* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Single-Ended Audio Output Transformer
Spark-gap transmitter wikipedia , lookup
Wien bridge oscillator wikipedia , lookup
Integrating ADC wikipedia , lookup
List of vacuum tubes wikipedia , lookup
Power MOSFET wikipedia , lookup
Surge protector wikipedia , lookup
Standing wave ratio wikipedia , lookup
Schmitt trigger wikipedia , lookup
Transistor–transistor logic wikipedia , lookup
Wilson current mirror wikipedia , lookup
Operational amplifier wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Audio power wikipedia , lookup
Voltage regulator wikipedia , lookup
Current mirror wikipedia , lookup
Power electronics wikipedia , lookup
Radio transmitter design wikipedia , lookup
Opto-isolator wikipedia , lookup
Valve RF amplifier wikipedia , lookup
UBT-2 Single-Ended Audio Output Transformer Description The UBT-2 is a single-ended output transformer intended to be used in high-fidelity vacuum-tube audio amplifiers. It has a fairly high primary impedance making it suitable for use with classic triodes or pentodes. The UBT-2 is manufactured in the United States to high quality commercial standards. The core is grain-oriented M6 (Microsil®) silicon steel. It is protected from moisture by a full vacuum-impregnation with varnish. Every UBT-2 transformer is tested for: inductance, turns ratio, and high frequency response. Specifications Primary impedance: 4800 Ω Plate Tube Voltage* 45 250 V 300B 400 V 6CA7/EL34 450 V 50 450 V 845 550 V SV811-3 550 V SV811-10 550 V 440 V 811A† Plate Current 36 mA 65 mA 55 mA 55 mA 65 mA 82 mA 82 mA 95 mA Grid Bias -49V -86V -36V -84V -68V -100V -25V +24V Output Power 2.2 W 9.5 W 8.2 W 7.2 W 9W 9.5 W 4.5 W 9W * – Plate Voltage is the voltage between plate and cathode or filament. The total DC plate supply voltage should also include about 20-30 volts for voltage drop in the primary, and drop across the cathode bias resistor, if any. † – This is the transmitting type 811A run in class A2 mode with positive grid bias. The average grid current is about 23 mA. Secondary impedances: 4, 8, and 16 Ω Maximum DC primary current: 110 mA Maximum output power: 13 to 18 Watts (depending on minimum expected low frequency response). Primary resistance: 432 Ω nominal, 25° C Primary inductance: 29 Henries nominal (at 110 mA) Frequency and phase response: see graphs on next page. Size: 3.375" x 4.25" x 2.85" (95 x 108 x 86 mm) Weight: Approx. 5 lbs (2.25 kg) Application Information The UBT-1 transformer is a high-impedance transformer that is designed to be used with higher-voltage tubes. With such tubes, it is difficult to achieve the full power capable of the transformer, resulting in excellent bass “headroom”. A computer program was written to simulate a single-ended triode output stage. Using this program, operating points for the following triodes or triode-connected pentodes connected to the UBT-2 were determined (power output and bias points are approximate): The UBT-2 can also be used with conventional beam power tubes or pentodes. Several excellent-sounding guitar amps have been built using the 6V6GT and 6L6GC with the UBT-2. For best sound, it is recommended that the output transformer be driven by an impedance somewhat below the impedance that gives the maximum power output. The optimum output impedance for a triode power amplifier is highly dependent on the plate supply voltage, the optimum impedance rising as the voltage rises. It is tempting to use high plate supply voltages to achieve higher output power. The maximum recommended plate supply voltage is 600 volts. However, at this voltage, special care must be taken to avoid transient conditions that would cause high plate voltages, such as uncontrolled oscillations or running the amplifier without a load. Due to the high current flowing through the primary, it is normal for the UBT-2 transformer to become warm during operation. It is strongly recommended that a fuse www.one-electron.com UBT-2 data sheet rev 1.0 UBT-2 Single-Ended Audio Output Transformer be used in the B+ connection to the UBT-2 transformer. The relatively high voltage drop across the primary could prevent the AC line fuse from blowing if the output tube shorted or lost bias. A B+ fuse will help protect the transformer, as well as increase safety. A suggested value would be approximately twice the worst-case expected operating current. As with any output transformer, the UBT-2 should always have a load connected when driven. If there is no load and the output tube is over-driven, the high inductance of the primary will cause extremely high voltages to be produced, damaging either the output tubes or the transformer. +1 Even though the UBT-2 transformer can be the basis for excellent sounding amplifiers, it is meant to be used with relatively efficient speakers. If used with inefficient speakers (less than about 90 db/watt), used in a very large room, or used to play at deafening levels, a 10 to 15 watt amplifier will have insufficient power. That said, a single-ended triode amplifier, particularly without feedback, can sound much louder than its power ratings suggest. +50 Serial No. 0267 +40 AMPLITUDE (dB) -0 +30 +20 dB relative to 1KHz -1 -2 +10 PHASE SHIFT (degrees) -3 4 tap -4 -5 +0 16 tap -10 -20 2 -6 -30 2400 -40 -7 Black Red -8 -9 -50 8 tap Audio Precision System 2 -10 -11 20Hz 50 100 200 500 Phase shift in degrees +2 The maximum power available from the UBT-2 is primarily limited by core saturation at low frequencies. At 15 watts output, the core begins to saturate below approximately 50 Hz, although at the power levels normally acheived with the UBT-2, saturation occurs well below this. 1KHz 2K 5K 10K 20K -60 -70 50K 200KHz -80 Note: This response is for a typical transformer - the actual response may vary, especially at the high frequencies. 4.25 " (max) 108 mm (max) Blue Plate Brown 16 Ω Green Yellow Black B+ 8Ω 3.375 " 86 mm 4Ω 3.0 " 76 mm 3.75 " 95 mm 2.25 " 57 mm COM 2.75 " 70 mm Red Lead Lengths: 12 " (305 mm) Primary Leads Secondary Leads 2.85 " 72 mm 0.17 " (4.4 mm) dia. One Electron Transformers are exclusively distributed by: Antique Electronic Supply P.O. Box 1000 Yerington, Nevada 89447 USA www.one-electron.com 6221 South Maple Avenue Tempe, Arizona 85283 USA Tel: 1-480-820-5411 FAX: 1-480-820-4643 or 1-800-706-6789 www.tubesandmore.com