TEST: SPL Charisma 9733

 OK, guys, let's get straight to the point. Who among you has ever had the pleasure of recording an audio cassette on a tape deck?

Yes, the ranks thin considerably among the interested readers. Why do I start with such an analog introduction in the age of bits and bytes?

Well, unlike digital recording, where pushing the levels towards the 0 dB mark aims for maximum transparency and information density, analog recording has a highly extravagant life of its own beyond the (supposed) maximum level.

As an annoying teenager, I discovered more by accident that my vinyl to cassette transfers sounded significantly "better" when the first 1-2 red bars of the (then brand-new) LED meter lit up during loud passages (back when productions weren't yet dynamically over-compressed).

The saturation of the magnetic tape at the time led to an increase in loudness and a thickening of the signal, and young Axel had initiated his first homemade "mini-mastering process," not knowing what he was doing or why the result was so pleasing to the human ear.

Based on this analog sound processing and the associated signal alteration, recording technology has been trying for decades to achieve a fusion of the two preservation methods.

No one wants (or can!) do without the editing capabilities of digital technology nowadays, but any serious sound engineer moves close to audiophile euphoria as soon as they get to work on a valuable signal with correspondingly high-quality analog hardware, at least during the recording phase.

One product from this category is the Charisma from SPL, which generates the analog tape saturation effects and harmonic distortion behavior of tubes to breathe life into naturally sterile digital signals.

#### Construction

The Charisma 2 comes in a 1U rack format, with a depth of 23.7 cm and a weight of 3.5 kg.

Peering through the side vents, one can see that the Charisma doesn't rely on massive CPU logarithms for its processing function. Instead, two genuine preamp tubes (apparently of the 12AX7 type) do the work inside.

SPL secured the services of tube specialist Manfred Reckmeyer for this processor, who has earned an excellent reputation as an amp tuner among guitarists. He even completely rebuilt a '69 Marshall head for me in 1992.

Apart from the characteristically brass-colored front panel, the processor appears quite unspectacular visually, with each channel featuring only three knobs, two LEDs, and a bypass switch.

The functionality of the knobs in detail:

- **Drive:** Adjusts the drive of the tube electronics. The higher the value, the greater the number of harmonic overtones and the stronger the limiting effect.
- **Charisma:** Varies the saturation behavior of the tube. Adjustable from "Soft" (soft, slow, slightly damped peaking of harmonic structures) to "Hard" (rather late onset of harmonic distortion, but very direct at the level similar to a hard limiter).
- **Output:** Controls the output volume and serves to match the following device.

- **Process LED:** Lights up as soon as the device produces a certain percentage of harmonics.
- **Max LED:** Indicates the upper limit of processing.

On the back of the device, each channel features balanced inputs and outputs in the form of jack and XLR connectors. Additionally, there is a ground lift switch and an IEC power socket.

#### Practical Application

If you want to maximize the sound yield, you must accept that the "gods of saturation" have cursed you with the gift of a keen ear and intense training.

Especially sound engineers who haven't yet dealt with the analog life of their signals should take the time to familiarize themselves with the admittedly straightforward three knobs and the available output material.

You wouldn't believe how much the sound result varies only due to the increasing or decreasing harmonic waves and the set saturation behavior.

Moreover, the compression behavior changes radically. While the increase in the drive range can be compared to a (still dynamic) limiting, low charisma values produce noticeable compression effects that can generate characteristic pumping effects depending on the source material.

Depending on the dynamic behavior of the source material, you must decide whether you want to thicken the signal, compress it, or add distortion. It's essential to find the right balance here, keeping in mind how the signal should be placed in the mix later on.

Synthetic sounds from the keyboard sector benefit immensely from a high portion of archaic harmonic behavior. A "pig organ" in the old Deep Purple tradition really comes into its own here.

The Charisma sounds so fantastic that you might be tempted to compress every signal to the max, so that the material sounds excellent on its own but must be significantly lowered in volume in the mix due to its high sound density to avoid drowning out all other signals.

