Wollensak T-1500 User manual

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Wollensak Model T-1500 Tape Recorder Service Manual
By Matthew S. Taylor. Last modified 5
January 2010.
Certain parts taken from:
Howard W. Sams & Co., Inc.
―Wollensak Models T-1500, T-1515-4,
T-1700, TS-1520.‖ Photofact® Set
564, Folder 15. Indianapolis 6,
Indiana: Jan. 1962.
---. ―Wollensak Model T-1500.‖
Photofact® Set 400, Folder 13.
Indianapolis, Indiana: May 1958.
Introduction
This manual is for the Wollensak T-
1500 tape recorder, which is designed
for operation on 120 VAC, 60Hz.
Models TS-1520 and T-1700 are
similar, differing only in the ability to
operate on different supply voltages. The TS-1520 model has an autotransformer which
allows it to operate on 220VAC, 60 Hz as well as 120VAC. The T-1700 model has a
vibrator inverter which allows it operate off of 12.6 VDC as well as 120 VAC.
The tape record is a complete self-contained recording and playback unit, with a self-
contained speaker. The audio output is also made available at the Preamp. Jack,
allowing it to be fed into an existing home music system, or an external speaker may be
connected to the External Speaker Jack.
Versions of the T-1500
I have found there seems to be an ―early‖ and a ―late‖ version of the T-1500 chassis,
which differ slightly in their electronics. The ―early‖ chassis was made between
approximately 1958 and 1961, and the ―later‖ from 1962 onward. The date of
manufacture is stamped on the underside of the electronics chassis.
Although the main text of this manual refers to the later chassis, notes for the 1958
version may be found in the Appendix on page 32. In the text, sections that differ for
the two versions I mark with a ―§‖, so be sure to check the Appendix for them if you have
the 1958 chassis!

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Table of Contents
Wollensak Model T-1500 Tape Recorder Service Manual ................................................. 1
Introduction ........................................................................................................................ 1
Versions of the T-1500 ........................................................................................................ 1
Specifications....................................................................................................................... 6
Frequency Response........................................................................................................6
Wow & Flutter.................................................................................................................. 6
Signal-to-Noise Ratio ......................................................................................................6
Tape Speeds ..................................................................................................................... 6
Tape Required..................................................................................................................6
Playing Time .................................................................................................................... 6
Power Requirements .......................................................................................................6
Power Consumption ........................................................................................................6
Size ...................................................................................................................................6
Weight..............................................................................................................................6
Function of Controls, Indicators, and Switches ................................................................. 7
Power Switch ................................................................................................................... 7
Tone Control .................................................................................................................... 7
Volume Control................................................................................................................ 7
Function Keys .................................................................................................................. 7
Stop .............................................................................................................................. 7
Record .......................................................................................................................... 7
Play............................................................................................................................... 7
High-Speed Lever ............................................................................................................ 7
Instant Stop & Record Lock Lever ..................................................................................8
Record Level Indicator ....................................................................................................8
Record Mike/P.A.–Monitor Switch ................................................................................8
Speed Selector..................................................................................................................8
Index Counter ..................................................................................................................8
Purpose of Jacks on Rear ....................................................................................................8
Input Jack ........................................................................................................................8
External Speaker Jack ..................................................................................................... 9
Preamp Output Jack........................................................................................................9

