SPL Audio GainStation 1 Mic & Instrument Preamp w/ 1090 AD Converter

About: SPL Audio GainStation 1 Mic & Instrument Preamp w/ 1090 AD Converter

Class A & Tube Microphone and Instrument Preamplifier

The GainStation 1 is a discrete high-end preamplifier that combines Class-A clean gain with high-sounding tube gain and operates with an operating voltage of 60 V.

Class-A meets Tube

The GainStation 1 is a hybrid preamplifier consisting of a discrete Class A transistor stage and tube stage. The hybrid design of the preamplifier combines the advantages of semiconductors (high dynamics with low distortion, low noise) with the musical qualities of tube sound (pleasant high/overtone spectrum, beautiful three-dimensionality).

The Class A transistor preamplifier is based on our DMPA operational amplifiers, which operate with an operating voltage of +/- 30 V.

The preamplifier has a Butterworth Hi Pass filter, polarity inversion, impedance selection, 48 V phantom power and a limiter.

Clean Gain

The Clean Gain stage is a balanced instrumentation amplifier built with our DMPAs (Discrete Mic Pre Amp, 60 Volt rail). 

In Class A mode, both end transistors always remain in a conducting state, thus avoiding crossover distortion.

With a slew rate of over 100 V/µs, it is capable of amplifying even fast details and high frequencies cleanly and with low distortion.

Tube Gain

The tube gain stage is equipped with a 12 AX 7 LPS. It impresses with good noise figures and an open and clear sound image.

As decoupling capacitor a WIMA MKP type is used, which is very generously dimensioned with 2.2 µF, in order to work clean and powerful also in the bass range. 

HiZ/Line Input

The instrument input is a discrete impedance converter that also operates in class A mode. The core is a low-noise field-effect transistor, which is ideally suited as an impedance converter due to its very high input resistance.

Input & Output Stages

The input differential amplifiers are constructed with closely toleranced and thermally coupled transistor pairs.

The output stage operates as a current amplifier, which also offers pure class A operation with over 6mA quiescent current. DC voltage components are eliminated with an active servo circuit instead of coupling capacitors.

AD Input 2

The optional converter has two channels and can therefore convert an external mono signal in parallel with the GainStation 1.

Features

• Separately controllable transistor and tube preamplifiers
• The (switchable) tube stage delivers subtle to brutal tube saturation
• Only high-quality MKP film capacitors are used in the tube stage
• Peak/FET Limiter
• Polarity-reversal stage
• 48-Volt phantom power
• LED level indicator
• Switchable impedance adjustment for the microphone input (200 Ω, 1,2 kΩ & 10 kΩ)
• Discrete operational amplifiers in Class A technology instead of industrial ICs
• Amplifier slew rate of <100 V/µs
• Gas-encapsulated relays with gold-plated contacts
• Resistors with 0.1 % tolerance in the entire audio path
• Power supply with double shielding, each voltage with its own winding and regulation

AD Converter Module 1090 - Plug & Play Converter Module

This analog to digital 24 bit converter module offers an optional digital output for compatible SPL units.

The AD 1090 converter module offers an SPDIF output with both coaxial and optical connectors.

The module sports a 24-bit converter and supports sample rates up to 192 kHz.

Highly accurate quartz oscillators ensure a clean, low-jitter master clock.

The internal sample rate can be switched between 44.1, 48, 88.2 and 96 kHz. Other sample rates (32, 176,4 and 192 kHz) are set by external syncronization.

The converter can be synced to other digital devices via a SPDIF input. The internal oscillators are automatically disabled when an external clock signal is present to prevent interference.

Options for the GainStation 1

• Lundahl Transformers
  • The Sonic Aspects
    • 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.
    • We find transformers to be advantageous, especially for voices. For highest precision and speed in signal transmission (transient processing), however, electronic stages are better suited. The bottom line is that it is a question of taste and application.
  • In the Mic Preamplifier
    • In the case of preamplifiers or channel strips, 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.
    • However, it is only when both transformers are fitted that all positive sonic aspects are achieved – as well as increased operational reliability.

Specifications

• Line inputs & outputs; XLR (balanced) & TS Jack (unbalanced)
  • Maximum output gain - 30 dBu
  • Output impedance - 75 Ω
  • Frequency range (Clean Gain 30 dB, Tube Gain off) - 1 Hz – 310 kHz
  • Noise (A-weighted, Clean Gain 60 dB, Tube Gain off) - -67.2 dBu
  • THD + N (Clean Gain 24d B, Tube Gain off, Output +6 dB, 20 Hz -22 kHz) - 0.0005 %
  • Common mode rejection (Clean Gain 30 dB, Tube Gain off, 1 kHz, Input -30 dBu) - > 80 dB
  • Dynamic range - 130 dB
• Microphone Preamplifier, XLR (balanced)
  • Maximum input gain (Mic) - 17 dBu
  • Input impedance (switchable) - 200 Ω, 1.2 kΩ, 10 kΩ
  • THD + N (Clean Gain 23 dB, Tube Gain 1 dB, Output +6 dB, 20 Hz -22 kHz) - 0.032 %
  • Noise (A-weighted, Clean Gain 20 dB, Tube Gain 10 dB) - -86.4 dBu
  • Frequency range (Clean Gain 30 dB, Tube Gain 1 dB) - 1 Hz – 125 kHz
  • E.I.N. - -127.2 dBu
• Instrumenten Preamplifier, TS Jack (unbalanced)
  • Maximum input gain (Instrument) - 17 dBu
  • Input impedance (Instrument) - 1 MΩ
• Internal Linear Power Supply with Shielded Toroidal Transformer
  • Operating voltage for analog audio - +/- 30 V
  • Operating voltage for relays and LEDs - + 12 V
• Mains Power Supply
• Mains voltage (selectable) - 230 V AC / 50; 115 V AC / 60 Hz
  • Fuse for 230 V - T 315 mA
  • Fuse for 115 V - T 630 mA
  • Power consumption - max. 25 W
• AD 1090 Converter Module
  • Digital Outputs
    • Internal PCM sample rates - 44.1/48/88.2/96 kHz
    • Coaxial SPDIF (RCA), PCM sample rates - 44.1/48/88.2/96 & with ext sync 176.4/192 kHz
    • Optical SPDIF (Toslink F06), PCM sample rates - 44.1/48/88.2/96/with Glass fibre <1m: 176.4/192 kHz
    • 0 dBFS calibrated to - 15 dBu
  • Measurements
    • Frequency range (48 kHz) - 10 Hz – 22 kHz
    • THD + N (-1 dBFS, 1 kHz) - 0.0007 %
    • Jitter (Average, 700 Hz – 100 kHz) - < 300 ps
    • Stop band attention (48 kHz) - -105 dBu
    • Stop band attention (96 kHz) - -102 dBu
    • Dynamic range (A-weighted) - -112 dB
  • Power Consumption
    • Power consumption (+15 V, max) - 115 mA
    • Power consumption (-15 V, max) - 17 mA
  • Dimensions (WxHxD) - 3.94 x 1.06 x 3.0 inch (100 x 27 x 76 mm)
  • Weight - 0.15 lbs (68 g)
• Dimensions incl. feet (WxHxD) - 4.17 x 4.8 x 10.67 inch (106 x 122 x 271 mm)
• Unit Weight - 5.84 lbs (2.65 kg)
  • with AD1090 - 5.99 lbs (2.72 kg)