The Warm Audio WA-412 provides 4 channels of classic American console preamps in a sleek 1RU design. This style of preamp is often referred to as "the sound of Rock n' Roll" for its BIG punchy low end and smooth open top end. The price/performance ratio of the WA-412 is almost unfathomable to the experienced studio engineer who has possibly paid much more for preamps of this style during their career. Featuring fully discrete socketed 6-pin opamps and custom wound Altran USA input and output transformers, the WA-412 leaves nothing to be desired. If you are looking for multiple channels of world class tone in an affordable package, the WA-412 is the right choice for you.The WA-412 has all of the features one would expect from this style of preamp... and more. Output Trim has been added to every channel for precise control and creative gain structuring. We also added a Tone switch (transformer input impedance) to each channel, which allows you to choose the warm and punchy classic console tone, or a more open & neutral sound.Warm Audio WA-412 Specifications:4 Channel Microphone Preamplifier + Instrument DIFully discrete, transformer coupled, through-hole component topologyAltran USA custom wound, premium input and output transformersX520 discrete op-amp in every channel, socketed for convenience. Can be user-replaced with most 6 pin, discrete op-amps forvarying flavor & tone65db of gainInputs - Microphone XLR & Active Instrument 2Meg ohm HI-ZOutputs - Transformer balanced XLR & TRSTONE button – Input impedance switches from 600 ohms to 150 ohms (affects the tone of both the mic and HI-Z inputs)-20db pad - pads both mic and instrument DI inputsSelf noise:< -90dB (nominal)Frequency response: 20hz to 20khz< +/-0.25dB (TONE button out), 20hz to 20khz +/-2dB (TONE button in)+48 volt phantom powerLED meteringOutput trim knob for precise level control and tone sculptingInternal power supply (grounded, 3 pin IEC cord) Warm Audio WA-412 4 Channel Discrete Microphone Preamp.