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Operating Instructions ........................................................................................................ 9
Preparation ......................................................................................................................9
Recording with a Microphone ......................................................................................... 9
Monitoring ...................................................................................................................9
Recording from an External Source.............................................................................. 10
Tape Erasure.................................................................................................................. 10
Playback ......................................................................................................................... 10
Playback with External Amplifier.............................................................................. 10
Splicing & Editing .......................................................................................................... 10
Use as a Public Address System .....................................................................................11
Disassembly Instructions.................................................................................................. 15
To Remove Mechanism from Case................................................................................ 15
To Remove Amplifier from Transport Mechanism....................................................... 15
To Remove Amplifier Without Complete Disassembly ................................................ 15
Replacing Sound Head .................................................................................................. 16
Preliminary Tests .............................................................................................................. 16
Function Switch Explanation.............................................................................................17
Electrical Adjustments ...................................................................................................... 18
Head Azimuth................................................................................................................ 18
High Frequency Equalization Adjustment §................................................................. 19
Hum Balancing Adjustment.......................................................................................... 19
Bias Current Adjustment §............................................................................................ 19
Cleaning.............................................................................................................................20
Lubrication ........................................................................................................................20
Troubleshooting Mechanical Problems ............................................................................20
No Tape Drive in Play or Record...................................................................................20
Take-up Reel Does Not Turn Although Tape Feeds Past the Capstan ......................... 21
Take-up Reel Stalls in Playback or Record when Reel is Nearly Full........................... 21
No Fast Forward But Capstan Turns ............................................................................ 21
Fast Forward Stalls with Full Reel ................................................................................ 21
No Rewind But Capstan Turns...................................................................................... 21
Tape Overruns or Spills When Functions Are Changed ............................................... 21
Speed Irregularities (―Wow‖ & ―Flutter‖) ..................................................................... 21
Bottom Motor Shaft Pin Rubs Bottom Ventilating Grill...............................................22

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Insufficient Tape Take-up .............................................................................................22
Tape Squeal or Squeak ..................................................................................................22
Troubleshooting Electrical Problems ............................................................................... 22
Weak Playback Volume or No High Frequencies .........................................................22
Recorder Dead, Pilot Light Off ...................................................................................... 23
No Playback or Record ..................................................................................................23
Plays, But Does Not Record Or Records But Does Not Playback .................................23
Weak or Distorted Record, Playback of Prerecorded Tape Normal .............................23
Record Level Indicator Inoperative or Operation Defective ........................................24
Hum in Record or Playback...........................................................................................24
Weak or No Erase, Records Over Previous Recordings................................................24
Microphonic Noises.......................................................................................................24
No Sound, Neon Lamp Flashes with Signal..................................................................24
Excessive Tape Hiss....................................................................................................... 25
Electrical Components ...................................................................................................... 25
Tubes & Lights §............................................................................................................. 25
Capacitors §.................................................................................................................... 25
Resistors §......................................................................................................................26
Inductors & Transformers §.......................................................................................... 27
Speaker .......................................................................................................................... 27
Rectifiers ........................................................................................................................ 27
Fuse................................................................................................................................ 27
Switches §.......................................................................................................................28
Motors............................................................................................................................28
Mechanical Parts List ........................................................................................................28
Appendix: Early Version Procedures & Components......................................................32
High Frequency Equalization Adjustment (p. 20)........................................................ 32
Bias Current Adjustment (p. 20)................................................................................... 32
Electrical Components .................................................................................................. 32
Tubes & Lights (p. 26) ............................................................................................... 32
Capacitors (p. 26).......................................................................................................32
Resistors (p. 27) .........................................................................................................32
Inductors & Transformers (p. 28) ............................................................................. 32
Switches (p. 29).......................................................................................................... 33

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Specifications
Frequency Response
3¾ ips: 40–8,000 Hz ± 3 dB
7½ ips: 40–15,000 Hz ± 3 dB
Wow & Flutter
Less than 0.3% for both speeds.
Signal-to-Noise Ratio
Greater than 48 dB.
Tape Speeds
3¾ and 7½ inches per second.
Tape Required
Up to 7-inch reel, ―A‖ wound tape (shiny side out).
Playing Time
A 7-inch reel of 1-mil tape recorded on both tracks at 3¾ ips will play for 3 hours; other
tape lengths, thicknesses, and speeds are proportional.
Power Requirements
Model T-1500: 120 VAC, 60Hz.
Model T-1520: 120 VAC or 220 VAC, 60 Hz.
Model T-1700: 120 VAC, 60 Hz or 12.6 VDC.
Power Consumption
100 Watts
Size
Approximately 6½ inches by 10¼ inches by 11¾ inches.
Weight
T-1500: 20 pounds
T-1520: 22 pounds
T-1700: 26 pounds

