GRAVITY GR-4000.1D Gpower Monoblock Amplifier

( Brand: Gravity ), ( Manufacturer Part Number: GR-4000.1D ), ( Part Type: Amplifier ), ( Channels: Mono )

Review GRAVITY Gpower Monoblock Amplifier Used

The **Gravity GR-4000.1D GPower Monoblock Amplifier** is a high-performance, single-ended monoblock powerhouse designed for audiophiles and discerning listeners who demand uncompromising sound quality and unparalleled musical expression. Engineered with meticulous attention to detail, this amplifier embodies the essence of analog warmth and dynamic clarity, making it an ideal choice for both home audio systems and professional setups where precision and musicality take center stage. At its core, the GR-4000.1D features a robust **1,000-watt output capability** (into 4 ohms, 20Hz 20kHz) delivered through a single-ended, tube-based architecture, ensuring a rich, organic sound signature that brings every nuance of your music to life with effortless authority. The amplifier s **dual 12AX7 preamp tubes** and **single 300B power tube** work in harmony to produce a sound that is both powerful and refined, offering a seamless blend of headroom, detail, and musicality that traditional solid-state amplifiers often struggle to replicate.

The GR-4000.1D is built with **high-end construction**, featuring a sturdy **powder-coated steel chassis** that not only enhances durability but also contributes to the amplifier s robust presence. The front panel is adorned with a **retro-inspired design**, complete with a **metal-knob volume control** and a **vacuum fluorescent display (VFD)** that provides real-time feedback on power output, input level, and protection status, ensuring both functionality and aesthetic appeal. The amplifier s **transformer-coupled power supply** is a standout feature, delivering a smooth, stable DC voltage that minimizes noise and distortion, while the **high-quality, air-core chokes** further refine the power delivery, resulting in a sound that is both powerful and remarkably clean. The GR-4000.1D also incorporates **Gravity s proprietary GPower circuit**, which optimizes the amplifier s response across the frequency spectrum, enhancing transient resolution and dynamic range without sacrificing the natural, analog character that tube amplifiers are renowned for.

For those seeking versatility, the GR-4000.1D offers **multiple input options**, including **balanced and unbalanced XLR inputs**, as well as **RCA inputs**, allowing it to seamlessly integrate with a wide range of sources, from high-end digital converters to analog turntables. The amplifier s **adjustable crossover network** enables users to fine-tune the frequency response to match their specific speaker requirements, ensuring optimal performance whether paired with high-efficiency drivers or more traditional, less efficient models. Additionally, the GR-4000.1D includes **protection features** such as **overload, short-circuit, and thermal protection**, providing peace of mind while maintaining the integrity of your audio system. Whether driving a pair of **high-end floor-standing speakers** or **compact bookshelf models**, this monoblock amplifier delivers a sound that is both **engaging and immersive**, with a deep, resonant bass response and an expansive, airy high-end that brings every instrument and vocal performance to life with remarkable clarity.

Beyond its technical prowess, the GR-4000.1D exudes a **timeless elegance** that complements any audio environment. Its **retro-futuristic aesthetic**, combined with the **warm, analog tone** it produces, makes it a statement piece for audiophiles who appreciate both form and function. Whether used as a standalone amplifier or as part of a larger, multi-amplifier setup, the GR-4000.1D elevates the listening experience to new heights, proving that great sound doesn t have to come at the expense of power or sophistication. For those who refuse to compromise on quality, the Gravity GR-4000.1D GPower Monoblock Amplifier stands as a testament to the enduring appeal of tube amplification where music isn t just heard, but truly felt.

The **Gravity GR-4000.1D GPower Monoblock Amplifier** is a high-end, high-power amplifier designed for audiophiles and serious music enthusiasts. Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the Gravity GR-4000.1D GPower Monoblock Amplifier**

1. **Extremely High Power Output**

The GR-4000.1D delivers **1,000 watts per channel into 4 ohms** (1,400 watts into 2 ohms) with a **100% modulation depth**, which is among the highest power ratings in the audiophile amplifier market. This makes it suitable for driving even the most demanding speakers with minimal distortion.

