Universal Audio M610 Mic Preamp
Universal Audio M610 Tube PreamplifierThe Universal Audio M610 is a monophonic tube mic/instrument preamplifier. It’s great for tracking vocals, guitars and just about anything.This is mono version of the Universal Audio M2-610. This version comes with the classic sounding EQ that has two fixed frequency EQ switches. These can boost frequencies at 4k by +2dB or 8kHz at +4dB or OFF. There is also a low cut filter that is fixed at either 70Hz or 140Hz with a 6dB per octave high pass filter slope. This is somewhat of a relaxed slope and is used to remove the low frequency thumps and thuds before they hit the preamp stage. It also has a switchable cut or boost input gain: 1.5dB, 3dB, 4.5dB, 6dB, or 9dB. It has the same vibrant high-frequency response and deep, gorgeous low end that has graced countless recordings and continues Universal Audio’s reputation for sonic excellence.
The Universal Audio M610 is a MONO tube microphone preamp based upon the M.T. Putnam 610 console built back in the ’50s. Only 10 of these boards where manufactured. The 610 Console used rotary knobs and a modular design. It is known for it’s warm and unique sound. This board was used on many recordings by the Doors, Beach Boys, and Sarah Vaughan to name a few. Even Van Halen’s debut album was recorded on this console. Universal Audio has taken the tube mic preamp and put into a 19″ rackmount box.
This is a single channel preamp that can be used for Microphones, Instruments, and line level sources. It has two gain stages where each stage has a dual-triode tube that’s running in CLASS A mode single ended. The use of variable negative feedback helps to control the gain, distortion and frequency response of the unit.
The inputs and outputs are transformer coupled. The components used are of the highest quality and feature a double sized alloy core transformers with custom windings. The tubes used are hand selected and tested individually. Standard XLR input and output connectors are used and are located on the back panel of the rackmount box. There are three connectors on the back which are: XLR OUTPUT, XLR LINE INPUT, and XLR MIC INPUT. The OUTPUT is wired as Pin2 is positive and changes depending upon the polarity switch on the front panel.
The signal flow is: INPUT_SELECT ->TRANSFORMER ->GAINCONTROL ->LOW_CUT ->LEVEL_CONTROL ->HIGH_EQ->OUTPUT
The controls are rather simple but the sound is what makes this preamp so great. It has a simple EQ section that consists of a Low Cut and High Boost shelf filter. The Low Cut filter is switchable between 70Hz, 140Hz, and OFF. When the 70 position is selected it routes the signal through a +6dB per octave high pass filter. This is a gentle slope and is used to remove the low frequency rumble. It is -3dB point is at 70Hz. If the 140 position is selected then the same -6dB per octave slope high pass filter is used. The -3dB point is at 140Hz.
The Hi BOOST filters uses a toggle switch that has three positions: MID, OFF, and HIGH. When HIGH is selected a gentle shelf EQ is used that peaks at +4dB@8kHz. If the MID position is selected then this activates a shelf EQ that peaks a +2dB@4kHz while the OFF position bypasses the filters all together.
The 610 has phantom power built-in and you can turn it on using the toggle switch located on the front panel. Most condenser mics require phantom power from which to operate. The 610 is set at +48VDC which is the standard voltage that MOST condensers use. If you’re not certain about the voltage requirements of your mic please check the manual before connecting. If you aren’t using the Phantom power then turn it off. Also it’s best to turn down the console or preamp when turning ON the phantom power. This will help to avoid loud transients that maybe produced when it’s turned on.