AMPEX 11013-1 Frequency Determining Unit Cat 800 C-201 27KC

( Brand: Ampex ), ( Manufacturer Part Number: 11013-1 ), ( Type: Record Equalizer ), ( Country Of Origin: United States )

Review AMPEX Vintage Series 800 Frequency Determining Unit Cat

The **Ampex 11013-1 800 Frequency Determining Unit (FDU) C-201, Cat. 27kC** is a meticulously engineered, high-precision frequency reference module designed for professional audio and broadcast applications where absolute accuracy and stability are paramount. Part of Ampex s legendary line of professional equipment, this unit serves as a critical component in studio environments, post-production facilities, and broadcast centers, ensuring synchronized timing, pitch consistency, and flawless synchronization across multiple audio channels or systems. Built to exacting standards, the 11013-1 operates at a nominal frequency of **800 Hz**, a standard reference tone used in professional audio workflows for calibration, monitoring, and synchronization purposes. Its robust construction and precision engineering make it ideal for environments where reliability cannot be compromised, such as in the synchronization of tape recorders, digital audio workstations, or broadcast systems where even the slightest deviation in frequency could introduce errors in timing or pitch.

The **C-201** designation indicates a specific model variant within the broader 11013 series, tailored for applications requiring **27 kC (kilocycles) of frequency stability**, a metric that underscores its ability to maintain an exceptionally tight frequency tolerance over extended periods. This level of precision is achieved through the use of high-grade quartz crystal oscillators and sophisticated temperature-compensation circuitry, which mitigate drift caused by environmental fluctuations. The unit s compact yet durable design ensures easy integration into existing setups, whether mounted in a rack or used as a standalone reference source. Its clean, unmodulated 800 Hz output is free from distortion, making it suitable for use in phase-locked loop systems, audio test signals, or as a master reference for other frequency-generating devices. Additionally, the **Cat. 27kC** classification signifies compliance with stringent industry standards for frequency accuracy, ensuring that it meets or exceeds the requirements of professional audio and broadcast specifications.

Beyond its technical specifications, the Ampex 11013-1 embodies the legacy of innovation and craftsmanship that defined the brand during its golden era. Originally developed for use in high-end analog recording systems, this unit remains a trusted choice for engineers and technicians who demand the highest standards of performance. Its reliability is further enhanced by Ampex s reputation for durability, with components designed to withstand the rigors of continuous operation in demanding environments. Whether used in a modern digital studio or a legacy analog setup, the 11013-1 provides a stable, unvarying reference that eliminates discrepancies in audio playback, editing, or broadcast transmission. For professionals who prioritize precision over convenience, this frequency determining unit is an indispensable tool a testament to the enduring value of analog excellence in a digital world.

### **Pros and Cons of buying a Ampex 11013-1 (800 Frequency Determining Unit, C-201, CAT 27kHz)**

#### **Pros**

1. **High Precision Frequency Control** The Ampex 11013-1 is designed for professional audio and broadcast applications, providing stable and accurate frequency reference for timecode, synchronization, and studio environments. Its use of a 27kHz reference (CAT 27kHz) ensures compatibility with legacy and modern systems requiring precise timing.

2. **Compatibility with Ampex and Broadcast Systems** This unit was originally developed for Ampex s high-end tape recorders and editing systems, making it a reliable choice for studios still using or restoring vintage equipment. It can also interface with other broadcast-grade gear that relies on 27kHz timecode or synchronization signals.

3. **Durability and Reliability** Ampex was a leader in professional audio equipment, and this unit is built to industrial standards. If properly maintained, it can last decades, making it a cost-effective long-term solution for critical applications.

4. **Use in Restoration and Legacy Workflows** For filmmakers, archivists, or broadcasters working with older Ampex tape machines (e.g., 2000 series, 3000 series, or 400 series), this unit ensures proper synchronization and timecode generation, which is essential for accurate editing and playback.

5. **Rare and Specialized Supply** Since Ampex equipment is no longer manufactured, finding a functional 11013-1 can be difficult. Owning one may make you a unique resource in niche markets where such equipment is still in demand.

6. **Potential for Resale Value** Well-preserved Ampex components, especially those in working condition, can hold value among collectors and professionals in the vintage audio market.

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#### **Cons**

1. **Obsolete Technology** The unit relies on analog and early digital synchronization methods that are largely replaced by modern digital interfaces (e.g., AES/EBU, MADI, or digital timecode). This can make integration with contemporary systems cumbersome or require additional converters/interface boxes.