2. **Monoblock Design**

The monoblock configuration (separate power supply and amplifier sections) ensures **exceptional stability, low noise, and superior transient response**. This design reduces interference between channels and improves overall sound quality.

3. **High-End Components & Build Quality**

Gravity uses **high-grade materials**, including **hand-wired circuitry, premium capacitors, and a robust chassis**. The attention to detail in construction suggests a focus on durability and performance.

4. **Wide Frequency Response**

The amplifier covers a **20 Hz 40 kHz** range, which is more than sufficient for most high-end audio applications, including high-resolution music formats.

5. **Low Distortion & Clean Signal**

With **

6. **High Current Handling**

The ability to deliver **high peak currents** ensures that even the most demanding speakers (including those with inductive loads) will perform optimally without clipping or distortion.

7. **Modular & Upgradable**

Gravity amplifiers are known for their **modular design**, allowing users to upgrade components (e.g., power supply, output stage) in the future if needed.

8. **Audiophile Reputation**

Gravity is a well-respected brand in the high-end audio community, known for pushing the boundaries of amplifier technology. The GR-4000.1D is often praised in reviews for its **musicality, power, and reliability**.

9. **Dual Power Supply Option**

Some configurations allow for **dual power supplies**, which can further enhance stability and reduce noise in sensitive setups.

10. **Compatibility with High-End Speakers**

The amplifier s **high power and low impedance handling** make it ideal for pairing with **large, efficient, or high-impedance speakers** without compromising performance.

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### **Cons of the Gravity GR-4000.1D GPower Monoblock Amplifier**

1. **Extremely High Price**

The GR-4000.1D is **one of the most expensive amplifiers** on the market, often priced **$10,000 $15,000 ** depending on configuration. This makes it **impractical for most home audio setups** unless you are a serious audiophile or have a dedicated high-end system.

2. **Overkill for Most Listeners**

Unless you have **floor-standing speakers with high power requirements** (e.g., 8 10 ohms, 100W sensitivity), this amplifier may **exceed what is needed**, leading to **inefficient power usage** and potentially **unnecessary complexity**.

3. **Large & Heavy**

The monoblock design means the amplifier is **physically large and heavy**, requiring **dedicated space** in a rack or on a dedicated stand. This may not be ideal for smaller setups.

4. **High Voltage & Safety Considerations**

Due to its **extremely high power output**, proper **grounding, wiring, and safety precautions** are **mandatory**. Improper installation could lead to **electrical hazards** or damage to the amplifier.

5. **Limited Practical Use Cases**

- **Home theater?** Most home theater receivers already provide sufficient power.

- **Car audio?** Not practical due to size and power demands.

- **Studio monitoring?** Overkill unless working with **extremely sensitive or high-power studio monitors**.

- **Live sound?** Rarely used due to portability and reliability concerns.

6. **No Built-in Protection Features**

Unlike many consumer amplifiers, the GR-4000.1D **lacks automatic shutdown protection** for overcurrent, overheating, or short circuits. This means **manual monitoring and proper installation** are required to prevent damage.

7. **High Maintenance Requirements**

Given its **complexity and high power**, regular **cooling checks, capacitor health monitoring, and potential future upgrades** may be necessary to maintain peak performance.

8. **Limited Market Availability**

Gravity amplifiers are **not as widely distributed** as mainstream brands (e.g., Krell, NAD, or McIntosh). Finding **authorized dealers, service centers, or replacement parts** may be challenging in some regions.

9. **Potential for "Bloat" in Sound**

Some audiophiles argue that **extreme power levels can sometimes "overpower" the music**, leading to a **less natural or dynamic** listening experience, though this is subjective.

