove the drive
|
|
doors, and install some new plastic or metal clips inside of them.
|
|
<PRE>
|
|
#####
|
|
<------------ Insert Cas This Way
|
|
___-----__
|
|
/ ---___ X--- Screws
|
|
### / ------_X_ #### Drive Door Body
|
|
### | |####################|## --__ Elastic Foil
|
|
### | X|--##################|##
|
|
## \__/ #######################
|
|
#######################################################
|
|
|
|
#####
|
|
<------------ Insert Cas This Way
|
|
___
|
|
/ ---___ --__ Original Clip
|
|
### | #### Drive Door Body
|
|
### #######################
|
|
### #######################
|
|
## #######################
|
|
#######################################################
|
|
</PRE>
|
|
|
|
<P><B>White Noise Problem...?</B><BR>
|
|
In my SWF, I am having some white noise on Deck-B, it's mainly audible when
|
|
the tape is stopped (or even when no tape is inserted) (during playback, the
|
|
music is louder than the noise, so it isn't too annoying although the noise
|
|
is still there).<BR>
|
|
The noise disappers when Deck-B is deactivated (eg. when pressing Play/FF/Rew
|
|
on Deck-A). Aside from the noise problem, my Deck-B produces slightly deeper
|
|
sounds as than playing the same tape in Deck-A (of which, Deck-A tendencially
|
|
sounds better).<BR>
|
|
I am not sure if there's something broken in my SWF, or if that problem
|
|
appears to all SWFs - would be nice to know if it appears in other super
|
|
woofers, too!
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
Mods/Improvements</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
<P><B>AC Power Switch/Power Light</B><BR>
|
|
The original "power" switch in the SWF merely switches the 15V off (or
|
|
the 12V when using batteries), but keeps the transformator powered at 230V,
|
|
so it's permanently wasting a few watts of energy. To the worst, the SWF
|
|
doesn't have a Power LED, so it's easy to forget to switch off even the DC
|
|
part, and so, to waste a good bunch of watts.<BR>
|
|
To fix that problem, I've installed a nice red 230V switch with built-in
|
|
power lamp in the rear-plate.
|
|
|
|
<P><B>Less messy Wires</B><BR>
|
|
If you want to do any repairs, you'll probably curse the nasty wires. With
|
|
some efforts, the interiors can be made accessible in a more comfortable way:<BR>
|
|
- add a 6pin plug/socket in the wires that go to the rear-plate<BR>
|
|
- add a 8pin plug/socket in the wires that go to the front-plate<BR>
|
|
- replace W10,W11,W12 by longer wires<BR>
|
|
- add 2 contacts for injecting 12V and GND on the mainboard<BR>
|
|
For testing, it's best to remove the front-plate and rear-plate completely; the
|
|
12V/GND supply voltage can be injected from another external power-supply, and
|
|
audio-output can be tested via headphone socket, so the transformator and
|
|
speakers aren't needed at all.
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
Tape Drives</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
The dual-tape deck is pretty straight ahead, without any ferro/chrome/metal
|
|
detectors (there's only a record-lock detector), without auto-reverse,
|
|
and any without dolby noise reduction, but with Hi-speed dubbing.
|
|
And, most important, it's still having real mechanical Play/Stop switches,
|
|
so it's just fun to be able to actually <I>press</I> the buttons.
|
|
|
|
<P><B>Motor and Drive Belts</B><BR>
|
|
The dual-deck is having only a single motor shared for both drives, the
|
|
advantage is that it's cheap, and eventually ensuring that both drives are
|
|
spinning at exactly the same speed when copying one tape to another.
|
|
<PRE>
|
|
_______
|
|
| |
|
|
| Motor | |
|
|
____Brush____ |_______| ____Brush____|
|
|
Deck-A Wheel ' ||| | \___/
|
|
==============--------------------=== ||| Deck-B Wheel
|
|
|| Belt to Deck-A ===---------------------==============
|
|
|| | Belt to Deck-B ||
|
|
Axis
|
|
</PRE>
|
|
When replacing the belts, they should be arranged as shown above, ie. Belt-A
|
|
should be closer to the motor body, and Belt-B closer to the end of the axis.
|
|
|
|
<P><B>Play/Fast Forward/Rewind</B><BR>
|
|
Each deck has a switch that senses when PLAY/FF/REW is pressed. When the
|
|
switch on Deck-A is closed, then the output from Deck-B is muted. A rather
|
|
strange result is that one cannot rewind a tape in Deck-A while playing
|
|
another tape in Deck-B (however, it works vice-versa, rewind in Deck-B, and
|
|
play in Deck-A).
