TEST: SPL Gain Station

 Alright, I'll come clean! I, too, was once ignorant, almost foolish!

I vividly remember my early twenties when I was purely an instrumentalist. Various sound engineers would go on and on about their "outboard gear worship," which frankly got on my nerves.

Back then, there was endless chatter and debate about the appropriate input channel and the associated signal path. In my estimation at the time, all this 19-inch rack talk was completely over the top. I preferred to focus on my guitar, indulging instead in equally exaggerated discussions about the vibration characteristics of one-piece versus two-piece mahogany bodies. As I said, I had no clue...

It wasn't until years later, when I first occupied the responsible producer's chair and was often entrusted with the role of sound engineer, that I recognized the truly crucial importance of the first signal stage. The reality is, what you don't perfectly process or even mess up in the first recording stage, you won't be able to salvage even remotely in the subsequent stages with EQ, dynamics, or mixing.

Therefore, it indeed makes sense to acquire a preamplifier whose sole function is optimal gain boosting. The rest of the signal chain will thank you for it.

One of these purist devices is the SPL Gain Station, which, with its parallel transistor and tube concept, addresses the eternal dispute between semiconductor and vacuum tube with an additional option.

## Construction

Unlike many other preamplifiers, the Gain Station 1 doesn't come in a 19-inch rack format. Instead, the product was conceived as a mobile unit for space-saving transport in a 4.525-inch width and can be rack-mounted if needed by using four Gain Stations and an optionally available frame.

Due to its reduced size, the preamplifier can be used close to the microphone, for example, keeping cable paths short. Two sturdy carrying handles facilitate portability.

The Gain Station is a discretely built operational amplifier using Class A technology, where both output transistors always remain in a conductive state, as opposed to Class B technology, where each transistor handles a half-wave.

The tube type used is a 12AX7 LPS from the Russian tube specialist Sovtek.

SPL has placed particular emphasis on a high-quality power supply in the Gain Station, a point that is often undervalued. The transformer provides seven different voltages, all individually filtered and regulated.

## Rear Panel

The rear panel presents a spartan but functional mono setup. Besides the IEC power connector and the on/off switch, the Gain Station 1 features an XLR microphone input, a line jack input, a balanced XLR output, and a balanced jack output.

The Gain Station is also available with an integrated 24/96 AD converter module, which in this case also has additional digital optical and SPDIF inputs.

## Front Panel

The front panel of the Gain Station features 3 knobs, 6 mini-switches, and 9 LEDs, whose functions are as follows:

1. Clean Gain: Determines the pre-amplification of the Class-A transistor stage, with a control range up to +63 dB.

2. Tube Gain: Determines the pre-amplification of the tube stage. This stage is behind the transistor pre-amplifier stage, so the two gain values add up.

3. Output Level: Self-explanatory. Control range from -26 dB to +6 dB.

4. Source: Serves to select the input source (microphone or jack).

5. High Pass: Low-cut filter at 50 Hz with a slope of 12 dB (6 dB before and 6 dB after the Clean Gain stage).

6. Phase: Inverts the polarity of the microphone signal.

7. Imped.: Provides a pre-selection for the input impedance of the chosen microphone type (dynamic / condenser).

8. Phantom: Activates the 48V phantom power.

9. Limiter: Activates two different limiter types when needed (Peak: diode limiting for fast response and subtle level limiting, FET: field-effect transistors for the tube stage for compressor-like limiting).

## In Practice

Upon activating the device, the almost imperceptible level of background noise is very positive. Even with the controls turned up high, the noise level is so low that recording very quiet signal sources is not a problem.

First, the Clean Gain is subjected to a practical test. A very even pre-amplification and a soft reproduction without any coloration leave a very good impression. Even with explosive sounds or signal sources with high dynamics, the preamplifier has enough headroom to avoid "squashing" the signal or providing it with clipping.

However, the exact opposite is hoped for from a tube preamp, which ideally offers a powerful processing in terms of dynamics and saturation with a high degree of character to the signal source.

And lo and behold, Tube Gain doesn't disappoint and adds a very precisely dosable saturation to the fed signal, which will trigger real storms of joy among the followers of tube technology.

In combination with Clean Gain, almost all coloration and saturation levels are available, be it a tonally neutral booster amplifier whose use is ideally not noticeable, or a beefy, gritty tube preamp that comes close to a guitar preamp in terms of saturation and compression when fully loaded. Rarely have I heard a preamplifier that offers so much flexibility.

The tonal variety of the limiter located in the final stage is also very interesting. While the diode limiting indeed only eliminates small peaks and keeps the sound image very open, the FET switching process compresses the sum considerably.

The result actually reminds more of a compressor set to hard knee than the usually hard half-wave cut of a limiter. I really like it very much, although the factory preset might be set too tight for some users.

## Expanded Features and Applications

### Microphone Preamplifier

As a microphone preamplifier, the Gain Station 1 excels in its ability to capture the nuances of various microphone types. The selectable input impedance is particularly useful when working with different microphones, as it allows you to optimize the interaction between the mic and the preamp.

For condenser microphones, the high impedance setting ensures maximum voltage transfer, resulting in a clear and open sound. For dynamic microphones, the lower impedance setting can help to dampen resonances and provide a smoother frequency response.