2. **Limited Availability of Parts and Support** Finding replacement parts (e.g., capacitors, transistors, or the 27kHz crystal oscillator) can be challenging. Ampex no longer supports this equipment, and even third-party suppliers may struggle to source components. Repairing it may require reverse-engineering or sourcing from obsolete stock.

3. **Maintenance Complexity** Unlike modern plug-and-play devices, the 11013-1 may require technical expertise to troubleshoot or repair. Users without electronics experience may find it difficult to diagnose issues like signal drift, power supply problems, or oscillator failures.

4. **High Initial Cost (If Available)** Since this is a specialized, vintage unit, prices can be steep, especially if it s in good working condition. The cost may not be justified unless you have a specific, high-value application for it.

5. **Compatibility Issues with Modern Systems** Most current audio workstations, DAWs, or digital recorders do not natively support 27kHz timecode or synchronization. You may need to use adapters (e.g., converting 27kHz to LTC or word clock) to integrate it with modern gear, adding complexity and potential signal degradation.

6. **Energy Consumption and Heat** Older analog/digital hybrid units like this can draw more power and generate heat compared to modern low-power digital devices. This may not be an issue for studio use but could be a consideration for portable or space-constrained setups.

7. **Learning Curve** Operating and troubleshooting the unit may require familiarity with vintage broadcast protocols, timecode standards, and analog electronics, which could be a barrier for newer professionals.

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### **Conclusion**

The Ampex 11013-1 is a **highly specialized, precision-built unit** ideal for professionals working with **legacy Ampex equipment, film restoration, or broadcast applications requiring 27kHz synchronization**. Its strengths lie in **accuracy, durability, and compatibility with vintage systems**, but its **obsolete nature, maintenance challenges, and lack of modern support** make it a poor fit for general-purpose or contemporary audio workflows.

If you **absolutely need** this unit for a specific project (e.g., restoring Ampex tapes, maintaining a rare broadcast setup, or working in a niche where 27kHz is required), it remains a valuable tool despite its limitations. However, for most modern audio production, digital alternatives (e.g., timecode generators, word clock sources, or software-based sync solutions) are far more practical and cost-effective.

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### **Recommendation**

- You are working with **Ampex tape machines** (e.g., 2000, 3000, or 400 series) and require **27kHz timecode or synchronization**.

- You are a **collector or archivist** with the technical skills to maintain and repair vintage equipment.

- You have **no modern alternatives** and the unit is **essential for your workflow** (e.g., a critical restoration project).

- You are prepared to **invest in backup parts** or have access to someone who can service it.

- You are working in a **modern digital studio** where AES, MADI, or digital timecode are standard.

- You lack **technical expertise** to troubleshoot or repair the unit.

- You cannot justify the **high cost** relative to modern, more versatile solutions.

- You do not have a **clear, long-term use case** for it (e.g., a one-time project where alternatives exist).

- For **modern digital sync:** Use a **word clock generator** (e.g., Digico SD1200, Riedel CommLink) or a **timecode generator** (e.g., For-A T-7, Sony PCM-1).

- For **Ampex compatibility:** Look for **third-party 27kHz modules** or **converter boxes** that bridge legacy and modern systems.

- For **restoration work:** Explore **digital audio restoration tools** (e.g., iZotope RX, Adobe Audition) to minimize reliance on hardware.

In summary, the Ampex 11013-1 is a **specialized tool with a narrow but critical application**. Weigh its pros and cons carefully against your specific needs before purchasing. If you proceed, prioritize **condition assessment, backup parts, and technical support** to ensure longevity.

Details:

Tested and Working. Only items included in pictures are the sale. Please look at all photos before purchasing. This item was pulled from a working environment.

part #: 110131 price

• $84.99

specifications reeltapevintagego:

• brand: Ampex
• mpn: 11013-1
• type: Record Equalizer
• country of origin: United States

shipping reeltapevintagego:

• cost: $4.99
• transit: 3-7 Days
• type: Fixed
• class: Standard
• carrier: USPS
• service: USPS First Class

seller reeltapevintagego:

• rating: 99.3%
• city: San Diego, California
• # reviews: 13196

general reeltapevintagego:

• Vintage Electronics > Vintage Audio Video > Reel-to-Reel Tape Recorders
• condition: Used

returns reeltapevintagego:

• time: 30 Days
• method: Money back
• paid by: Seller
• policy: Returns Accepted

payments reeltapevintagego:

• wallet: Paypal
• credit card: Visa
• other

offer reeltapevintagego:

• sold: 0
• started: June 8, 2026
• options: Ship-to-home
• best offers: True
• availability: In Stock

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