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
Disassembling the Case</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
The case consists of three components: The rear-plate, top-panel, and front.
|
|
|
|
<P><B>REAR-PLATE</B><BR>
|
|
Can be removed by loosening 6 long and 4 short screws.
|
|
The rear-plate contains the AC socket, the transformator, the battery box,
|
|
and the external antennae. The AC socket also contains a built-in switch that
|
|
activates the battery supply when the AC cable is disconnected.
|
|
|
|
<P><B>TOP-PANEL</B><BR>
|
|
The top panel isn't attached by any screws nor snap-ins. Once when the
|
|
rear-plate is removed, the top panel can be simply removed by pulling it to
|
|
towards the rear side; there's some soft/sticky glue (no hardenend glue) at
|
|
the front-end of the top panel, but that can be loosened quite easily.
|
|
The top panel contains the main electronics: The tape drivers, the 3 circuit
|
|
boards; cassette, tuner, equalizer, etc.
|
|
|
|
<P><B>FRONT-PANEL</B><BR>
|
|
Consists of the front plate (and side/bottom walls), and contains the
|
|
speakers: One set of large/tiny speakers (on each side, left and right),
|
|
one single bass speaker (in the center), and a microphone (as part of the
|
|
right speaker set, ie. underneath of the equalizers).
|
|
|
|
<P><B>CHANNEL SELECTION MECHANICS</B><BR>
|
|
The channel selector unit consists of a large black plastic block with
|
|
two large black wheels, located between the Tuner board and Equalizer board.
|
|
Underneath of the tuner board is a white lever with notches at both ends of
|
|
the lever, which rest on plastic edges inside of the horizontally arranged
|
|
wheel.
|
|
When removing and re-installing the tuner board: First remove BOTH the tuner
|
|
board and channel selector mechanics. Then fit the lever on the wheel, and
|
|
attach the tuner board to the mechanics with two screws. Then, attach the
|
|
channel mechanics on the equalizer board with another two screws, which can
|
|
be reached through holes in the tuner board.
|
|
|
|
<P><B>Drive Doors</B><BR>
|
|
Can be removed easily. Push the two vertical clips inwards that stop the
|
|
opened door after reaching the 45 degree positions. The door can be now
|
|
lifted up to a 90 degree position, and there it can be removed.
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
CIRCUIT BOARDS</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
The three circuit boards are:
|
|
|
|
<P><B>Mainboard (CR-X100-02)</B><BR>
|
|
Contains the AC-to-DC voltage converter, the audio amplifiers, the tape drive
|
|
electronics, and the AUX cinch sockets.
|
|
|
|
<P><B>Tuner-board (CR-X100-01)</B><BR>
|
|
Contains the tuner, and most important: The Tape/Tuner/AUX select switch.
|
|
|
|
<P><B>Equalizer-board (CR-X100-03)</B><BR>
|
|
Contains the equalizer, volume regulator, FMS-Switch and FMS-Led, bass-boost
|
|
switch, and the infamous power switch (which is barely a energy wasting
|
|
"standby" switch, since it doesn't disconnect the transformator). There's
|
|
also a tiny daughterboard with the headphone socket and two resistors on it.
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
WIRES</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
The circuit boards (and speakers and rear-plate) are interconnected with a
|
|
mess of about 50 single wires (rather than using a handful of flat-cables), to
|
|
the worst, the wires are soldered directly from one board to another (without
|
|
any plugs/sockets).
|
|
|
|
<PRE>
|
|
<B>Summary of all Wires</B>
|
|
W1 white 3pin (tuner to equalizer) (CURR-INPUT for OUTPUT)
|
|
W2 black 3pin (near supply) (mainboard to tuner) (TAPE for OUTPUT)
|
|
W3 gray 3pin (near cinch) (mainboard to tuner) (AUX-IN for OUTPUT)
|
|
W4 black 3pin (near supply) (tuner to mainboard) (CURR-INPUT for RECORD)
|
|
W5 brown 3pin (near motor) (mainboard to tuner) (TAPE for RECORD)
|
|
W6 brown 3pin (near cinch) (mainboard to tuner) (AUX-IN for RECORD)
|
|
W7 white 3pin (main-center) (equalizer to mainboard)
|
|
W8 N/A
|
|
W9 N/A
|
|
W10 orange 1pin stereo LED (tuner to equalizer board) (replace by longer wire)
|
|
W11 brown 1pin stereo switch (tuner to equalizer board) (replace by longer wire)
|
|
W12 red 1pin stereo switch (tuner to equalizer board) (replace by longer wire)
|
|
W13 white 2pin (mainboard to equalizer board) (mono/beatcut?)
