Bumblebee Pro Audio

RM-5 Ribbon Microphone Kit

$250.00 $299.00

  • Full Kit
  • Step-by-Step Guide
  • Supported
  • Beginner

Artur Fischer's RM-5 is a classic, figure-8 ribbon microphone featuring modern, custom-designed components manufactured in Latvia. The RM-5 shares the warm and rounded tonal qualities associated with its vintage counterparts. However, at it's core the RM-5 is simply an exceptional transducer, capturing every source, from gritty electric guitars to hushed vocals, in a way that is natural, detailed, and balanced.

The RM-5 features the same stainless steel body and gold-plated XLR connector as the flagship RM-6 Ribbon Microphone.

To purchase the RM-5 outside of the US and Canada, please visit the DIY Audio Components Store.


  • RE-254 ribbon transducer made of 2.5µm Japanese aluminum foil and neodymium magnets
  • Custom RTP-35 transformer designed specifically to complement the RE-254 ribbon 
  • Microphone body machined in Latvia of hand-selected stainless steel and matte polished for Bumblebee Pro's signature finish
  • Custom XLR recepticle with gold-plated pins for decades of reliability

DIY Friendly

The RM-5 kit is designed for beginnersyou don't need any mic-building experience to successfully complete the build. The required tools are a soldering iron, some solder, and a hex wrench (Allen Key) set. The entire assembly includes only six solder joints. To ensure world-class performance, the kit comes with the RE-254 ribbon transducer pre-assembled and hand tuned. And finally, the kit is backed up by our friendly Guaranteed Support.

Kit Includes:

A shock mount is not included. The SM-28 is sold separately here.

  • RE-254 ribbon transducer (pre-assembled)
  • RTP-35 transformer
  • Stainless steel microphone body and mounting hardware
  • XLR insert with gold-plated pins

What is the difference between the RM-5 and RM-6 DIY Ribbon Mic kits?

The RM-5 and RM-6 are two different designs, they just share the same type of body. The main differences are:

  • RM-5 is a big ribbon mic with a 2″ ribbon; RM-6 is a small ribbon mic with a 1″ ribbon
  • As is typical for shorter ribbons; RM-6 has less distortion and sounds more "natural"
  • RM-6 has a slightly flatter frequency response than the RM-5
  • RM-6 has significantly higher output signal level, at least +3dB higher than RM-5
  • RM-6 has much lower magnetic flux leakage; there is practically no attraction between two microphones standing side by side
  • RM-6 motor comes with a 1.2u ribbon, while the RM-5 motor comes with a 2.5u ribbon
  • RM-6 comes with RTX-28 toroidal transformer optimized for thinner foil gauges

The samples below demonstrate the RM-5 on a range of sources. The acoustic guitar was mic'ed with RM-5s at the bridge and 12th fret. Electric guitars were double tracked; the "Soft Overdrive" was mic'ed with the RM-5 8" from the driver, on-axis while the "Hard Overdrive" was mic'ed with the RM-5 10" from the driver, slightly off-axis. The accordian was recorded with the RM-5's in a Blumlein pair configuration about 2' from the instrument. The brass quintet and church organ were recorded in The Netherlands by Jo Smeets in a Blumlein configuration. The harmonica was recorded with the RM-5 about 8" from the instrument.

Customer Reviews

Based on 16 reviews
Andrew Moore
Great ribbon mic

I enjoyed using this mic and enjoyed the build. I definitely used a high pass filter to help with the enhanced low end of the mic, but I knew that going into it thanks to the other reviewers. Very clear sound when recording violins last week.

Raven Tenderfoot
6 solder points. One is a bit nerve wracking!

The hardest part for me was getting the top and bottom cap off. This is because the mic was in my mailbox in 30 degree weather. Place mic in front of a space heater for 20 minutes or just wait a few hours before starting to build. Physics is annoying. After that, everything was pretty smooth. I carefully would twist the wires, and then untwist if one was too long, that meant the twist wasn't even. No trimming required, though each took 3 redo's. The wires felt a little flakey but I think it's just an outer coating. I'm a super beginner with a sloppy hand. The capsule was nerve wracking as not much area for the first wire. However, I nailed it first try. The mic is bigger and heavier than expected. I didn't notice the shock mount is separate. The verdict: next pay check, I'll buy a 2nd mic. It's sounds great. The price is super reasonable. The build is simple. It's always good to have a stereo pair. Find a cool sticker so you can mark which side is the front as there is no engraving. I glued a cap over my phantom power button on my Iron Age Audio quad pre. This will live on channel 4. I plan for these to be drum over heads (after I get a 2nd one.) I'll likely buy the RM-6 for guitar. Warning: Extremely Addicting! This is my 2nd DIYRe. My first was the ReAmp. That thing is awesome. I want DIYRe to make a mic splitter and a 4x1 mixer.

Jawad I.
Excellent gift.

Bought this a year ago for a friend. He wanted a ribbon microphone at the time and he likes to solder his own equipment. I've heard him use it but I don't have enough of an idea on how it sounds but he seems pretty happy to have this mic. Anyways he said even if you're a beginner in soldering it's not too difficult to solder these so great gift. Just be sure to tell others not to blow at the mic to cool down the solder because you know, it's a ribbon mic. Easiest to build and easiest to break.

Shane H.
Great Mic!

I failed the first time with this kit because the older transformer broke during the build. Support from DIY/Artur was great. They sent me a new transformer when I failed with the first one. The new transformer fits right into the body of the mic and makes the build process very easy. This kit was ready to go within 20 minutes. This mic sounds amazing. I plan on ordering another one in the future.

Stefano Bonzi
Finally super easy to build!

I failed 3 times because the older transformers kept breaking during the build. Artur made it finally super easy with a transformer that is practically impossible to break and fits right into the body of the mic. Soldered 4 points, screwed the top and bottom and I was ready to go in 20 minutes. What an amazing sounding mic this is! I can’t wait to buy the RM-6 and probably I’ll go for 2 matches pairs.

Related Products

Liquid error (layout/theme line 342): Could not find asset snippets/hulkapps-restock.liquid