Related Manuals for Bandwidth Audio 288
Summary of Contents for Bandwidth Audio 288
- Page 1 288 Monaural Amplifier Owner’s Manual www.bandwidthaudio.com sales@bandwidthaudio.com...
- Page 2 With the volume turned all the way down, the bias should be set between: 60 - 65mA. This current can be read directly off of the 2 analog meters on the back of the amplifier after power on and warm up. See Section 3.3 – Biasing. 288 Monaural Amplifier Rev 1.2...
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Page 3: Amplifier Setup
Never turn on your amplifier without speakers connected to the proper output load impedance. Operation of the amplifier without a speaker load or open circuited loudspeaker voice coil can permanently damage the output transformers as well as other major components. 288 Monaural Amplifier Rev 1.2... -
Page 4: Powering On And Off
This amplifier is designed to drive a speaker load to its full rated output power based on typical line level input signals via the RCA connector on the back. Depending on the input source components, an additional preamp may be needed to achieve full output power. See Section 3.4 – Typical Specifications. 288 Monaural Amplifier Rev 1.2... -
Page 5: Controls And Layout
A stepped attenuator eliminates noise during rotation and also maintains volume balance between a pair of amplifiers driving separate speakers. Due to its construction, the volume knob will click into each slot, giving precise volume control. 288 Monaural Amplifier Rev 1.2... - Page 6 This can damage speakers rated close to the amplifier’s maximum RMS output power. 3. Power Switch The power switch is used to turn the amplifier on and off. On is in the up position, and Off is in the down position. 288 Monaural Amplifier Rev 1.2...
- Page 7 Use only 2.5 Amp Slow Blow Fuse 5. Mains Fuse . This fuse is in series with the mains current to protect the user and amplifier from various short circuit failures. 288 Monaural Amplifier Rev 1.2...
- Page 8 See Section 1.2 – Setting the Load Impedance. amplifier. 11. Input RCA line level input jack designed to accept audio signals from common See Section 1.4 – Input Setup. audio components. 288 Monaural Amplifier Rev 1.2...
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Page 9: Technical Information
Under extreme cases, tubes may become noisy. A crackling or rustling sound from your speakers will indicate that an immediate tube change is necessary. 288 Monaural Amplifier Rev 1.2... - Page 10 Preamp tube V2 contains two sections in a single glass envelope. These sections should be tightly matched for balance drive to the output tubes. All tubes from Bandwidth Audio are matched in this fashion. 288 Monaural Amplifier Rev 1.2...
- Page 11 If the current variation follows the position of the power tubes, then the tubes have become unmatched. If the tubes are new and the meters read significantly differently as described, then the set is not correctly matched. 288 Monaural Amplifier Rev 1.2...
- Page 12 This can be so excessive that the glass envelope of the tube melts! If red plating occurs, turn off the amplifier immediately and let it cool completely. Then turn it back on and quickly re-bias if the ammeters overshoot the 65mA bias target. 288 Monaural Amplifier Rev 1.2...
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Page 13: Typical Specifications
SNR 1-Watt into 8ohms (600-ohms source impedance, volume set to maximum) -93dB A-Weighted SNR 60-Watts into 8ohms (600-ohms source impedance, volume set to maximum) -110dB A-Weighted Gain 22dB Negative Feedback (Closed Loop Only) 15dB Input impedance 250K ohms 288 Monaural Amplifier Rev 1.2... - Page 14 4, 8, & 16 ohms Power Tubes 2x KT88 Preamp Tubes 2x 6SN7 Rectifier Tube GZ34 Power Consumption 150 Watts Dimensions 20” x 13” x 9.5” Actual performance will vary depending on vacuum tube quality. 288 Monaural Amplifier Rev 1.2...
- Page 15 V4_____________ Date: __________________ Bias Current: V3______________ V4_____________ Date: __________________ Bias Current: V3______________ V4_____________ Date: __________________ Bias Current: V3______________ V4_____________ Date: __________________ Bias Current: V3______________ V4_____________ Notes: ___________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ ___________________________________________________________________________________________ 288 Monaural Amplifier Rev 1.2...