SPL Audio Channel One MK3 Premiumfier

DISCRETE PREAMPLIFIER

Channel One Mk3 is equipped with one discrete preamplifier. The gain control can be used to adjust the preamplification. For microphone signals, a preamplification of up to 68 dB can be realized – so even really demanding microphones can show their qualities. The control range for line signals ranges between -20 dB and +16 dB. The control range for instrument signals ranges between -6 dB and +30 dB.

The Preamp Out picks up the signal directly after the microphone amplifier. This signal can also be recorded on a separate track in the DAW, for example, to be on the safe side. If it is noticed after a recording session that the singer was a little louder in the perfect take and therefore hits the compressor too hard, this incorrect setting can still be changed afterwards. The signal recorded for safety can later be played back into the Channel One Mk3 via the Line In and be processed there with Tube Saturation, Compressor or other tools.

TUBE SATURATION – MAGICAL TUBE SOUND

With this control the amount of tube saturation can be determined. The output level is accommodated automatically, in extreme settings the level increases by only 6 dB. Therefore decent to expressive harmonic distortions can be easily dialed in by turning just one knob.

Saturation effects are generated through the tube being pushed to and beyond its normal operating limits. In contrast to semiconductors, a tube thus pushed to such levels does not clip from a certain level, approaching more gradually its level limits and thereby producing its typical tonal result, which in audio signal processing can have such often profitable aural effects — on one hand (and depending on the amount applied), from subtle to extensive harmonic distortion and on the other hand, a compaction of the sonic event, that is, a limiting effect that exhibits a pleasant, rounded or soft sound. Acoustically and also in its range of applications this can be compared very well with tape saturation effects.

DE-ESSER

Unobtrusively and effectively, the Auto-Dynamic De-Esser removes distracting S‑sounds, in a mix or on vocal tracks, by detecting only the S‑frequencies, mixing them back into the main signal phase-inverted, and thus simply deleting sibilants in the original signal. The Auto-Threshold control maintains constant processing even as the singer’s distance from the microphone varies. The result is tonally neutral, unobtrusive and extremely effective. Even at high S‑reduction values, the de‑essing has no significant effect on the character and timbre of the voice.

TRANSIENT DESIGNER

With the Transient Designer it is possible to manipulate the envelopes of audio signals level-independently (no threshold!). Accelerate or slow down transients, lengthen or shorten sustain times – with just two controls: attack and sustain. All time constants are automated in a musical way and optimize themselves adaptively according to the characteristics of the input signal.

COMPRESSOR

The compressor is also extremely easy to operate with one knob only; its strength lies in its unobtrusive, musical operation. The Compression control can be used to set a threshold between 0 dB and -20 dB. The lower the threshold, the more the compressor works.

The Make-Up Gain control can be used to make up for the overall level reduction caused by compression. A value between 0 dB and 20 dB can be set by which the level is increased again after compression. With the help of the Gain Reduction display on the panel, the adjustment is very simple: if the maximum reduction value caused by the loudest part is e.g. -9 dB, the Make-Up Gain control should be set to values around +9 dB.

EQUALIZER

The center frequency of the half-parametric bass filter is set with the LMF control (low/mid frequencies). The adjustable frequency range is between 30 Hz and 700 Hz so that this filter covers a range of about 4.5 octaves, allowing it to be used from the deepest bass to the lower mid range.

The center frequency of the semi-parametric mid/high frequency filter is set with the MHF control. (MHF: mid/high frequencies). The frequency range can be set between 680 Hz and 15 kHz so that this filter covers a range of 4.5 octaves and can be equally employed in the lower mid as well as the high range.

The high frequency filter in the equalizer module is described as Air. A coil-capacitor filter with so called bell characteristics and a center frequency of 19 kHz comes into operation here. At this frequency the maximum possible accentuation is +10 dB, the maximum possible damping is -10 dB. The soft and natural tonal property, characteristic of the coil-capacitor filter, lends itself extremely well to provide clarity and air to vocals in the upper frequency range thereby improving their presence. On the other hand harsh sounds can be lent a more pleasant sound characteristic through damping.