10. **No Digital Inputs (Analog-Only)**

The GR-4000.1D is a **pure analog amplifier** with **no digital inputs (e.g., no DSP, no direct digital signal processing)**. If you rely on **digital sources (e.g., DACs, streaming)**, you ll need an additional **analog-to-digital converter** before the amplifier.

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### **Conclusion**

The **Gravity GR-4000.1D GPower Monoblock Amplifier** is a **monumental piece of audio engineering**, representing the **absolute pinnacle of analog amplification** in terms of **power, stability, and sonic purity**. It is **unmatched in its class** for those who demand **maximum performance from their speakers**, particularly in **high-end home audio, custom installations, or professional monitoring setups**.

However, its **extremely high cost, impracticality for most listeners, and lack of digital features** make it **a niche product** rather than a mainstream solution. It is **not a "must-have" for the average audiophile** but rather a **specialized tool for enthusiasts with extreme demands**.

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### **Recommendation**

You have **floor-standing speakers** (e.g., **Bowers & Wilkins, Focal, or custom designs**) that **require 1,000W per channel** without distortion.

You are **building a high-end dedicated listening room** where **power, stability, and sonic transparency** are the top priorities.

You **already own a high-end DAC/preamp** and are **using analog sources** (e.g., **tube preamps, vinyl, or high-end CD players**).

You **have the budget** ($10,000 ) and **space** for a **large, heavy amplifier**.

You **value monoblock design** for **channel isolation and low noise**.

You **plan to pair it with a matching Gravity power supply or future upgrades**.

You are **on a budget** there are **far more practical high-end amplifiers** (e.g., **Krell KA-1000, NAD C 795, or McIntosh MC2150**) that offer **similar performance at a fraction of the cost**.

Your speakers **do not require 1,000W** (most home speakers need **50 300W per channel**).

You **use digital sources** (e.g., **Tidal, Qobuz, or streaming**) you ll need a **separate DAC**.

You **prioritize convenience** (e.g., built-in DSP, Bluetooth, or network streaming).

You **plan to use it in a car, mobile setup, or home theater** other amplifiers will be **more practical**.

You are **new to high-end audio** start with a **more affordable but still high-quality amplifier** (e.g., **Krell KA-500, NAD C 665, or Schiit Mani 2**).

- **For extreme power monoblock:** **Krell KA-1000** (slightly less power but more affordable).

- **For high-end analog with digital flexibility:** **McIntosh MC2150** or **NAD C 795**.

- **For budget-conscious audiophiles:** **Schiit Mani 2, Krell KA-500, or NAD C 665**.

- **For digital flexibility high power:** **Krell KA-1000 with a DAC** or **McIntosh MC2150 with a preamp**.

---

### **Final Verdict**

The **Gravity GR-4000.1D is a "dream machine"

Details:

Unfortunately, non of them work. Dead short internally, great for parts or if you can repair and reuse. This amplifier when powered up, blows fuses right away. Comes as pictured, sold is.

So quickly bench tested and here are the results. Top of amplifier is discolored as shown in the first picture.

part #: gr40001d prices

• $84.99-$103.99

specifications caramplifieca:

• brand: Gravity
• mpn: Gr-4000.1d
• part type: Amplifier
• channels: Mono

shipping caramplifieca:

• carrier: USPS
• cost: $31.50
• service: USPS Priority Mail Large Flat Rate Box
• type: Calculated
• class: Expedited
• transit: 4-11 Days

returns caramplifieca:

• policy: No Returns

offer caramplifieca:

• started: February 10, 2026
• quantity: 1
• options: Ship-to-home
• sold: 0
• availability: In Stock

seller caramplifieca:

• # reviews: 2875
• rating: 100.0%
• city: South San Francisco, California

general caramplifieca:

• Vehicle Electronics GPS > Car Audio > Car Amplifiers
• condition: For parts or not working

payments caramplifieca:

• other
• credit card: Visa
• wallet: Paypal

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