Summit Audio Model 2BA-221 Microphone Preamp and Line Module Operation Manual Summit Audio, Inc. P.O. Box 223306 Carmel, CA 93922 (831) 728-1302 email: sound@summitaudio.
Introduction DANGER! HIGH VOLTAGE IMPORTANT: Check the bottom sticker to make sure the 2BA-221 is manufacture for the voltage used in your country. This is done at the factory ONLY. Introducing the 2BA-221 continuously variable impedance microphone preamp from Summit Audio.
Introduction Carefully unpack the 2BA-221 and it’s power cord. Save the carton and packing material for possible future use. Before powering up the unit, read this manual and observe the cautions for HIGH VOLTAGE. Important Warranty Information For your 3 year warranty, register your 2BA-221 on line today at www.summitaudio.com.
Front Panel Front Panel Hi Z Input (Solid State) This input can be used to mix in a musical instrument or other high impedance signal. Line/Hi Z Input Gain Control This control simultaneously adjusts the solid state gain of the front panel Hi-Z input and the rear panel line input. Use more of this control for a cleaner, less vacuum tube sound. Adjust this control along with the Tube Output gain to get the proper output level and to get the desired sound.
Front Panel Tube Output Gain Control This control varies the tube output gain, including the XLR and balanced TRS outputs. Turn this dial up for more vacuum tube sound and to get more gain. Both the Line/Hi Z input and the Mic Preamp gain controls feed this control. For the most vacuum tube sound, turn this dial up to 2 or 3 o’clock and adjust the solid state input gain (Line/Hi Z or Mic) for the proper signal level. This control has no affect on the stacking output.
Front Panel Pad Switch This switch engages or disengages a –20dB pad to set the input sensitivity of the microphone input. If enough gain is available with your microphone, use with the pad set to –20 for quieter operation. Polarity Switch This switch inverts the polarity of the microphone input in order to compensate for out of phase equipment or wiring. +48V Phantom Power Switch This switch enables +48 volt phantom power to the microphone input.
Rear Panel Rear Panel MODEL 2BA-221 20W MAX SUMMIT AUDIO INC. CARMEL, CA USA OUTPUTS INPUTS STACK FUSE IN OUT +4 BAL. -10 BAL. INSERT IN MIC SUMMITAUDIO.COM A.C. Receptacle The 2BA-221 is factory wired for either 100, 115 or 230 Volts AC. Before connecting AC power make sure the 2BA-221 is wired for the voltage used in your country. +4 Balanced Output This is a balanced, low impedance XLR output connection compatible with professional recording and audio equipment.
Rear Panel 2BA-221 Signal Out Signal Return Tip To Input of Processor Insert The insert jack allows you to insert a processing device, such as a compressor, after the highpass filter and before the vacuum tube stage. This jack can also be used as another input or output. Refer to the block diagram on page 14. Ring To Output of Processor INSERT CABLE Signal is sent out on tip of plug and returned via ring of plug. When using the insert jack, a cable wired like the one shown above should be used.
Basic Operation Basic Operation Just Plug-in & Go 1. Plug your favorite microphone into the rear panel Mic Input jack, plug your instrument into the front panel Hi-Z Input, or your line level device such as a CD player into the rear panel Line Input jack. 2. Connect either the rear panel XLR or 1/4” Output to the input of your mixer or recorder. (Both outputs are balanced.) 3.
Applications Applications Amp & Direct Sound The 2BA-221 in conjunction with the Summit TD-100 provides you with a direct box and a mic preamp. This setup allows you to mix the sound of your guitar or bass amp with the direct sound of your instrument and sounds fantastic in both live or recording situations. Amp/Direct Channel Direct Out Input Line Output Input TD-100 2BA-221 10 Summit Audio, Inc.
