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Tape Head Demagnetizer Cassette :  (electronic schematic / circuit added 2/05)

Telephone Headgear:  A compact, inexpensive and low component count telecom headset can be constructed using two readily available transistors and a few other electronic components. Since the circuit draws very little current, it is ideal for parallel operation with electronic Telephone set. FAIR WARNING -THIS SITE HAS ANNOYING POP UP ADS. (added 4/02)

Telephone Headset Amplifier:  This circuit goes between a telephone and a headset. The project has a headset cord and plug (cut from a cheap cell phone headset) on the input and a suitable jack on the output. The speaker signal passes through this circuit, but the microphone signal is passed straight from the plug to the jack.  This circuit is specifically designed for ultra-low battery consumption. It uses a special control circuit (Q3, Q4 and Q5) to regulate the power amplifier’s quiescent current. Also, effort was spent to design an auto-on circuit (Q10 through Q14) that draws only 1.5 uA, yet has 15mV sensitivity.   Designed by Andrew R. Morris  (added 09/05)

Telephone Record Control (randy):  (circuit added 7/02)

Telephone Recorder (aaroncake):  This circuit lets you record your ph1-conversations automatically, notice that this circuit does not provide isolation between Telephone line and the recorder (added 4/02)

Telephone Recorder (tjacodesign):  This circuit automatically records all incoming and outgoing phone-conversations with an ordinary cassette or tape recorder. The circuit below distills the audio signal from the phone-line and automatically starts/stops the cassette recorder. (added 4/02)

Telephone Recording Circuit (epanorama):  How they work and some example  (added 4/02)

Telephone Tap #1:  Amplify or record a telephone call with the simple circuit shown. The 8-W secondary winding of a miniature transistor output transformer is connected in series with either of the telephone lines. The1000-W primary winding can feed either a cassette recorder or an audio amplifier. (added 2/03)

Terrestrial Set-Top Box (NTSC/PAL):  Intersil Application Block Diagram  (app note added 6/06)

Theremin Controller:  (electronic circuit added 4/05)

Theremin Model #145:  (electronic circuit added 7/03)

Three Level Audio Power Indicator:  Battery-operated Three LED display that connect it to loudspeaker output (added 9/04)

Tone Detector:  (electronic circuit added 7/03)

Tone Generator:  (electronic circuit added 7/03)

Top-Level OTL Tube Headphone Amplifier:  Shows my tube headphone amplifier designs for driving headphones with an impedance of 200 to 600 ohms (I am using these amplifiers with the Sennheiser 580, which has a 300-ohm impedance). The problem with many tube headphone amplifiers is the high output impedance and the low output current that decrease the sonic performance. I have analyzed many schematics, from a hybrid design with an E88CC voltage gain stage and a direct-coupled IRF610 MOSFET output stage to a design involving a 6080 or 6C33C-B as output stage in a cathode follower configuration.... (circuit design added 9/06)

Transistor Organ:  (electronic schematic / circuit added 4/02)

Truth About Vocal Eliminators:  Sometimes a vocal can be removed almost completely, but just as often the results are disappointing, just information without circuit diagrams (added 4/02)

Two Channel Noise Gate:  (circuit added 7/02)

Two Line Output Combiner:  Convert consumer equipment stereo signal to mono or combine audio signal from two different equipments to1-input (added 4/02)