|
|
W14 yellow 1pin BASS-SPEAKER minus (mainboard to boost-switch)
|
|
W15 green 1pin BASS-SPEAKER plus (mainboard to speaker)
|
|
W16 black 1pin BASS-SPEAKER minus (boost-switch to speaker)
|
|
W17 blue 1pin RIGHT (mainboard to equalizer)
|
|
W18 white 1pin LEFT (mainboard to equalizer)
|
|
W19 black 1pin (mainboard to equalizer)
|
|
W20 orange 1pin +6.8V (permanent) (near supply) (mainboard to equalizer)
|
|
W21 black 1pin GND (near MIC) (mainboard to equalizer)
|
|
W22 brown 1pin +6.8V (when CAS on)(near supply) (tuner to mainboard)
|
|
W23 orange 1pin +6.8V (permanent) (near supply) (mainboard to tuner)
|
|
W24 N/A
|
|
W25 black 1pin GND (near W20/W23) (mainboard to tuner)
|
|
W26 yellow 1pin cas speed... (mainboard-W26 to tuner-W27)
|
|
W27 white 1pin (mainboard-W27 to tuner-W26)
|
|
W28 green 1pin dubbing (equalizer board to tuner)
|
|
W29 magenta 1pin dubbing (equalizer board to tuner)
|
|
W30 magenta 1pin LEFT-SPEAKER plus (equalizer to speaker)
|
|
W31 blue 1pin RIGHT-SPEAKER plus (equalizer to speaker)
|
|
W32 black 1pin ONE-SPEAKER minus (equalizer to speaker)
|
|
W33 black 1pin OTHER-SPEAKER minus (equalizer to speaker)
|
|
W34 N/A
|
|
W35 N/A
|
|
W36 N/A
|
|
W37 yellow 1pin DECK-B Sense (mainboard to Play/FF/Rew Switch B)
|
|
W38 yellow 1pin DECK-B Sense (mainboard to Play/FF/Rew Switch B)
|
|
W39 magenta 1pin DECK-A Sense (mainboard to Play/FF/Rew Switch A)
|
|
W40 magenta 1pin DECK-A Sense (mainboard to Play/FF/Rew Switch A)
|
|
W41 orange 1pin MOTOR-Pin-B (mainboard to tape motor)
|
|
W42 red 1pin MOTOR-Pin-A (mainboard to tape motor)
|
|
W43 black 2pin MOTOR +/- Pins (mainboard to tape motor)
|
|
W44 gray 2pin DECK-B Erase Head (mainboard to drive head)
|
|
W45 gray 3pin DECK-B Play/Rec R (mainboard to drive head) (red=play, white=record)
|
|
W46 white 3pin DECK-B Play/Rec L (mainboard to drive head) (red=play, white=record)
|
|
W47 brown 3pin DECK-A Play Head (mainboard to drive head)
|
|
MIC gray 2pin Microphone (mainboard to front-plate)
|
|
J1 magenta 1pin (mainboard to mainboard) (W40 to elsewhere)
|
|
EXT.ANT red 1pin Antennae (tuner to rear-plate) (replace by longer wire)
|
|
NONAME 1pin brown (near W43) (mainboard to Power Switch)
|
|
NONAME GND 1pin black (near ...) (mainboard to tape drive body)
|
|
NONAME GND 1pin black (near ...) (mainboard to cooling plate)
|
|
~ REAR.red 12VAC 2x1pin to AC-DC converter
|
|
NONAME REAR.white 15VDC 1pin from AC-DC converter
|
|
NONAME REAR.brown to Power Switch (15VDC; or 12VDC when using batteries)
|
|
NONAME REAR.black GND (Battery Minus)
|
|
NONAME REAR.red 12VDC (Battery Plus)
|
|
</PRE>
|
|
|
|
<P><B>Mis-named wires</B><BR>
|
|
The L/R markings for the two AUX-IN wires (W3 and W6) are wrong (left and right
|
|
are vice-versa). W26 and W27 are somehow connected as crossed wires (ie. W26
|
|
on the mainboard connects to W27 on the tuner board, and W27 to W26).
