A Guide to Turntable Isolation Platforms: Materials and Benefits

When my good friend and fellow vinyl enthusiast, Gene DellaSala, called asking for help with an isolation table he had just received for review, I was intrigued and excited. Gene lives near Tampa, Florida, so I made the two-hour drive from Orlando to assist him and take a closer look at this new item. He wanted my input on setting up and tuning his analog system, particularly the stunning Marantz TT-15 turntable, designed by Clearaudio, which he had in his main office connected to a fabulous Anthem STR Preamp and RBH SFTR-AX Active speaker system.

My visit led to a deep dive into the importance of isolation in turntable setups. For those, like Gene and me, who are passionate about extracting every detail and nuance from vinyl records, isolation is not just a technical consideration—it's the foundation for achieving the purest sound. In this article, I will explore why isolation is crucial in turntables, the historical context behind it, the pros and cons, and how to achieve the best results using various materials and techniques.

The Historical Context of Turntable Isolation

Turntable isolation has been critical since the advent of high-fidelity audio in the mid-20th century. By the 1950s and 1960s, audiophiles began noticing that vibrations from the surface supporting the turntable could degrade sound quality. These vibrations, whether from footsteps, nearby equipment, or even the turntable's motor, could travel through the plinth and platter to the stylus, introducing unwanted noise and distortion, thus compromising sound quality.

As technology advanced, especially during the golden age of Hi-Fi in the 1970s and 1980s, manufacturers experimented with materials and designs to minimize vibrations. This led to the development of heavier, more robust turntables and the introduction of damping materials and suspension systems aimed at decoupling the turntable from its environment. This evolution in design marked a significant leap toward sonic purity—a pursuit that continues to this day.

The Impact of Vibrations on Audio Reproduction

As we tested different setups in Gene's office, it became clear how critical isolation is to sound quality. When a turntable isn't properly isolated, vibrations can interfere with the stylus's ability to accurately track the grooves of a vinyl record. These vibrations can enter the system in various ways:

1. Airborne Vibrations: Sound waves from speakers can cause the surface supporting the turntable to vibrate. These vibrations can be transmitted through the turntable’s structure to the stylus, resulting in feedback or distortion.

2. Structural Vibrations: Footsteps, nearby equipment, or even the turntable's motor can introduce vibrations into the system, causing the stylus to mis-track, leading to distortion or skipping.

3. Resonance: Every material has a natural resonance frequency. If the supporting surface resonates at a frequency close to the stylus’s tracking, it can amplify certain frequencies, distorting the sound and reducing clarity.

We noticed these issues firsthand when testing the Marantz turntable without proper isolation. The result was a loss of detail and clarity, with the stylus picking up vibrations unrelated to the music. This underscored the importance of appropriate isolation in preserving the integrity of the audio signal.

Advantages of Turntable Isolation

Our testing revealed several key advantages of turntable isolation:

1. Improved Sound Quality: Proper isolation allowed the stylus to track the record grooves without interference, leading to clearer, more detailed sound reproduction with better dynamics and tonal balance.

2. Reduction of Feedback: By isolating the turntable, we significantly reduced feedback risk, even when playing music at high volumes, allowing us to enjoy the music without distortion.

3. Increased Lifespan of Equipment: Vibrations can cause unnecessary wear on the stylus and other components. Effective isolation minimizes these vibrations, extending the equipment's life.

4. Enhanced Listening Experience: For us, the ultimate goal is to experience music as the artist intended. Proper isolation ensured that the playback was as faithful to the original recording as possible.

Disadvantages of Turntable Isolation

Despite its benefits, there are some drawbacks:

1. Cost: High-quality isolation solutions, such as dedicated isolation tables or platforms, can be expensive. For Gene, this was a factor to weigh against other potential system upgrades.

2. Complexity: Achieving effective isolation can be complex and may require experimentation with different materials and techniques, which can be challenging for those new to vinyl playback.

3. Space Requirements: Isolation platforms and tables can be bulky, taking up valuable space in a listening room. In Gene’s office, we carefully planed the setup to ensure everything fit without overcrowding.

4. Aesthetic Considerations: Some isolation solutions may not align with a listener’s aesthetic preferences. While function often trumps form in the pursuit of sound quality, aesthetics can still matter for those who value the look of their setup.

Achieving the Best Isolation: Materials and Techniques

Through our testing, we found that achieving optimal isolation requires careful selection of materials and techniques:

 1. Turntable Plinth Materials: High-density MDF, acrylic, and specialized composites are effective in absorbing vibrations and providing a stable platform for the tonearm and platter.

2. Turntable Platters: Heavy platters made from aluminum, acrylic, or glass provide mass and stability, helping to dampen vibrations. Mats made from cork, rubber, or felt further aid vibration reduction.

3. Isolation Feet: Turntable feet can be equipped with rubber or silicone dampers to absorb vibrations. High-end models often feature adjustable feet for fine-tuning isolation. The same principles apply when purchasing a quality isolation table.

4. Isolation Platforms and Tables: Dedicated platforms or tables are designed to decouple the turntable from its support surface. These often feature layers of materials with different damping properties, such as Sorbothane or constrained-layer damping materials. Some designs also incorporate air or fluid-filled chambers for additional isolation.

5.  DIY Solutions: For those on a budget, DIY options like placing a turntable on a heavy cutting board with rubber feet can be effective. Other options include using tennis balls cut in half or air-filled inner tubes to create a floating platform.

Conclusion

My trip to Tampa highlighted the importance of isolation in achieving the best possible sound from a turntable setup. By carefully selecting materials and techniques, we minimized external vibrations, ensuring that the stylus accurately tracked the vinyl grooves. The result was a cleaner, more detailed sound that faithfully represented the music.

While achieving effective isolation comes with costs and complexities, the benefits far outweigh the drawbacks for those, like Gene and me, who are dedicated to the pursuit of sonic purity. The evolution of turntable isolation reflects a continuous effort to refine and perfect vinyl playback—a journey every audiophile undertakes with passion and dedication.

Gene improved the isolation of his beloved Marantz TT-15S1 turntable by using an IsoAcoustics DECO isolation platform, achieving good results. However, further improvements could still be made by upgrading the feet, as discussed in this article.

References

1. Stereophile Magazine (2020). "The Art of Turntable Design: Plinths and Isolation."

2. Analog Planet (2021). "Vinyl Vibration: The Importance of Turntable Isolation."

3. What Hi-Fi (2019). "Understanding Turntable Isolation: History and Technology."