More than usual, a good producer is needed here, who has the necessary foresight of the final sound at the decisive moment and ensures a well-dosed, fine-tuning within the arrangement.

#### Extended Details

The Charisma processor is not just a simple tool but a versatile device that significantly enhances the sound quality of various instruments and recordings. Its ability to add warmth, character, and richness to digital recordings makes it an indispensable tool in modern music production. Here are some additional aspects and tips on how to get the best out of this device.

##### Integration in the Studio

Integrating the Charisma into your studio setup can be done in multiple ways. For example, it can be used on individual tracks during the recording phase, on buses for group processing, or even on the master bus for overall mix enhancement. Each approach has its own benefits:

- **Individual Tracks:** Applying the Charisma to individual tracks allows for precise control over each instrument's saturation and harmonic content. This can be particularly useful for vocals, guitars, and other lead instruments where character and presence are crucial.
- **Group Buses:** Using the Charisma on group buses, such as drum buses or background vocals, can glue the elements together, providing a cohesive and harmonically rich sound. This method helps in creating a unified sound for similar instruments or vocal tracks.
- **Master Bus:** Applying the Charisma to the master bus can add a final touch of analog warmth and cohesion to the entire mix. It’s a subtle but effective way to enhance the overall sonic quality of the mix, giving it a professional and polished feel.

##### Detailed Control of Harmonics and Saturation

The Charisma's ability to control the amount and type of harmonics and saturation is a key feature that sets it apart from other processors. Understanding how to use these controls effectively can greatly impact the final sound:

- **Drive Control:** Increasing the drive adds more harmonic distortion, which can make a track sound fuller and more vibrant. However, it’s essential to balance this to avoid unwanted distortion, especially on tracks that already have a lot of harmonic content.
- **Charisma Control:** This control adjusts the type of saturation from soft to hard. A softer setting can add a gentle warmth and roundness, ideal for subtle enhancements. In contrast, a harder setting can introduce a more pronounced and aggressive saturation, suitable for tracks that need more edge and presence.
- **Output Control:** Managing the output level is crucial to ensure that the processed signal matches the level of other tracks in the mix. This helps in maintaining a balanced and cohesive overall sound without having to make significant adjustments in the mix.

##### Practical Tips for Using Charisma

- **Vocals:** Adding a touch of Charisma to vocals can bring them to life, making them stand out in the mix. Start with a moderate drive and a soft saturation setting, then adjust to taste. This can help in achieving a warm and intimate vocal sound.
- **Guitars:** Electric guitars benefit greatly from Charisma's harmonic enhancement. For rhythm guitars, a higher drive and harder saturation can add punch and clarity. For lead guitars, a softer saturation can add sustain and smoothness.
- **Bass:** Applying Charisma to bass tracks can add depth and definition. A moderate drive with soft saturation helps in making the bass more prominent without overpowering the mix.
- **Drums:** On drum tracks, Charisma can add punch and cohesion. Use it on the drum bus with a moderate drive and hard saturation to glue the elements together, giving the drums a solid and unified sound.
- **Synths and Keys:** For synthetic sounds, Charisma can add a layer of analog warmth and complexity. Experiment with different settings to find the right balance that complements the electronic nature of the sounds while adding a touch of organic richness.

##### Advanced Uses and Creative Applications

The Charisma is not limited to conventional audio processing; it also opens up creative possibilities:

- **Parallel Processing:** Use Charisma in a parallel processing chain to blend the saturated signal with the dry signal. This technique allows for a subtle enhancement without losing the original character of the track.
- **Sound Design:** For sound designers, Charisma can be a powerful tool for creating unique textures and timbres. Experiment with extreme settings to discover new and interesting soundscapes.
- **Reamping:** Reamp tracks through Charisma to add a new dimension to previously recorded material. This can be particularly effective for tracks that were recorded digitally and need an infusion of analog warmth and character.

