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Quadratic Audio MC-1 Moving Coil Gain Stage
Phono Step-Up Transformer (SUT) with 28 and 22 dB Gain Options
Quadratic Audio MC-1 Moving CoilPhono Step-Up Transformer
The MC-1 is a passive gain stage designed to elevate the low output of moving coil cartridges to levels compatible with standard phono preamps. Commonly referred to as a step-up transformer (SUT), the MC-1 goes further—staging a complete signal path built around custom-built CineMag transformers, shielding-aware layout, and perceptual discipline.
This isn’t about sterile amplification. It’s about preserving nuance, rejecting noise, and honoring the sonic character that makes vinyl playback so compelling. The MC-1 doesn’t strip away color—it protects it.
Design Philosophy
The MC-1 is the brainchild of Jam Somasundaram, whose decades of analog design experience include work on respected gear from Pass Labs, Ayre Acoustics, and Cary Audio. Known for his obsessive attention to layout, grounding, and shielding, Jam approached the MC-1 as a complete gain stage—not just a box with transformers. From the choice of custom-built CineMag transformers to the internal architecture and connector integrity, every detail reflects his commitment to preserving the delicate output of moving coil cartridges with clarity and control.
Gain Configuration
Gain is user-selectable—either +28 dB or +22 dB—via internal jumpers. This allows precise matching to a wide range of MC cartridges, whether you're working with ultra-low output designs or more conventional moving coil models. If you're unsure which setting suits your setup, we’re happy to help you make that determination.
Build Quality & Materials
The MC-1 is built like it means something. The front panel is machined from solid ½" aluminum, bead-blasted to a matte finish that feels both tactile and refined. The steel chassis is finished in black, offering contrast and durability. This isn’t just a protective enclosure—it’s a visual statement. The MC-1 is substantial, decorative, and unmistakably serious.
Inside, a glass epoxy circuit board houses the gain jumpers, flanked by custom-built CineMag transformers enclosed in mu-metal shielding cans. Signal routing is handled by shielded coaxial cables terminated with TNC connectors—chosen for their mechanical integrity and superior shielding. Neutrik RCA panel connectors complete the signal path, ensuring robust and noise-resistant connections.
Noise Rejection & Shielding Strategy
Moving coil cartridges produce extremely low output, making them vulnerable to electromagnetic interference. The MC-1 counters this with a multi-layered shielding strategy:
- Mu-metal transformer cans provide over 30 dB of isolation
- Faraday shielding adds a second layer of defense against EM ingress
- Superior common-mode rejection minimizes hum and environmental noise
This isn’t just shielding—it’s signal preservation, staged with purpose.
What Listeners Are Saying
"Should you be in this exact situation, where you have an excellent MM phonostage you love, but just need a bit more gain, the MC-1 is the perfect solution"
"...the Quadratic MC-1 is in a league of its own"
TONEAudio Magazine
"I've only had the Quadratic MC-1 for a week, but in short I've really enjoyed it and am glad I bought it. It's looking like it'll be getting a lot of play time here!"
AudiogoN Forum
"...the Quadratic was virtually immune to hum"
"Does it go so far as to produce a totally immersive listening experience? Absolutely, it does. This is one of the few times when a third-party product with a variety of settings can actually handle and do justice to a wide variety of different cartridges and handle each with ease, poise and dexterity"
MUSIC GEAR
"I was very surprised when I tested Quadratic Audio’s MC-1 transformer this time. In addition to providing a powerful gain, it is also quite good at noise control, making the music fuller and denser. Although Quadratic Audio is currently a relatively new brand, if you consider the improvement in sound quality performance, it is really a good deal..."
AUDIOTECHNIQUE
Loaner Program (Let’s Talk About Trust)
We know sonic preferences are personal, and we want you to feel confident exploring the MC-1 in your own system. That said, this is a precision-built $1800 gain stage—not something we can casually send out and hope for the best.
Here’s how we handle it: If you’re serious about auditioning the MC-1, reach out. We’ll talk through your setup, your expectations, and whether a short-term evaluation makes sense. If we agree to a loan, we’ll document the terms clearly—including return condition, time frame, and a refundable deposit. No fine print, no surprises. Just mutual respect.
Made in the USA, With Purpose
The MC-1 is designed and manufactured in the USA, in partnership with CineMag—whose custom-built transformers have earned trust across mastering studios and archival labs for decades. In a market flooded with knock-offs and badge-engineered imports, Quadratic stands apart by building gear that reflects American engineering values: clarity, durability, and signal-first intent.
Covered by a 3-year limited warranty, the MC-1 isn’t just a product—it’s a gain stage built for listeners who care about what’s beneath the surface.
Here is another perspective.
The high-quality Neutrik RCA jacks and ground terminal can be seen in this photo of the back panel.
CineMag inside!
Here is a better look inside. Jumpers for gain setting can be seen in the foreground, and the custom CineMag transformers are also prominent. Coaxial cables with gold-plated threaded connectors can also be seen.
Here is a look at the bottom of the Step-Up transformer.
Quadratic Audio protects the MC-1 with a nice drawstring fabric bag and molded foam padding. The package includes extra jumpers for gain selection, a printed manual, and the SUT device itself.
This photo shows the sturdy product box (we will also double-box for safe shipment).
Here is the manual, in PDF format.
Why Cable Solutions?
- We stock this item locally, ready for immediate shipment, and no one works harder than we do to get your order shipped out to you fast! On business days, orders that are funded by noon will ship the same day. Orders funded on weekends or holidays will ship the next business day.
- Cable Solutions is an Authorized Quadratic Audio Distributor, so our customers are ensured full warranty protection and technical support. (Quadratic Audio does not provide warranty or technical support for products purchased from unauthorized resellers!)
- Customer service is our first priority. We do our best to help you find the best solutions for your particular application. We're enthusiasts too, so we know what it's like to wait for parts that are needed for new gear. We also know how important it is to be able to get a response when you need help, so you'll often find us working long hours in an effort to get you the answers that you need.
- If you have had enough of sellers who have never actually seen the products that they sell, let alone have any idea how to support the customers who purchase them, or worse yet, companies that do not even publish a phone number or a functional email address, we think you will be absolutely delighted that you found our company. We know how important it is to be able to get help when you need it. That's why we have people, right here in Texas, ready to respond to your email or answer your phone call. If English is your language of choice, you will have the simple pleasure of communicating with people whose first language is English. Granted, if you call on the phone, you may detect more than a trace of a Texas accent, but that is to be expected when dealing with a family-owned business run by native Texans. We sincerely hope that you will find our heritage of courtesy, honesty, and an ethical way of doing business to be a refreshing experience.
Design excellence, high quality materials, meticulous workmanship, and superior service...put it all together and you get a superior product. Don't get stuck with bad advice, poor service, slow shipment or an inferior product. If you want the best, here it is.