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
CHIPSET</FONT></TD></TR></TABLE><BR>
|
|
<!--------------------------------------------------------------->
|
|
|
|
<PRE>
|
|
<P><B>Chipset Summary</B>
|
|
IC-1 N/A
|
|
IC-2 1x8 pins (LA3160 9A8) (Sanyo) (Deck-A Play)
|
|
IC-3 2x7 pins (Toshiba 8849U TA7658P M'SIA)(Deck-B Play/Rec)
|
|
IC-4 1x12pins (NEC JAPAN uPC1278H 8808D) (Left/Right Speakers)
|
|
IC-5 1x14pins (NEC JAPAN uPC1335V 8843B) (BASS Speaker)
|
|
IC-x 2x11pins (AN7025K .864) (Tuner board) (Tuner)
|
|
|
|
<P><B>IC-2 1x8 pins (LA3160 9A8) 2-Channel Preamplifier For Car Stereo (Deck-A Play)</B>
|
|
1 CH1 IN ;via 10uF to W47.L
|
|
2 CH1 NF
|
|
3 CH1 OUT
|
|
4 VCC (recommended 9V, typ 13.2V, max 18V)
|
|
5 GND ;(W47.Shield)
|
|
6 CH2 OUT
|
|
7 CH2 NF
|
|
8 CH2 IN ;via 10uF to W47.R
|
|
|
|
<P><B>IC-3 - Toshiba TA7658P - Dual Preamplifier for Tape Recorder (Deck-B Play/Rec)</B>
|
|
1 Power Supply (VCC, min 3V, max 16V) (6V in SWF, permanently on)
|
|
2 Buffer amplifier output (L)
|
|
3 Preamplifier output (L)
|
|
4 NC
|
|
5 Preamplifier feedback (L)
|
|
6 Preamplifier input (L) [right in swf]
|
|
7 ALC control output (Automatic Level Control)
|
|
8 Ground (ALC side)
|
|
9 Preamplifier input (R)
|
|
10 Preamplifier feedback (R)
|
|
11 Ground
|
|
12 Preamplifier output (R)
|
|
13 Buffer amplifier output (R)
|
|
14 NC
|
|
Above L/R are as suggested in the TA7658P datasheet
|
|
(in the Super Woofer, L/R are connected vice-versa).
|
|
ALC and Buffer-outputs are Record related (not Play related).
|
|
|
|
<P><B>IC-4 12pins (NEC JAPAN uPC1278H) (Left/Right Speakers)</B>
|
|
UPC1278H, Dual-Channel Audio Power-Output Amplifier
|
|
1 GND (IN)
|
|
2 OUT1
|
|
3 CAP1
|
|
4 FILTER.IN
|
|
5 IN1-
|
|
6 IN1+
|
|
7 IN2+
|
|
8 IN2-
|
|
9 CAP2
|
|
10 FILTER.OUT
|
|
11 OUT2
|
|
12 GND (OUT)
|
|
|
|
<P><B>IC-5 NEC JAPAN uPC1335V - Audio Power Amplifier (BASS Speaker)</B>
|
|
1 Output 1
|
|
2 Boot Strap 1
|
|
3 Compensation 1
|
|
4 Input 1
|
|
5 NFB 1
|
|
6 GND (Input)
|
|
7 Filter
|
|
8 Input 2
|
|
9 NFB 2
|
|
10 Boot Strap 2
|
|
11 Compensation 2
|
|
12 VCC (MIN 6V, TYP 12V or 15V, MAX 20V) (+15VDC in SWF)
|
|
13 Output 2
|
|
14 GND (Output)
|
|
|
|
<P><B>AN7025K - "AM Tuner/FM-IF + FM MPX"</B>
|
|
1 AM Mixer Input
|
|
2 AM Mixer Output
|
|
3 AM Mixer By-pass
|
|
4 AM IF Input
|
|
5 AM AGC
|
|
6 AM Detector Output
|
|
7 AM AF Input
|
|
8 Stereo Indicator
|
|
9 GND
|
|
10 MPX Pilot Detector Filter or Mono/stereo switch
|
|
11 VCO
|
|
12 MPX Phase Detector Filter or FM/AM switch
|
|
13 L-Channel Output
|
|
14 R-Channel Output
|
|
15 MPX Input
|
|
16 IF Detector Output
|
|
17 Quad. detector coil
|
|
18 VCC (min 1.8V, max 6.6V)
|
|
19 IF By-pass 1
|
|
20 IF By-pass 2
|
|
21 FM IF Input
|
|
22 AM Local Oscillator
|
|
</PRE>
|
|
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
Switches, Connectors, Regulators</font></td></tr></table><br>