PREMIUM LUNDAHL TRANSFORMERS

The Channel One Mk3 Premium includes an input transformer for the microphone inputs and an output transformer for the output Out 1. Transformers are used as an alternative to electronic balancing stages in the inputs and outputs. Transformers can be found in many classics of audio engineering. They make the bass and fundamental tines rounder and give it a little more punch. The high and overtone range sounds a bit silkier and more present.

The 2161 input transformer, which is specially designed for microphone inputs, provides an additional gain of up to 14 dB (depending on the microphone), which must then be added to the scaling. This relieves the microphone preamplifier. Since the transformer ratio passively increases the level, no noise is added. Therefore, the input transformer is more important than the output transformer in preamplifiers.

FEATURES:

• Discrete preamp section perfect for vocals or instruments
• Two microphone inputs and one line input on rear panel, and DI instrument input on front panel
• SPL’s Transient Designer for manipulating the envelopes of audio signals level-independently
• Premium Lundahl input and output transformers
• 3-band equalizer section for comprehensive tone shaping
• Tube saturation for expressive harmonic distortion at the trun of a knob
• Compressor/limiter controls provide unobtrusive, musical operation
• De-esser erases sibilants
• Headphone monitor stage
• Insert (send/return) for patching external effects

Achieving pristine, professional-quality sound in your recordings demands more than just a good microphone—it requires a superior microphone preamplifier that can bring out the fullest detail and warmth of your audio source. The SPL Audio Channel One MK3 Premiumfier answers this need by delivering exceptional sonic clarity, dynamic response, and tonal character, making it an indispensable tool for audio engineers, producers, and musicians who refuse to compromise on sound quality.

Many microphone preamps fall short when it comes to offering both transparency and musicality, often introducing noise or coloration that detracts from the original signal. The Channel One MK3 addresses these challenges by integrating a meticulously designed internal linear power supply with a shielded toroidal transformer. This ensures a stable and clean power source that minimizes electromagnetic interference and hum, resulting in a significantly quieter signal path. For you, this means capturing the purest representation of your instrument or voice without unwanted noise or distortion.

The power supply design supports multiple voltages critical to the preamplifier’s operation: +/- 15 V for analog audio circuits, +12 V for relays and LEDs, and a robust +250 V anode voltage for tube operation, complemented by a +12.6 V tube heating voltage. This careful voltage allocation translates into consistent, reliable performance and the rich harmonic content characteristic of tube amplification. The inclusion of phantom power at +48 V further enhances versatility, allowing you to seamlessly use condenser microphones without needing an external power source.

Connectivity is straightforward and professional with balanced analog inputs and outputs available via XLR and TRS jacks. The Channel One MK3 offers a maximum input gain of 21.5 dBu for microphones and 14 dBu for instruments, accommodating a wide range of source levels from delicate vocals to high-output electric guitars. Input impedances of 20 kΩ for line signals and 1 MΩ for instruments ensure optimal matching, preserving signal integrity and avoiding tone loss. The low output impedance of 100 Ω guarantees compatibility with virtually all downstream audio equipment, maintaining signal strength and clarity over long cable runs.

The frequency response of the Channel One MK3 spans an impressive 10 Hz to 100 kHz at -3 dB, far exceeding the audible range for humans. This extended bandwidth ensures that all harmonic content and subtle nuances are faithfully captured and reproduced, resulting in a sound that is both natural and immersive. Power consumption is efficient, capped at 20 W, and the unit supports selectable mains voltages of 230 V AC at 50 Hz or 115 V AC at 60 Hz, making it suitable for use in a variety of global studio environments without the need for additional adapters.

In practical terms, the SPL Audio Channel One MK3 Premiumfier is perfect for professional recording studios, live sound setups, and high-end home studios where audio fidelity is paramount. Whether tracking vocals, acoustic instruments, or electric guitars, this preamplifier elevates the captured sound, providing a warm, detailed, and transparent tone that enhances any recording or performance. Its robust build quality and reliable power supply design ensure long-term durability and consistent operation session after session.

Investing in the Channel One MK3 means you are choosing a preamplifier designed to meet the demands of discerning audio professionals. At a price of ₹297,060, it represents a premium solution that delivers tangible improvements in sound quality and operational stability. With this unit, you can confidently push your audio recordings to new heights, knowing that every detail from your source is preserved with accuracy and musicality. The SPL Audio Channel One MK3 Premiumfier is not just an upgrade; it’s a transformative tool in the pursuit of sonic excellence.