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Function of Controls, Indicators, and Switches
Power Switch
Rotating the tone control a few degrees clockwise turns the tape recorder on,
applying power to both the amplifier and transport motor. Thus the motor is ready to
transport the tape immediately whenever the Play or Record keys are pressed or the
High Speed Lever actuated. When the tone control is turned to the ―Off‖ position, a tab
on the knob trips the transport mechanism, locking it in the ―Stop‖ position for storage.
Tone Control
Turning the knob further varies the tone. The ―Balanced Tone‖ setting emphasizes
very high and very low frequencies, the degree of emphasis varying with the volume
control setting, thus producing a response which closely matches the normal hearing
response of the human ear. The ―Bass‖ setting cuts high frequencies and emphasizes
low ones. The ―Treble‖ setting emphasizes high frequencies. The ―Hi-Fi‖ position
produces a response suitable for use with external amplifiers.
The tone control has no effect when recording.
Volume Control
This regulates the volume during both recording and playback, as well as adjusting
the signal level applied to the Preamp Output jack.
Function Keys
Stop
Cancels either playback or recording. Brakes are applied to the spindles, the tape is held
away from the head, and the function switch is put into the ―Stop‖ position.
Record
Before the record key can be pressed to begin recording, the record lock lever must be
pulled. This releases the brakes, holds the tape against the head using pressure pads,
pushes the pressure roller against the capstan (which moves the tape), and turns the
function switch to ―Record.‖
Play
Pressing the play key results in the same action as record, except the function switch is
put into the ―Play‖ position.
High-Speed Lever
Moving this lever to the right causes the tape to advance at a much higher speed than
that used during recording or playback. When this lever is moved to the left, tape is
rewound onto the supply reel. The high-speed lever can be moved when the recorder is

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in any function (Play, Record, or Stop) and the play or record keys will be automatically
released. When the lever is returned to neutral, the recorder is left in the ―Stop‖ mode.
Instant Stop & Record Lock Lever
The record lock lever is provided as a safety feature to prevent accidental erasure of
prerecorded tapes. It must be pulled towards the front of the recorder and held there
before ―Record‖ mode can be entered.
It also serves as an instant stop lever when the tape is in motion during record or
playback. Pulling the instant stop lever disengages the tape drive and instantly stops the
tape. The recorder returns to its previous operation when this lever is released.
Record Level Indicator
During recording, the left or ―Normal‖ half of the indicator flashes to indicate a
correct volume setting. The right or ―Distorted‖ half flashes if the volume setting is too
high. To present the volume level for recording before the record key is pressed, the
tone control should be turned to ―Treble.‖ However, after the record key is pressed, the
tone control adjustment has no effect. When playing prerecorded tapes, ignore the
flashing of this indicator.
Record Mike/P.A.–Monitor Switch
This is a slide switch mounted on the rear of the tape recorder. When the switch is in
the ―Record Mike‖ position, the speaker does not operate in both record and stop
modes. This is also true of any speaker which may be connected to the speaker output
jack at the time. When this switch is in the ―P.A.–Monitor‖ position, the speaker is
connected so that the recorder can be used as a public-address system, or so that
program material may be monitored as it is being recorded. This switch has no effect in
playback mode.
Speed Selector
The speed selector is mounted near the index counter at the left front of the tape
recorder, and sets the speed of the tape. The speed selected appears on the speed
selector dial in inches per second. The recorder does not need to be stopped to change
speeds. Rapid forward winding can be further accelerated by selecting 7½ ips.
Index Counter
The index counter can be set to zero by turning the knurled knob towards the rear of
the tape recorder. If the counter is zeroed when recording or playback starts, tape
selections may be indexed, thus providing quick and accurate replay or editing.
Purpose of Jacks on Rear
Input Jack
The input jack can be used to connect a microphone or external audio source to the
tape recorder. The proper input circuit is automatically selected by means of different