|
|
<!--------------------------------------------------------------->
|
|
|
|
<PRE>
|
|
<P><B>Switches</B>
|
|
S1 tuner UKW/MW switch
|
|
S? Tape/AUX/Tuner switch (on tuner board) (see below for details)
|
|
S3 Play/Record Switch (on mainboard) (see below for details)
|
|
S4 FM Stereo
|
|
S5 N/A
|
|
S6 Dubbing
|
|
S7 Bass Boost
|
|
Sv (inside headphone socket)
|
|
Sw (inside AC socket at rear-plate)
|
|
Sx 15VDC Power Switch
|
|
Sy DECK-A Sense W39/W40 (when PLAY/FF/REW pressed)
|
|
Sz DECK-B Sense W37/W38 (when PLAY/FF/REW pressed)
|
|
|
|
<P><B>Regulators</B>
|
|
VR1 (on tuner board)
|
|
VR2 Speed LO (on mainboard)
|
|
VR3 Speed HI (on mainboard)
|
|
VR4 Volume Left (on equalizer board) (A50K) (mono)
|
|
VR5 Volume Right (on equalizer board) (A50K) (mono)
|
|
VR6 Equalizer 10kHz (on equalizer board) (8H0 B100K) (stereo)
|
|
VR7 Equalizer 3kHz (on equalizer board) (8H0 B100K) (stereo)
|
|
VR8 Equalizer 1kHz (on equalizer board) (8H0 B100K) (stereo)
|
|
VR9 Equalizer 300Hz (on equalizer board) (8H0 B100K) (stereo)
|
|
VR10 Equalizer 100Hz (on equalizer board) (8H0 B100K) (stereo)
|
|
|
|
<P><B>Connectors</B>
|
|
AC socket (with built-in DC battery switch)
|
|
headphone socket (with built-in switches, and built-in resistors)
|
|
AUX cinch inputs (for external CD player, or similar external stuff)
|
|
Battery Box (eight 1.5V cells) (ie. 12V DC)
|
|
|
|
<P><B>S3 (Play/Record Switch)</B>
|
|
Consists of 9 simultaneous switching two-position switches.
|
|
Each three pins are a separate two-position switch, with a common middle pin.
|
|
_______ ______ ______ ________ ________ ________ ________ ________ ________
|
|
| : : : : : : : : |
|
|
| 1 2 3 :4 5 6 :7 8 9 :10 11 12:13 14 15:16 17 18:19 20 21:22 23 24:25 26 27|
|
|
|_______:______:______:________:________:________:________:________:________|
|
|
|
|
1 GND (play) (not used)
|
|
2 GND (common) (low=enable)
|
|
3 ERASE (rec) (erase)
|
|
---------
|
|
4 .. (play) (?)
|
|
5 GND (common) (?)
|
|
6 .. (rec) (?)
|
|
---------
|
|
7 NC (play) (not used)
|
|
8 NC (common) (not used)
|
|
9 NC (rec) (not used)
|
|
---------
|
|
10 W46.L (play) (deck-b record left)
|
|
11 GND (common) (low=mute)
|
|
12 W46.R (rec) (deck-b play left)
|
|
---------
|
|
13 W46.R (play) (deck-b play left)
|
|
14 .. (common) (?)
|
|
15 .. (rec) (?)
|
|
---------
|
|
16 W45.L (play) (deck-b record right)
|
|
17 GND (common) (low=mute)
|
|
18 W45.R (rec) (deck-b play right)
|
|
---------
|
|
19 W45.R (play) (deck-b play right)
|
|
20 .. (common) (?)
|
|
21 .. (rec) (?)
|
|
---------
|
|
22 NC (play) (not used)
|
|
23 GND (common) (?)
|
|
24 .. (rec) (?)
|
|
---------
|
|
25 .. (play) (?)
|
|
26 .. (common) (?)
|
|
27 NC (rec) (not used)
|
|
|
|
<P><B>Input Select Switch (Tuner/AUX/Tape)</B>
|
|
Consists of 6 simultaneous switching three-position switches.
