Ohma vs. Vintage Tube Microphones: A Detailed Comparison

At Ohma World, we design microphones inspired by the iconic vintage mics of the 1950s, 60s, and 70s. But we don’t stop at inspiration—we strive to create a microphone that holds its own alongside the legendary tools that shaped the music industry. The Ohma condenser microphone stands proudly in comparison to these aspirational vintage models, some of which command prices exceeding $30,000 today.

The Ohma Condenser isn’t a clone of any vintage mic—just as none of these vintage mics is a clone of another. Our approach was to analyze what made each of our favorite microphones special, distill their best qualities, and combine them into a microphone that offers a fresh option for today’s artists.

A microphone is not just a capsule—it’s an entire system where every component plays a critical role in shaping the sound. The grille design and shape affect how sound waves reach the capsule, influencing factors like high-frequency detail and off-axis response. The electronic circuit, including components like transformers or FETs, determines how the signal is amplified and colored, contributing to the microphone’s tonal character, noise floor, and dynamic range.

However, in a condenser microphone, the capsule is the starting point and the heart of the microphone. It captures the initial vibrations of the sound wave, converting them into an electrical signal. The capsule’s design—whether it’s edge-terminated or center-terminated, single-backplate or dual-backplate—dictates much of the microphone’s fundamental sonic profile, including its frequency response, sensitivity, and transient handling.

Each piece of the system interacts with the others, meaning a change in any one component can dramatically alter the overall sound. A truly great microphone balances all these elements, ensuring they work harmoniously to deliver the desired tone and performance.

Unlike the tube-based amplifiers in these vintage models, the Ohma employs a FET (Field Effect Transistor) design, making it the only solid-state mic in this test. We adore vintage tube mics, but FET offers a modern flavor that’s equally compelling.

To showcase the Ohma Condenser’s capabilities, we compared it to five legendary Vintage microphones that were released in the 1950s - 1970s: the Telefunken 250, Neumann U67, Neumann/Telefunken U47, AKG C24, and Sony C-37A.

1. Frequency Response Analysis: Using a dual-concentric speaker and REW software, we measured each microphone’s frequency response to highlight their tonal characteristics. However, frequency response only tells part of the story—sound is ultimately subjective.

2. Optimal Placement: Every mic in this comparison has unique proximity effects and polar patterns, so we positioned each microphone to capture the optimal sound for the voice of Ohma co-founder and president, Char Gibbs, performing a cover of Cake’s Four Letter Word.

3. Procedures: We aligned all of the microphones at 1 kHz to provide a clear baseline for comparison. By normalizing the output at this frequency, we were able to minimize discrepancies in sensitivity and output levels across the various models. This method ensures that the differences you see in the frequency response charts—and more importantly, hear in the recordings—are not the result of mismatched levels but true reflections of each microphone’s design and tuning. Aligning at 1 kHz also highlights how each microphone responds to different frequency ranges, making the contrasts between their tonal profiles more apparent and informative. This approach was critical in revealing the subtleties of each microphone’s sound.

4. Pop Filter: We chose a Steadman pop filter to help reduce plosives and wind noise during our testing. Known for its exceptional transparency, the Steadman allows the microphone’s natural characteristics to shine through without adding coloration. In fact, when we conducted frequency response tests, there was no measurable audible or technical difference between recordings made with and without the Steadman. Stay tuned for an upcoming article where we’ll dive deeper into pop filter comparisons and share insights from our extensive testing.

5. Interface and Preamp: For our recordings, we used an Apollo x8p interface, relying solely on its preamps with zero plugins or additional processing. The Apollo x8p was chosen because it’s a widely popular interface known for its transparent sound, making it an excellent frame of reference for listeners. We kept the recordings completely clean—no EQ, no noise reduction, no reverb—so you can hear each microphone exactly as it sounds without any alterations. This approach ensures an honest and direct comparison across all the microphones tested.