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plug lengths for each application. A short (1-inch) plug is used with the microphone and
a longer (1
316
-inch) plug is used for external audio sources (televisions, radios, &c.).
External Speaker Jack
An external speaker can be connected to the tape recorder through this jack. The
impedance of the speaker should be 6-8Ω. Accessories such as the TE-401 earphone or
headphones may also be used. The internal speaker is disconnected when a plug is
inserted into this jack.
Preamp Output Jack
The preamp output jack is provided for connection to an external audio amplifier,
bypassing the internal output stage and speaker. The output impedance is
approximately 33 ĸΩ.
Operating Instructions
Preparation
1. Connect the tape recorder to the proper power source using the cord provided.
2. Make sure the high-speed lever is in the center or neutral position.
3. Turn the recorder on by rotating the tone control a few degrees clockwise.
4. Threading the Tape
a. Press the stop key.
b. Place a full reel of tape (glossy side out, i.e. ―A‖ wind) on the left spindle.
c. Pull a length of tape off the supply reel and lower it into the threading slot.
d. Attach the end of the tape to the empty take-up reel.
e. Set the index counter to zero.
Recording with a Microphone
1. Insert the microphone plug into the input jack on the rear of the recorder.
2. Set the slide switch to ―Record Mike.‖
3. Select the desired tape speed.
4. If you wish to preset the record level, then:
a) Turn the tone control to ―Treble.‖
b) Adjust the volume control until the ―Normal‖ half of the indicator flashes.
c) No flashing should occur on the ―Distorted‖ half.
5. Pull back the Instant-Stop-Record Lock Lever and press the record key.
6. Release the Instant Stop Lever.
7. Recording will start.
8. To stop recording, press the stop key.
9. To rewind the tape, move the high-speed lever to the left.
Monitoring
The signal can be monitored during recording if the slide switch on the rear panel is set
to ―P.A.–Monitor.‖ However, care must be taken to keep the microphone away from the

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speaker, otherwise acoustic feedback may cause squealing. This hazard can be avoided
if earphones are used instead of the internal speaker. The earphones should be plugged
into the external speaker jack.
Also, before rewinding the tape, additional material may be recorded by turning over the
full take-up reel and placing it on the supply spindle.
Recording from an External Source
1. Connect the signal source to the input jack using an A196-13 Hi-Fi cable, or similar
cable with a long plug.
2. Proceed with steps 2 to 9 for ―Microphone Recording‖ given above.
Recordings can be made from external sources such as phonographs, radios,
televisions, or AM-FM tuners. If the external source has a level control for its output
jack being used, it should be set so that the tape recorder’s volume control setting will be
somewhere near its midrange for proper operation of the level indicator. Tone controls
and loudness controls on the external source should be set to a flat setting.
Tape Erasure
Whenever a recording is made, any previously-recorded material on the tape is
automatically erased before the new material is recorded. Erasing is performed only
when the recorder is set to ―Record.‖ Half of the tape is erased at a time. To erase
without recording new sound, turn the volume control down completely before entering
―Record‖ mode.
Playback
1. Thread the tape as described under Preparation Step 4, a-e.
2. Locate the desired starting point using the High Speed Lever.
3. Set the speed selector to the speed used when the material was recorded.
4. Push down the play key.
5. Adjust volume and tone as desired.
6. For dual-track recordings, do the following:
a) Turn over the tape at the end of the first track.
b) Put it on the supply on the supply spindle.
c) Rethread the tape and play as before.
Playback with External Amplifier
1. Connect the external amplifier to the preamp output jack on the back of the recorder
using a shielded cable such as Wollensak A196-13 Hi-Fi cable.
2. Set the recorder’s tone control to ―Hi-Fi.‖
3. Adjust the recorder’s volume until the ―Normal‖ side of the level indicator flashes.
4. Adjust the amplifier’s volume and tone controls as desired.
Splicing & Editing
Tape from a dual-track tape recorder may be edited only if one track has been
recorded or if the program on the other track is not wanted. Undesirable portions can
be cut out, announcements can be inserted between selections, and so on. Unused