|
|
_____________________________________________ |
|
|
| : : | |
|
|
| A B C D :E F G H :I J K L | |
|
|
| 1 2 3 4 :5 6 7 8 :9 10 11 12 | |
|
|
|_______________:______________:______________| |
|
|
______________________________________________________| <--- board edge
|
|
|
|
1 W27/W28 (tuner) (W27, aka W26 at mainboard side)
|
|
2 W27/W28 (aux) (W27, aka W26 at mainboard side)
|
|
3 W26 white (common) (W26, aka W27 at mainboard side) (cas speed...)
|
|
4 W29 magenta (tape)
|
|
-----------------------
|
|
5 (tuner)
|
|
6 W3.R gray (aux)
|
|
7 W1.R white (common)
|
|
8 W2.R black (tape)
|
|
-----------------------
|
|
9 (tuner)
|
|
10 W3.L gray (aux)
|
|
11 W1.L white (common)
|
|
12 W2.L black (tape)
|
|
-----------------------
|
|
A (tuner)
|
|
B NC (aux)
|
|
C W23 orange (common) +6.8V (permanent)
|
|
D W22 brown (tape) +6.8V (when CAS on)
|
|
-----------------------
|
|
E (tuner)
|
|
F W6.R (aux)
|
|
G W4.R (common)
|
|
H W5.R (tape)
|
|
-----------------------
|
|
I (tuner)
|
|
J W6.L (aux)
|
|
K W4.L (common)
|
|
L W5.L (tape)
|
|
|
|
<P><B>AUX Inputs (Cinch)</B>
|
|
The left/right AUX inputs are connected with voltage dividers like so,
|
|
Cinch.L Cinch.R
|
|
| |
|
|
+----+----+ +----+----+
|
|
| | | |
|
|
[47K] [47K] [47K] [47K]
|
|
| | | |
|
|
W6.L ---+ +--- W3.L W6.R ---+ +--- W3.R
|
|
| | | |
|
|
[1.5K] [22K] [1.5K] [22K]
|
|
| | | |
|
|
+----+----+ +----+----+
|
|
| |
|
|
GND GND
|
|
W6 and W3 are then passed to the Input Select switch.
|
|
Mind that L/R are accidently named R/L on the mainboard.
|
|
|
|
<P><B>Tuner Left/Right-Output</B>
|
|
Tuner IC Tuner IC
|
|
Pin13 (L) Pin14 (R)
|
|
| |
|
|
o o
|
|
| wire | wire
|
|
o o
|
|
|__||__GND |__||__GND
|
|
| || | ||
|
|
| C34 2A135K | C33 2A135K
|
|
+| +|
|
|
=== C36 === C35
|
|
-| 1uF 10V -| 1uF 10V
|
|
__|__ __|__
|
|
| | | |
|
|
L10 ~ === C38 L9 ~ === C37
|
|
|__ __| 182J |__ __| 182J
|
|
| |
|
|
|__||__GND |__||__GND
|
|
| || | ||
|
|
| C39 2A222K | C40 2A222K
|
|
__|__ __|__
|
|
| | | |
|
|
R21 [ ] [ ] R78 R22 [ ] [ ] R79
|
|
150K |__ | 5K6 150K |__ | 5K6
|
|
| | | | | |
|
|
R35 [ ] | | R36 [ ] | |
|
|
1K5 | | | 1K5 | | |
|
|
GND | | GND | |
|
|
| | | |
|
|
Input Select Switch Input Select Switch
|
|
|
|
</PRE>
|
|
<!--------------------------------------------------------------->
|
|
<P><TABLE WIDTH=100%><TR bgcolor="#cccccc"><TD><FONT SIZE=+2>
|
|
Notes</font></td></tr></table><br>
|
|
<!--------------------------------------------------------------->
|
|
|
|
The audio signals are routed somehow like so:
|
|
<P>
|
|
Drive Head ---> Pre-Amp ---> Input Switch ---> Power Amp's ---> Speakers
|
|
<P>
|
|
For some reason, each audio input is passed <I>twice</I> to the Input Switch
|
|
(not sure, maybe one signal is for recording, and the other for output to the
|
|
speakers).<BR>
|
|
For speaker output, there are two separate Power Amplifiers, one for normal
|
|
left/right speakers (and left/right headphone), and one for the Bass speaker
|
|
(used when the Bass Boost switch is on).<BR>
|
|
When overloading the 6.8V supply (when dragging 2 Amperes or so), Q5 begins
|
|
to smoke. 6.8V isn't always that voltage, another day I've measured 7.4V for
|
|
whatever reason.<BR>
|
|
</BODY></HTML>
|