##### Conclusion

The Charisma is a versatile and indispensable tool for any serious producer or sound engineer. Its ability to transform digital recordings with analog warmth and character makes it a must-have in any modern studio. From individual tracks to group buses and the master bus, Charisma enhances the overall sonic quality, bringing life and richness to your recordings.

In summary, the Charisma from SPL is more than just an audio processor; it's a gateway to a richer, warmer, and more vibrant sound. Its intuitive controls and high-quality construction make it an essential addition to any studio, capable of elevating your productions to a new level of excellence. Whether you're working on vocals, guitars, bass, drums, or synths, Charisma offers the tools you need to achieve a professional and polishedsound. Let’s delve even deeper into the various aspects of the Charisma and explore how it can revolutionize your audio production workflow.

### Detailed Exploration of Features

#### Drive Control: Understanding Harmonic Distortion

The Drive control on the Charisma is pivotal in determining the amount of harmonic distortion added to your signal. This feature is particularly useful for adding warmth and depth to otherwise flat or sterile digital recordings. Here’s a breakdown of how to use it effectively:

- **Low Drive Settings:** Ideal for subtle enhancements, low drive settings introduce a gentle harmonic enrichment. This is perfect for acoustic instruments, vocals, and any track where you want to preserve the natural tone while adding a touch of warmth.
- **Moderate Drive Settings:** At moderate levels, the Drive control begins to add noticeable harmonic content, making the signal richer and more vibrant. This setting is excellent for electric guitars, bass, and drums, where a bit of edge can enhance the overall sound.
- **High Drive Settings:** High drive settings push the harmonic distortion to the forefront, creating a pronounced effect that can dramatically alter the character of the sound. This is useful for creative sound design, aggressive guitar tones, or any situation where you want to create a bold, impactful sound.

#### Charisma Control: Tailoring Saturation

The Charisma control allows you to fine-tune the saturation characteristics, providing a range of options from soft, smooth saturation to hard, aggressive distortion. Understanding how to manipulate this control is essential for achieving the desired sound:

- **Soft Saturation:** This setting is akin to the gentle compression and warmth of vintage tape machines. It is ideal for adding a touch of analog smoothness to vocals, strings, and other melodic instruments. The soft saturation ensures that the sound remains natural and pleasing while gaining subtle harmonic richness.
- **Medium Saturation:** With medium saturation, the Charisma starts to introduce more pronounced harmonic content. This is perfect for adding body and presence to instruments that need to stand out in the mix without being overpowering. Think of this setting as adding a bit of “glue” to your tracks, making them sit together more cohesively.
- **Hard Saturation:** At the hard end of the spectrum, the Charisma introduces a much more aggressive form of saturation. This setting is excellent for instruments and sounds that need to cut through the mix with authority. Use this for heavy guitars, bass, or any element where you want a strong, distinct presence.

#### Output Control: Balancing Levels

The Output control is crucial for maintaining the appropriate levels after processing. It ensures that the enhanced signal can be properly integrated into your mix without causing clipping or imbalance. Here’s how to use it effectively:

- **Matching Levels:** After adjusting the Drive and Charisma controls, use the Output control to match the processed signal level to the original. This helps in maintaining a balanced mix and prevents any unwanted jumps in volume.
- **Gain Staging:** Proper gain staging is essential to avoid distortion and maintain headroom in your mix. Adjust the Output control to ensure that the signal remains within an optimal range, preserving the integrity of the sound.
- **Creative Adjustments:** Sometimes, boosting or cutting the output level can be a creative decision. For instance, slightly lowering the output level after heavy saturation can help blend the processed signal more naturally into the mix.

### Practical Applications in Different Scenarios

#### Vocal Processing

Vocals are often the focal point of a mix, and using the Charisma on vocal tracks can make a significant difference. Here’s how to approach vocal processing with the Charisma:

- **Subtle Enhancement:** For a natural and intimate vocal sound, start with a low Drive setting and soft Charisma. This adds warmth and presence without altering the vocal’s natural character.
- **Modern Pop Vocals:** For contemporary pop vocals, where clarity and sheen are crucial, use a moderate Drive setting with medium Charisma. This adds just the right amount of harmonic content to make the vocals shine.
- **Rock Vocals:** For rock or aggressive vocal styles, push the Drive and Charisma controls higher. This introduces more harmonic distortion, adding grit and edge that complement the genre.

