PreSonus Studio Channel
Single-channel mic/instrument preamp with compression and EQ
Item # 861SDOCH | MFR # Studio Channel
This item is no longer available.
Our take on the PreSonus Studio Channel by Crutchfield's Eric Angevine
A versatile three-in-one channel strip
PreSonus calls this bad boy the Studio Channel, but they definitely designed it to go mobile for live performances as well. And you'll want it to be with you wherever you're working, because it can do so much, all in a single, rack-mountable chassis.
First, it's a high-output tube preamp that provides plenty of headroom and lots of tone for microphones and instruments. Second, it's a voltage control amplifier (VCA)-based compressor that offers quick, precise control over the dynamics of your incoming signal. Finally, it's a 3-band parametric equalizer, built to deliver smooth highs, solid lows and clear midrange. With XLR and 1/4" line outputs, you can connect the Studio Channel to almost any recording interface, amp, or PA system.
The PreSonus Studio Channel is a preamp with variable tube saturation, a precise compressor, and a three-band parametric EQ, all together in one go-anywhere unit.
The right tool for just about any job
What makes the PreSonus Studio Channel so handy? It's ready to deal with just about anything that comes your way. The XMAX™ Class A solid-state preamp features a built-in vacuum tube tone circuit — just twist the Drive saturation control to add the perfect amount of warmth and color. If your vocalist has some softer passages that get lost in the instrument mix, the compressor can even out the dynamic range so it's nice and audible throughout the mix. Then the equalizer can tweak the frequency response until everything sounds exactly the way you want it to. The owner's manual provides a detailed, easy-to-understand introduction to this jack-of-all-trades processor.
Thoughtful preamp design for clear sound
PreSonus understands how important the mic preamplifier is to the sonic quality of a recording. Microphone-level signals need to be boosted by a factor of nearly 400 before they can be converted to digital. Cheap, op-amp-based mic preamps can supply the boost, but the results may sound thin, noisy, or harsh. PreSonus's XMAX preamps use three core design elements to ensure maximum sound quality:
- High voltage: The XMAX preamplifier runs on power rails of 30V. Most off-the-shelf, op-amp-based designs run on power rails of 10V to 18V. Higher-voltage power rails deliver more headroom, deeper bass, and richer overall sound.
- Discrete components: For ultra-low noise and transparent sound, PreSonus uses transistors, resistors, and capacitors — no op-amps.
- Class A: Class A circuits eliminate switching distortion and deliver purer, clearer, and more musical results than the more typical Class AB designs found in many preamps.
Whatever you plug into the Studio Channel, expect to hear dynamic, low-noise sound with exceptional transparency.
- master level control
- rack-mountable, rugged steel chassis
- backlit VU meter and separate LED clip indicator
- sealed metal rotary controls
- frequency response: 10-50,000 Hz
Class A vacuum-tube preamplifier:
- gain control with +10 dB to +54 dB gain range
- variable tube drive control lets you blend in tube saturation to taste
- switchable 48V phantom power for use with condenser microphones
- 80 Hz high-pass filter lets you roll off low frequencies
- 20 dB pad accommodates extra hot signal levels
- polarity-reverse switch
Fully variable VCA compressor:
- attack, release, ratio, threshold, and gain
- auto attack/release switch
- soft/hard knee switch
- bypass switch
3-band parametric equalizer:
- mid-band gain, frequency, and Q controls
- low and high band gain and frequency controls
- low and high band shelving/peak switches
- switchable pre-/post-compressor
- bypass switch
Inputs and outputs:
- unbalanced 1/4" instrument input on front panel
- unbalanced 1/4" line input
- balanced XLR microphone input
- balanced 1/4" TRS line output
- balanced XLR line output
- 19"W x 1-3/4"H x 5-1/2"D
- weight: 5 lbs.