Our goal was not to crown a “winner,” but to demonstrate how the Ohma stands alongside these classics as well as to show where some of the characteristics of the Ohma Condenser came from.

Market Price: $30,000

The younger sibling of the Telefunken 251, the 250 shares its edge-terminated capsule and electronics, minus the figure-8 polar pattern. It has a rich low-end, smooth midrange, and a noticeable peak at 6.6 kHz. Manufactured by AKG and distributed by Telefunken, this particular unit is an early version (sub-serial number 500), making it a rare and treasured example of its kind.

The 250 is a mic we know intimately at Ohma—it was one of our earliest inspirations when we began designing microphones. In fact, the very first microphone we ever built as teenagers was a 251 clone. Through years of experimentation and study, we’ve come to deeply appreciate the qualities that make this microphone special, from its rich low end and smooth midrange to its subtle yet musical top-end presence.

That said, vintage microphones like the 250 come with their quirks. After decades of use, it’s rare to find units that sound consistent from one to the next, even within the same model line. Fortunately, this particular 250 is one of the exceptional ones, with a frequency response that’s mostly flat except for a characteristic peak around 6.6 kHz. For the Ohma condenser, we intentionally tuned a similar peak, albeit slightly higher at 8.5 kHz, to retain clarity without straying into harshness. Similarly, the 250’s subtle low-end bump was another trait we loved and worked to replicate in our own way.

The Ohma Condenser also employs an important technique used in the original 250: gluing the capsule’s membrane. While modern manufacturing shortcuts often forgo this step, we’ve found that gluing allows for better tuning and ensures long-term consistency. This meticulous process, borrowed from vintage craftsmanship, helps stabilize the membrane over time, reducing variations and ensuring the Ohma condenser delivers reliable performance year after year.

Market Price: $15,000

The Neumann U67 is a classic microphone from the late 1960s and early 70s, renowned for its unique tonal character. The model we tested is one of the better-preserved examples, showing remarkable consistency compared to other U67s we’ve encountered.

One of the defining traits of the U67 is its midrange bump between 3 to 6 kHz, a feature we’ve nicknamed "The Claw" at Ohma due to its shape on a frequency response graph. This bump contributes to the U67’s vibe, giving it a rich, present sound that can be magical with the right singer. However, this same characteristic can sometimes make the mic sound harsh on certain instruments or voices.

When designing the Ohma condenser, we kept a close eye on this feature. While "The Claw" is a standout feature of the U67, we wanted to create a microphone that avoided such pronounced peaks, opting for a smoother, more balanced response that’s versatile across a wide range of sources. By doing so, we’ve crafted a mic that retains the U67’s charm but addresses some of its potential harshness- especially for instruments like drums and guitars.

In designing the Ohma condenser, we wanted to capture the U47’s sense of balance and warmth while eliminating some of the inconsistencies and quirks of its era. For example, the aging PVC membrane of the M7 capsule is known to degrade over time, altering the frequency response and tone of the mic. By using modern materials and precision engineering, the Ohma delivers the same kind of warmth and balance but with the consistency and reliability that today’s recording environments demand.

Another notable difference is in the capsule design. Both the U47 and the Ohma use single-backplate designs, which are known for their smooth top end when tuned correctly.. However, the Ohma employs an edge-terminated capsule (like the 251 and AKG C12), while the U47 uses a center-terminated capsule.

This unit has a beautifully balanced frequency response with a midrange boost between 3 and 6 kHz—same as the “Claw” observed in the U67 but even more pronounced. This midrange bump is part of the signature Neumann sound, adding a sense of presence and energy to the mic’s otherwise warm and natural tone.

The U47 remains a masterpiece of its time. It’s not about replacing the U47—it’s about building on its legacy with a fresh, modern perspective.