#### Guitar and Bass Processing

Guitars and bass are integral to many genres, and the Charisma can enhance their tones significantly:

- **Clean Guitars:** For clean guitar tones, use a low Drive setting and soft Charisma to add warmth and body. This makes clean parts sound fuller and more engaging.
- **Overdriven Guitars:** For overdriven or distorted guitars, increase the Drive and Charisma to medium settings. This enhances the natural distortion and adds richness without making the sound overly harsh.
- **Bass Guitars:** Bass guitars benefit from the Charisma’s ability to add depth and definition. Use a moderate Drive with soft Charisma to make the bass punchy and clear in the mix. For a more aggressive bass tone, increase the Drive and Charisma settings accordingly.

#### Drum Processing

Drums are the backbone of any track, and the Charisma can bring out their full potential:

- **Kick Drum:** Enhance the kick drum with a moderate Drive setting and soft Charisma. This adds punch and depth, making the kick more impactful.
- **Snare Drum:** For snare drums, use a medium Drive and Charisma to add body and snap. This helps the snare cut through the mix while retaining its character.
- **Drum Bus:** Processing the entire drum bus with Charisma can glue the elements together. Use a moderate Drive with soft to medium Charisma settings to add cohesion and warmth to the drum kit.

### Advanced Techniques and Creative Uses

#### Parallel Saturation

Parallel saturation is a powerful technique that combines the processed signal with the original, unprocessed signal. This approach allows for a more subtle enhancement while retaining the original dynamics and character:

- **Setting Up Parallel Chains:** Create a duplicate of the track you want to process and apply Charisma to the duplicate. Blend the processed signal with the original to taste.
- **Balancing Wet and Dry Signals:** Adjust the levels of the processed (wet) and unprocessed (dry) signals to achieve the desired balance. This technique is particularly effective for vocals and drums, where you want to enhance the sound without losing the original dynamics.

#### Creative Sound Design

The Charisma is not just for traditional audio processing; it can also be a tool for creative sound design:

- **Experimental Sounds:** Push the Drive and Charisma controls to their limits to create unique and experimental sounds. This can be useful for electronic music, film scoring, or any project that requires unconventional sounds.
- **Layering Textures:** Use the Charisma to add layers of texture to your tracks. For instance, apply heavy saturation to a copy of a synth pad and blend it with the original to create a rich, complex sound.

#### Reamping Techniques

Reamping is a technique where recorded tracks are played back through an amplifier or processor to add new characteristics. The Charisma is excellent for reamping digital tracks to infuse them with analog warmth:

- **Setup for Reamping:** Route your recorded track through the Charisma and back into your DAW. Adjust the Drive and Charisma settings to taste.
- **Enhancing Recorded Tracks:** This technique is particularly useful for tracks that were initially recorded digitally and lack the warmth and depth of analog recordings. Reamping through the Charisma can transform these tracks, adding a new dimension to the sound.

### Conclusion and Final Thoughts

The SPL Charisma is a remarkable tool that bridges the gap between digital precision and analog warmth. Its intuitive controls, robust construction, and exceptional sound quality make it an invaluable addition to any studio. Whether you are enhancing vocals, guitars, bass, drums, or experimenting with sound design, the Charisma provides the tools to elevate your recordings to new heights.

Investing time in learning and experimenting with the Charisma will undoubtedly pay off, as it becomes an integral part of your production workflow. The ability to add harmonic richness, warmth, and character to digital recordings cannot be overstated, and the Charisma delivers this with finesse and reliability.

In a world where digital clarity often comes at the expense of warmth and character, the Charisma stands out as a beacon of analog goodness. Its subtle yet profound impact on the sound quality makes it a must-have for any producer or sound engineer looking to achieve a professional and polished sound.