- warranty: 1 year parts and labor
- Our 60-day money-back guarantee
What's in the Box:
- Vacuum-tube channel strip Power supply
- Owner's Manual
- Warranty Card
Vacuum Tube Channel Strip: The Presonus Studio Channel combines tube pre-amplification, dynamics processing, and EQ into one slim-profile chassis. The Studio Channel is a professional channel strip combining Class A tube preamplifier, VCA-based compressor and 3-band parametric equalizer perfect for the professional and project studio. Great for all types of microphones, instruments, keyboards and synths; the Studio Channel has the sonic power and flexibility to achieve any tone - from luscious in your face vocals, crystal clear acoustic guitars, fat solid bass guitar, dynamic acoustic piano, cracking snare, punchy bass, or huge MPC tracks.
Class A Tube Preamplifier: The preamplifier stage of the Studio Channel is based on the award winning PreSonus BlueTube preamplifier with a high output 12AX7 vacuum tube operating on voltages double than all other preamplifiers in its class. It delivers high headroom and big tone, featuring dual control Gain and Tube Drive to create a wide range of sounds. The result is lots of headroom and big tone.
Tube Drive: The Tube Drive control increases the amount of signal routed through the 12AX7 vacuum tube. (The gain controls overall volume, whereas the drive controls volume routed through the tube.) The effect achieved ranges from subtle to extreme, depending on the setting being used.
- "Warming Up The Sound": This effect is achieved by adding in a small amount of Tube Drive (30% or less). It is especially desirable for vocals and electric bass. The resulting sound is richer and sweeter.
- "Overdriven Tube Sound": This effect is achieved by adding in 30-100% of Tube Drive. The more Tube Drive you add, the more overdriven the sound will be. This sound is extremely useful in creating distorted guitar and that authentic "blues harp" harmonica sound.
VCA-Based Compressor: VCA-based compressor is known for musicality and fast attack, with the ability to tame the fastest transients. From slap bass, to snare drum, to vocals, the Studio Channel's compressor allows you to record blazing-hot signals with total dynamics control. Its convenient Auto Attack/Release feature provides preset attack and release curves. The backlit VU meter can display gain reduction or output gain. Compressor controls include:
- Threshold: Sets the level at which compression begins. When the signal is above the Threshold setting, it becomes 'eligible' for compression. Basically, as you turn the Threshold knob counter-clockwise, the input signal is compressed (if you have a ratio setting of greater than 1:1). The threshold can be set from -40 to +20 dB.
- Ratio: Sets the compression slope. This is defined as the output level versus the input level. For example, if you have the Ratio set to 2:1, any signal level above the Threshold setting will be compressed at a compression ratio of 2:1. This simply means that that for every 1dB of level increase into the compressor; the output will only increase ½ dB, thus producing an attenuation of 0.5 dB. The Ratio can be set from 1:1 to 10:1.
- Attack: Sets the speed at which the compressor 'acts' on the input signal. A slow attack time (fully clockwise) allows the beginning envelope of a signal (commonly referred to as the initial transient) to pass through the compressor uncompressed, whereas a fast attack time (fully counterclockwise) immediately subjects the signal to the Ratio and Threshold settings of the compressor.
- Release: Sets the length of time the compressor takes to return the Gain reduction back to zero (no gain reduction). Very short Release times can produce a very choppy or 'jittery' sound, especially in low frequency instruments such as bass guitar. Very long Release times can result in an overly compressed signal (sometimes referred to as 'squashing' the sound). All ranges of Release can be useful at different times however and you should experiment to become familiar with the different sound possibilities.
- Gain Make Up: When compressing a signal, gain reduction usually results in an overall reduction of level. The gain control allows you to restore the loss in level due to compression and readjust the volume to the pre-compression level (if desired). You can adjust the Gain Make Up from -10 to +10 dB.
