Innertube U87 AI Tube Mod brings legendary tube warmth and vintage depth to your U87 AI mic. Discover how this mod upgrades tone, vibe, and value.
The Neumann U87 AI is a legend in the world of stufdio microphones. Revered for its pristine clarity, balanced frequency response, and versatility, the U87 AI has earned its place in countless professional studios.
However, while it excels in many areas, some audio engineers and producers feel that the modern U87 AI lacks the character and warmth found in vintage tube microphones.
In this article, we’ll dive deep into what the Innertube U87 AI tube mod is, how it works, what it sounds like compared to the stock U87 AI, and whether it’s the right choice for your studio. Let’s explore how this mod is reviving the soul of vintage tone in a modern studio classic.
What Is the Innertube U87 AI Tube Mod?
A Brief History of the U87 AI
Since its debut in 1967, the Neumann U87 has been a studio staple. The Innertube U87 AI Tube Mod, its modern counterpart introduced in the 1980s, features improved electronics and higher output, but it retains the same physical design and capsule. While the U87 AI is incredibly reliable and sonically consistent, many engineers find it a bit too clinical compared to its older U67 and U47 ancestors.
The Birth of Innertube Audio
Innertube Audio, founded by respected engineer John Peluso, specializes in vintage-inspired audio modifications. The Innertube U87 AI tube mod is one of the company’s most notable offerings. It replaces the solid-state circuitry of the U87 AI with an entirely new, high-voltage vacuum tube-based circuit.
Purpose of the Mod
The mod’s goal is to recreate the lush, harmonically rich tone of vintage tube microphones while preserving the Innertube U87 AI Tube Mod well-loved capsule and design. By inserting a custom-built tube circuit, Innertube aims to inject the U87 AI with the warmth, saturation, and depth that made vintage tube mics legendary.
Technical Breakdown of the Mod
Circuit Design Differences
At its core, the Innertube mod replaces the FET (Field Effect Transistor) design of the Innertube U87 AI Tube Mod with a class A, all-tube circuit. This redesign requires significant internal changes, including high-voltage components and shielding adjustments to reduce noise.
The modified circuit uses point-to-point wiring, high-quality capacitors, and precision resistors to ensure minimal signal degradation. This analog purity is what gives the modded Innertube U87 AI Tube Mod its signature vintage tone.
Vacuum Tube Type Used
Innertube typically uses a subminiature 6418 or 5840 vacuum tube, chosen for its low noise and desirable harmonic profile. These tubes are known for their warm midrange, smooth high-end, and rich harmonic distortion—perfect for studio applications.
Internal PSU or External Power?
The Innertube U87 AI tube mod requires an external power supply, as the tube circuit needs more voltage than the original phantom-powered FET circuit can provide. The PSU is custom-built, quiet, and optimized for studio use. It connects via a 7-pin XLR cable to the microphone.
Components and Build Quality
Every component used in the mod is hand-selected. The build quality is boutique-grade—what you’d expect from a high-end, analog mod. The attention to detail ensures not only superior sound but also long-term reliability. Users consistently praise Innertube for its craftsmanship.
Sound Comparison – Stock vs. Modded U87 AI
Audio Characteristics
The Innertube U87 AI Tube Mod is neutral, clean, and precise—ideal for modern pop vocals, voiceover, and broadcast. But in comparison, the Innertube-modified U87 AI delivers:
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Increased warmth in the low and midrange frequencies
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Smooth, velvety highs with a touch of tube-driven saturation
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More pronounced presence, especially on vocals and acoustic instruments
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Harmonic complexity that adds depth and musicality
Applications in the Studio
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Vocals: The modded mic flatters all vocal types, adding analog-style roundness and intimacy.
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Acoustic Instruments: Guitars, strings, and pianos benefit from the additional harmonic content and softened transients.
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Overheads: The tube warmth can smooth cymbals and bring body to drum kits.
What Producers & Engineers Say
Respected producers who’ve used the Innertube U87 AI tube mod often describe it as “a U87 with a soul.” Some compare it favorably to vintage U67s, stating that it gets “surprisingly close” in tone, especially on vocals and acoustic material.
Pros and Cons of the Mod
Advantages
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Vintage Tone: Adds tube warmth, richness, and a more musical coloration.
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Improved Depth: Enhanced harmonic content and three-dimensional imaging.
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Unique Sonic Identity: Offers a distinct voice compared to stock U87s.
Disadvantages
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Cost: At around $1,000–$1,500 for the mod, it’s a significant investment.
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Permanent Alteration: The mod is not easily reversible; it changes the mic’s internal electronics.
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Serviceability: Requires specialized knowledge to maintain and repair.
Who Should Consider This Mod?
Best Suited For:
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Analog enthusiasts: Those chasing vintage tones in a modern workflow.
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Professional studios: Ideal for top-tier vocal chains and boutique setups.
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Producers working in jazz, soul, indie rock, or classical: Where tube characteristics shine.
Not Recommended For:
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Broadcast or podcasting: The extra coloration might not suit voiceover clarity needs.
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Engineers requiring neutrality: If you want a clean, accurate mic, the stock U87 AI is better.
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Budget-conscious users: Between the mic and the mod, this is a premium option.
Price, Availability & Alternatives
Cost of the Mod
The Innertube U87 AI tube mod typically costs between $1,000 and $1,500, not including shipping. This price includes the modification, tube circuit installation, and external power supply.
Where to Get It Done
The mod is available directly through Innertube Audio, though wait times may vary depending on demand. It’s advised to contact them before sending in your microphone.
Alternatives to Consider
If you’re interested in tube-style sound but want different options, here are some notable alternatives:
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Blackspade UM17R: A modern tube mic with vintage flair.
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Advanced Audio CM87se Mod: Offers a vintage U87 tone at a lower cost.
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Flea 47 or 49: Premium vintage recreations based on classic Neumann designs.
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Peluso 2247 SE: Inspired by the U47 with modern reliability.
Each of these options has a different sonic fingerprint but caters to the same tonal goals: tube warmth, analog charm, and a distinctive studio sound.
Conclusion
The Innertube U87 AI tube mod is more than just an upgrade—it’s a reinvention of a modern classic. By replacing the sterile FET circuitry with a lush, high-voltage tube design, this mod breathes new life into the U87 AI, delivering the warmth, depth, and musical saturation that vintage gear lovers crave.
Whether you’re a studio owner looking to add another sonic flavor to your locker or a producer chasing analog richness, this mod is worth serious consideration. Just be prepared for the commitment—this isn’t a plug-and-play tweak but a bold step toward true vintage-style tone.
For those seeking a mic with personality, vibe, and that elusive analog glow, the Innertube U87 AI tube mod might just be your ultimate studio companion.
FAQs
What tube is used in the Innertube U87 AI mod?
The mod typically uses a 6418 or 5840 subminiature tube, chosen for its warmth, low noise, and musical harmonic response.
Does the mod affect the resale value of my U87 AI?
Yes. While some buyers seek out modded mics, others prefer stock. The resale value depends on demand and the quality of the mod.
Can I revert back to stock after the mod?
Not easily. The mod involves permanent changes to the internal circuit. Reverting would require major rework and may not restore the mic to exact factory spec.
Is the mod compatible with the original U87 (non-AI)?
No. The mod is specifically designed for the U87 AI version and isn’t compatible with older U87 circuits or capsules.
Will the mic still use phantom power after the mod?
No. The mod requires an external power supply unit (PSU) and will not function with standard 48V phantom power.