The clean gain stage, with its impressive 63 dB of gain, is more than enough for even the most demanding low-output microphones, such as ribbon mics. The low noise floor ensures that even at high gain settings, you're hearing more of your source and less of the preamp.

### DI Box for Instruments

The Gain Station 1 also serves as a high-quality DI (Direct Input) box for instruments. This is particularly useful for bass players, acoustic guitarists, and keyboardists who want to send their signal directly to a mixing console or recording interface.

The tube stage can be particularly effective here, adding warmth and harmonic richness to direct sources that might otherwise sound thin or sterile. For example, a DI'd acoustic guitar can benefit from a touch of tube saturation to emulate the sound of a miked-up acoustic guitar amp.

### Reamping Tool

While not its primary function, the Gain Station 1 can also be used effectively in reamping scenarios. Reamping involves taking a recorded DI signal and sending it back through an amplifier or other processor to capture a new sound.

The Gain Station's line input can accept the recorded DI signal, and its tube stage can be used to add character before sending the signal to an amplifier. This can be particularly useful for adding analog warmth to digitally recorded tracks.

### Mastering Applications

Although primarily designed as a recording tool, the Gain Station 1 can find use in mastering applications as well. Its clean gain stage can be used for precise level adjustments, while the tube stage can add subtle harmonic enhancement to a full mix.

The limiter, particularly the FET-based option, can be used for gentle peak control during mastering. However, it's worth noting that the lack of precise threshold and ratio controls means it may not be suitable as a primary mastering limiter.

## Sound Character

The Gain Station 1's dual-path design allows for a wide range of tonal options. The clean gain path is remarkably transparent, adding gain without coloring the sound. This makes it ideal for situations where you want to capture the pure sound of your source, be it a high-end condenser microphone or a vintage instrument.

The tube path, on the other hand, can range from subtle warmth to rich, saturated tones. At lower gain settings, it adds a gentle thickness to the midrange and a slight softening of transients. As you push it harder, you'll hear more even-order harmonics, a slight compression effect, and that classic "tube sound" that can help sources sit better in a mix.

What's particularly impressive is how well these two paths integrate. You can blend them to taste, allowing for precise control over how much "character" you want to add to your signal. This flexibility makes the Gain Station 1 suitable for a wide range of sources and musical styles.

## Comparison with Other Preamps

When compared to other preamps in its class, the Gain Station 1 holds its own in terms of sound quality and flexibility. Its dual-path design sets it apart from many single-circuit preamps, offering more tonal options in a single unit.

Compared to vintage-style tube preamps, the Gain Station 1 offers cleaner, more controlled tube coloration. It's less about emulating a specific "classic" sound and more about providing a modern, versatile tool that can adapt to various recording scenarios.

Against solid-state competitors, the Gain Station 1 stands out with its tube option and its remarkably clean transistor circuit. Many solid-state preamps introduce some coloration, even in their "clean" mode, whereas the Gain Station 1's clean path is genuinely neutral.

## Integration in Modern Recording Setups

Despite being an analog device, the Gain Station 1 integrates well into modern, digital-centric recording setups. Its compact size makes it easy to keep on a desktop next to a computer and audio interface.

For those working primarily "in the box," the Gain Station 1 can serve as a high-quality front end, allowing you to capture the best possible signal before it enters the digital domain. This is particularly valuable in an era where many producers and engineers rely heavily on software processing; starting with a great analog sound can reduce the need for extensive digital treatment later.

The optional AD converter module further enhances its integration into digital workflows, allowing for a completely analog signal path up to the final digital conversion stage.

## Potential Improvements

While the Gain Station 1 is an excellent preamp, there are a few areas where improvements could be made:

1. Metering: The LED indicators provide basic level information, but a more detailed meter could be helpful for precise gain staging.

2. Output Transformer Option: Some users might appreciate the option of an output transformer for additional tonal shaping and galvanic isolation.

3. Variable High-Pass Filter: While the fixed 50 Hz high-pass filter is useful, a variable filter could provide more flexibility in dealing with low-frequency issues.

4. Stereo Linking: For stereo recording applications, the ability to link two units for matched stereo operation could be beneficial.

## Conclusion

The Gain Station 1 leaves an excellent impression! Both its concept and its sound are absolutely exemplary.

Due to the high quality of the individual components and the optional transistor or tube pre-amplification, the Gain Station offers a wide range of signal-shaping sounds.

Thus, the product can be used both as a pure microphone preamplifier and as a high-quality instrument preamp. Bassists, for example, can feed the signal directly into their power amp, while keyboardists or acoustic guitarists have a deluxe DI box with the Gain Station.

It's a highly flexible product that, due to its compact design, can fit almost anywhere. Highly recommended for both professional studios and home recording enthusiasts who want to elevate the quality of their recordings.

The SPL Gain Station 1 proves that sometimes, less is more. Its streamlined design and focus on core functionality result in a preamp that excels at its primary task: capturing and enhancing audio signals with clarity and character. Whether you're recording vocals, instruments, or full ensembles, the Gain Station 1 provides the tools to shape your sound at the source, setting the stage for a superior final product.