Applications Using the 2BA-221 as an Acoustic Instrument Preamp Acoustic guitars and other instruments are often bi-amplified because of the superior sound reproduction obtained from using two transducers. The 2BA-221 is perfect for the job. Connect the pickup output of your acoustic instrument to the High Z input and connect a high-quality microphone to the Mic input. Adjust the input gain controls for the best tonal balance between the microphone and pickup.
Applications Using the 2BA-221 with the Summit TLA-50 Leveling Amplifier For a really sweet microphone channel, try using the Summit Audio 2BA-221 Mic and Line module in conjunction with the Summit TLA-50 Leveling Amplifier. To make this connection, you’ll need an insert cable with a stereo 1/4” phone plug such as the one described on page 8. Connect the two units with the insert cable as shown below. Adjust the input level on the 2BA-221 to get a proper signal level into the TLA-50.
Applications Using the 2BA-221 as an Instrument Preamp The 2BA-221 makes a great instrument preamp for guitars, basses, keyboards or whatever. In addition to the +4 Main Balanced Output, the Stacking Output and the -10 Main Output can be used to send the signal to the board, your amp or a headphone monitor amp. Turn up the Tube Output control for more tube sound, use the Solid State input gain for a cleaner sound.
Block Diagram Block Diagram Mic Input Variable Mic Impedance Filter Freq. Mic Pad Preamp ø -20 HP Filter In/Out Polarity Stack Input Stack Output Line/Inst. Gain Line Input (rear) Summing Amp Insert In/Out Hi-Z Input (front) XLR Output Output Level Tube Output Stage Peak Meters + 1/4" Output - The Impedance control of the 2BA-221 sets the input impedance of the microphone input. The Pad reduces the input level by -20 dB.
Block Diagram The summing amplifier drives the Stack Output, which is designed to feed the Stack Input of another 2BA-221. This signal is also sent to the Insert jack output, which can be used to insert another device, such as a compressor before the tube stage. The highpass filter has a variable cutoff frequency (20Hz -200Hz). This control is designed to remove low frequency rumble caused by stage vibration and other factors which may be picked up by the microphone.
Electrical Connections Electrical Connections Input Balanced 3-pin XLR Pin 1 Pin 2 Pin 3 Ground (+) Signal (-) Signal Balanced 1/4” jack Sleeve - - Ground Tip - - - - (+) Signal Ring - - - -(-) Signal Output 16 Summit Audio, Inc.
Specifications Specifications Circuit Topology High-voltage Class A Power Internal AC Supply 20 watts 115 volts 50 or 60 Hz Fuse size is .5 amp, slo-blo for 100/115 V Fuse size is .25 amp, slo-blo at 230 V Dimensions W: 8.5”, H: 1.75”, D: 8.5” (Two units fit side by side on a standard one-space rack shelf.) Weight 7 pounds (3.15 kg) Audio Specs For current audio specifications please contact Summit Audio at www.summitaudio.com.
Microphone Impedance Chart Microphone Impedance Chart Loading Impedance should be approximately four times the microphone output impedance listed below. Check the users manual on the respective microphone for exact figures. Brands and model numbers listed below are all copyright of their respective owners. This list is for reference only.
Microphone Impedance Chart Microphone Impedance Chart Brand Model Ω Model Ω Blue Blueberry 150 Brand N/DYM N/D767 300 Brand Evolution Model E609 350 Blue Mouse 150 N/DYM N/D468 150 Evolution E825 350 Blue Cactus 150 N/DYM N/D478 300 Evolution E835 350 Blue Kiwi 50 N/DYM N/D868 150 Evolution E845 350 Beyerdynamic MC740 150 RE RE27ND 150 Evolution E855 350 Beyerdynamic MC834 180 RE RE510 150 Evolution E865 200 Beyerdynamic MCE90 190 RE RE16 150
Summit Audio, Inc. P.O. Box 223306 Carmel, CA 93922 web page: www.summitaudio.com email: sound@summitaudio.com Please register on-line today at www.summitaudio.com. Thanks. 2BA-221 Op Rev.
