RM-7: The Active DIY Ribbon Mic Kit with Ultra Low Noise

Now the ribbon mics will sound awesome even with a budget audio interface!

Bumblebee Pro RM-7 Active DIY Ribbon Mic is a tool that will make your recordings sound smooth and silky. The built-in preamp keeps the noise floor virtually the same as with passive ribbons, while producing a condenser-like output level. As always, the kit comes with a fully assembled and tuned motor. You only need a soldering iron and basic soldering skills. All the extreme “jewelry” work is already done by an experienced professional technician.

Bumblebee Pro RM-7 Active DIY Ribbon Mic Kit - All The Parts
Bumblebee Pro RM-7 DIY Ribbon Mic Kit Fiber Laser Logo
Bumblebee Pro RM-7 Active DIY Ribbon Mic Kit Preamp PCB
RM-7 DIY Active Ribbon Mic Kit - Test The Microphone System Outside The Body
RTX-28 DIY Ribbon Mic Transformer

The Ribbon Mic with a Soul

When I started making my first ribbon motor from a piece of plastic in 2010, I couldn’t imagine that it would become my full time occupation. But, hey, now we are a team of three dedicated people creating DIY Ribbon Mic Kits for recording enthusiasts and professionals from all around the world.

Not a single part of a microphone is still the same as it was in 2010. We have been continuously upgrading each element of our DIY ribbon mics. However, one thing remains unchanged – I make sure that every part is crafted with such care as if I would build a microphone for my own studio.

Now, please welcome the RM-7 DIY Ribbon Mic!

The Motor with The Unique Design

Every RM-7 DIY Ribbon Mic Kit comes with the RE-423 Ribbon Mic Motor. The motor is the heart of a ribbon microphone and the essence of the sound. That’s the part where the most of the magic happens.

The ribbon produces a smooth sound, free from mid and high frequency resonances. The absence of such resonances means that the most sensitive range of a human ear is free from sonic artifacts. This is the key secret of the natural and authentic ribbon sounds that we all love.

Why does the RE-423 Motor Sound So Well?

Bumblebee Pro RE-423 DIY Ribbon Mic Motor
Bb-A20 DIY Ribbon Mic Activator Kit

Ultra-Low Noise Internal Preamp

Did you ever want to start recording quiet instruments with ribbon microphones, but the need of a very expensive high-gain and low-noise preamp would stop you? I’ve got the great news – now you can do it!

Each RM-7 ribbon mic kit comes with a Bb-A20 Ribbon Mic Activator Kit. The Bb-A20 preamp adds the clean, noiseless and perfectly transparent gain. It is based on high-end ultra-low noise 2SA970BL transistors. Therefor, The RM-7 DIY Ribbon Mics record the most delicate sound sources perfectly, even with a regular audio interface or preamp.

DIY Ribbon Mic Activator Kit Assembly Manual - Ceramic Capacitors
DIY Ribbon Mic Activator Kit Assembly Manual - Ceramic Capacitors
DIY Ribbon Mic Activator Kit Assembly Manual - Diodes
DIY Ribbon Mic Activator Kit Assembly Manual - Resistors

Fancy Polishing and Engraving

The visual aesthetic is as important as a sound

Not exactly audio related, but still worth pointing out. A new local metal works contractor re-developed the mic body machining process for the RM-7 DIY Ribbon Mic Kit production.

With the full CNC process the part repeatability and accuracy stepped up to a next quality level. We’ve re-designed and re-standardized our signature brushed steel finish for the fancier textured look. The Bumblebee logo is slightly updated, but the fiber laser engraving still makes it perfectly durable.

As a result, I proudly dare to consider that the visual appearance of the RM-7 DIY Ribbon Mic can stand next to any branded product.

Bumblebee Pro RM-7 DIY Ribbon Mic Kit Fiber Laser Logo
RM-7 DIY Active Ribbon Mic Kit - Prepare To Test The Activator
RTX-28 DIY Ribbon Mic Transformer

Our Own Toroidal Transformer

While the Ribbon Mic Motor produces the sound, the transformer amplifies this ultra-low signal up to a working level. The main goal of the transformer design is to preserve the natural beauty of the initial sound.

The RTX-28 transformer is our own elaborate design. The toroidal nanocrystallic iron core produces a very low distortion. The thick winding wire together with short turn length produce the lowest possible resistance. The epoxy molding makes the transformer perfectly reliable. All together, the synergy of these features creates the transformer that preserves the sound of the instruments in greatest detail.

We manually test each RTX-28 ribbon mic transformer and match the pairs according to the inductance of the primary windings.

Check Out The Demo Recordings

We've recorded these compositions with just one Blumlein pair

The demos below show off the RM-7 DIY Ribbon Mics in different applications and genres. Most of the sample composition were recorded with RM-7 Active DIY Ribbon Mics with 1.2 micron ribbons. We recommend RM-7 Ribbon Microphones for acoustic recordings, so we’ve concentrated on acoustic music demos.

Acoustic mantra music that features male vocals, acoustic guitar, flute and percussion. The recording has wide dynamics – from a very quite beginning to an intense culmination.

The recording of a harpsichord made by a customer from Japan. Kanji Daito plays J.S.Bach French Suite No.4 in E flat major. The RM-7 mics with 1.8u ribbons were used.

A very unusual use for ribbon mics – a remote recording with Zoom H4n. The wind protection didn’t block all the blasts, but we still decided to keep this version, as it sounds cool.

The acoustic blues piece featuring rough male vocals, acoustic guitar and an upright bass. The recording shows great guitar playing and a very clean separation of instruments.

Easy to Follow Assembly Manual

If you have ever soldered a cable - you can assemble this kit!

Every DIYer with basic soldering skills and a fine-tipped soldering iron can assemble the RM-7 Ribbon Mic Kit easily. The included Bb-A20 Ribbon Mic Activator preamp circuit is self-balancing, the microphone will work perfectly right after all the parts are soldered together.

Check out the illustrated step-by-step assembly manual for the RM-7 DIY Ribbon Mic Kit. The manual is super-easy to follow and makes each step perfectly clear with the photos and descriptions of each process.

Also, check out the Bb-A20 Mic Activator assembly manual. In case if you are not perfectly sure about your fine-soldering skills, you can order the preamp PCB fully assembled and tested. You can find this option on the RM-7 order page.

RM-7 Active DIY Ribbon Mic Kit
RM-7 DIY Active Ribbon Mic Kit - Test The Microphone System Outside The Body
Tamara Rurkovska RM-5 Bb-P26 Mic Booster DIY Kit

Very Low Shipping Fees for any Destination Worldwide

We deliver with UPS/Fedex/TNT to any place worldwide. The delivery fees are fixed and do not depend on weight and volume of your order.

The Shipping Fees are as Follows:

If you still have any questions regarding the RM-6 Ribbon Mic Kit, don’t hesitate to write me. I normally reply within few hours and I am always happy to chat with the fellow DIY audio enthusiasts.