- Soft: The Soft button selects Soft Knee and Hard Knee compression curves. When this button is pushed in, Soft knee compression curves are used, otherwise hard knee compression curves are used. With Hard knee compression, the gain reduction applied to the signal occurs as soon as the signal exceeds the level set by the threshold. With Soft knee compression, the onset of gain reduction occurs gradually after the signal has exceeded the threshold.
- Auto: The Auto button places the compressor in automatic attack and release mode. The Attack and Release knobs become inoperative and a preprogrammed Attack and Release curve is used instead.
- EQ>Compressor: This button places the EQ before the Compressor in the signal path. By default the Studio Channel's signal path is as follows - Tube Pre to Compressor to EQ.
- GR>Meter: This button changes the VU metering to read the Gain Reduction of the Compressor rather than the output level of the Studio Channel.
Note: You are also able to bypass the compressor completely.
3-Band EQ: The custom-designed amplifiers in the Studio Channel's three-band EQ deliver sweet-sounding gain and cut for smooth highs; deep, solid lows; and clear midrange. The midrange band is fully parametric, with variable Q. The high- and low-frequency bands have Frequency and Gain controls, but fixed Q; and can be either shelving or peak bands. The EQ can be pre- or post-compressor, and you can bypass each stage independently.
- Low Band: Sets the Center Frequency of the "Q" or frequency range width of the Low Band EQ. You can adjust the center frequency from 20 to 300 Hz. By default, the Low EQ is set as a shelving EQ. When the peak button is enabled, the Low Band EQ becomes a standard peak equalizer with a fixed Q of 0.7. The level of the center frequency can be set between -10 and +10 dB.
- Mid Band: Sets the Center Frequency of the "Q" or frequency range width of the Mid Band EQ. You can adjust the center frequency from 200 to 3 kHz. The level of the center frequency can be set between -10 and +10 dB.
- High Band: Sets the Center Frequency of the "Q" or frequency range width of the High Band EQ. You can adjust the center frequency from 2 to 20 kHz. By default, the High EQ is set as a shelving EQ. When the peak button is enabled, the High Band EQ becomes a standard peak equalizer with a fixed Q of 0.7. The level of the center frequency can be set between -10 and +10 dB.
Note: You can choose to bypass the EQ entirely.
XLR & 1/4" Inputs/Outputs: With both XLR and 1/4" line outputs, you can connect the Studio Channel to almost any recording interface, amp, or P.A. system.
- Front-Panel Instrument Input: The 1/4" TS connector on the front-panel is for use with a passive instrument (guitar, bass, etc.). When an instrument is plugged into the instrument input, the microphone preamp is bypassed, and the Studio Channel becomes an active instrument preamplifier.
- Mic Input: The Studio Channel's XLR-type mic input can be used with all types of microphones including dynamic, condenser, and ribbon.
- Line-Level Input: The Studio Channel also features a balanced 1/4" line-level input to connect synthesizers, amp modelers, etc.
- Main Output: The Studio Channel features both a balanced 1/4" TRS and an XLR output for greater ease of connectivity to your mixer or amplifier.
Note: Active instruments are those that have an internal preamp or a line level output. Active instruments should be plugged into a line input rather than into an instrument input. Plugging a line level source into the instrument inputs on the front of the Studio Channel not only risks damage to these inputs but also results in a very loud and often distorted audio signal.
48V Phantom Power: The Presonus Studio Channel provides 48V phantom power for the microphone input.
Other Controls: The Studio Channel provides additional controls to tailor your sound.
- Phase Reverse: Reverses the polarity of the signal. Use the phase reverse when recording with more than one open microphones to combat phase cancellation between microphones.
- -20dB Pad: This button attenuates the input signal by 20 dB. The pad can be used to keep a hot signal from overdriving the microphone preamp
- 80Hz Roll-Off: The 80Hz button is a low-end roll-off filter. When
pushed in, the 80Hz button causes all frequencies below 80Hz to be
attenuated (dropped) by 12dB. This filter can be handy in live and studio
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