Market Price: $25,000

The AKG C24 is a fascinating stereo microphone that uses the same capsule design as the Telefunken 250 and 251. However, its stereo configuration introduces unique variables: each of the C24’s capsules can sound notably different from the other. When we tested it, we listened to both capsules individually, and as expected, their frequency response curves and tonal characteristics varied. This variability highlights one of the quirks of vintage microphones—while both capsules sound great, they don’t necessarily sound identical.

Capsules are critical to the sound of any microphone, and with the C24, this truth becomes even more evident. If you change the capsule, you drastically alter the mic’s sonic profile. This variability is part of the charm of vintage microphones, but it also underscores the importance of rigorous quality control in modern manufacturing. At Ohma, we’ve invested heavily in precision testing and QC to ensure that every capsule we produce is not just good but consistently so—something that’s harder to achieve with vintage designs.

When comparing the C24 to the Ohma condenser, the differences in tuning are immediately apparent. The C24’s frequency response is similar to the Telefunken 251, with a pronounced resonance peak in the high frequencies. However, the C24’s peak occurs lower, around 5.5 kHz, compared to the Ohma’s intentionally tuned peak at 8.5 kHz. This lower peak, combined with the chambered dual-backplate design of the C24’s capsule, creates a resonance that feels a bit too forward in the midrange for our taste. Additionally, the C24 exhibits a substantial dip—about 9 dB—from 6.5 kHz to 13 kHz, making its high-frequency response uneven: bright in some areas, dark in others.

What stands out positively about the C24 is its low-end response, which is reminiscent of the capsule used in the Telefunken 250. This characteristic is a hallmark of a well-designed edge-terminated capsule and is something we’ve always admired in the C24. While the Ohma condenser takes a different approach to tuning, we share the C24’s appreciation for smooth, balanced low-end performance—just with a more even and versatile high-frequency profile.

The AKG C24 is a testament to the innovative engineering of its time, and its stereo capabilities remain impressive. However, its quirks and variability also remind us why modern microphones like the Ohma strive to improve upon these classic designs—delivering the warmth and richness we love in vintage microphones while offering consistency and reliability for today’s recording needs.

Market Price: $15,000

The Sony C-37A is a truly unique microphone, both in design and sound. One of its standout features is the mechanical switch on the back that changes the polar pattern which was commonly found in ribbon microphones in the 1950s—a rarity among condenser microphones. However, what really sets the C-37A apart is its tonal character, which manages to be both dark and airy at the same time.

In terms of frequency response, the C-37A exhibits a significant dip between 6.5 kHz and 13 kHz, similar to what is seen in the AKG C12, giving it a darker tonal foundation. Yet, it also features a massive peak around 15.5 kHz, resulting in a bright and “airy” quality that no other microphone in this test achieves quite the same way. This juxtaposition creates a sound profile that is rich and warm while maintaining an almost ethereal top-end presence.

The C-37A uses an edge-terminated, single-backplate capsule like the Ohma condenser, but its single membrane design, structural, and tuning choices result in a distinctly different sound. The pronounced peak at 15.5 kHz is part of its charm, though it can occasionally feel overly sharp, depending on the source.

The C-37A’s ability to balance warmth and airiness makes it a fascinating microphone. While it may not be ideal for every recording scenario, its quirks give it a character and charm that has made it a beloved classic in certain circles.

The Ohma condenser microphone isn’t just a nod to vintage microphones—it’s a modern interpretation that captures the soul of these classics while offering its own distinctive voice. From its carefully tuned capsule to its FET amplifier, the Ohma condenser is designed to be a versatile, high-performing tool for today’s recording environments.

If you’re curious to hear the difference for yourself, download the unprocessed stems and listen to these microphones in your DAW of choice.

We hope this comparison illustrates the Ohma Condenser’s exceptional quality and unique character. Just like the vintage mics that inspired it, the Ohma condenser isn’t just another microphone—it’s a piece of history in the making.

Special thanks to our good friend Michael for providing the vintage mics for this test!