UPDATED: So You Want A Good Cheap Ribbon Mic: Upgrading the $69.99 MXL R40

UPDATE: since this article seems to get an enormous number of pageviews, I thought I should mention that we did in fact carry-out the intended shoot-out of the mod’d R40 versus a range of other similar ribbons (with a Royer R121 as the ‘control’ sample.  CLICK HERE to listen to some apples-to-apples action.

I love the sound of ribbon mics.  Friends and clients will often ask me why, or ‘what’s the difference’ (b/w a ribbon and other forms of mics) and I generally reply that good ribbon mics seem, to my ears/brain, to reproduce sound in a way that more closely resembles the actual event.  To my ears, a good condenser like my U87 or U47 FET sound fantastic – more spectacular than the actual sonic event, in many cases – and a good dynamic mic like a 441 or an SM7 can really improve the sound of an electric guitar speaker – but there are ways that they do seem distorted, especially on material with complex, aggressive high-frequency content, such as cymbals played with a heavy touch.  Ribbon mics also seem to respond better to additive EQ, and on bass instruments they also seem to create the impression of bigger, fuller bass without actually taking up as many DBs in the mix as you might expect.  Anyhow, I keep writing ‘seem’ because all of this is, necessarily, subjective.  That being said, these are opinions that more and more recordists and musicians have come to share since ribbon mics came back into vogue a decade or so ago.

FOLLOW THE LINK BELOW TO READ-ON AND LEARN HOW TO MAKE YRSELF A REAL-NICE SOUNDING RIBBON MIC IN 45 MINUTES FOR UNDER $100…

Although condenser microphones were actually invented a few years before the first ribbon mics, ribbon mics are interesting in that they really haven’t changed in design since the 1920s.  Whereas today’s garden-variety condenser mics are much more sophisticated and hi-fi than their 1920s ancestors. A standard ribbon mic consists of a physical body or shell, a thin metal ribbon suspended in a metal frame alongside a magnets, an output transformer and output jack.  That’s really it in most cases.  And with these very few elements, sound can be turned into electricity with incredible realism.

Royer Labs claims to have been responsible for starting the uptick in popularity that ribbons have seen since the millenium; their R-121 was introduced in 1998 and sure enough it’s a great microphone.  I’ve owned one for years and yeah I use it on pretty much every session.  It sounds great, it has a lot of output, it’s very small, and it has survived a few 4-ft drops onto the oak with no ill effects.  It’s a very good product, if a little overpriced IMO (check out the Shinybox 46MXL for a mic that’s 98% as good for 40% the price of the Royer; I’ve used my 46MXL on sessions with my Royer for years).   Also shockingly good: the Cascade Fathead Two.  I bought one of these a few years back just to see what the fuss was all about, and while it’s not going to replace my Royer, or my vintage Beyer, Shure, and RCA ribbons anytime soon, it’s really pretty remarkable for a $200 microphone.  One caveat: with no apparent cause, my Fathead II has developed a slight slack ribbon which causes an audible rattle if the mic stand is bumped hard.  Now, realistically, if a mic stand gets bumped, you prolly have a bigger sound-problem than a rattle -40db below program level but it’s important to mention. 

Ok but let’s say you don’t have even $200 to spend on a microphone.  I sure didn’t when I started taking recording-studio classes in college.  There are a number of cheaper alternatives to the Fathead II, and I’ve tried many of them over the years, driven mainly by curiosity.  Mics in this category that I cannot recommend: The Nady RSM4.  Chalky, low output.   The Oktava ML52 (expensive now, but these were intially as cheap as $150 at GC): just awful.  So when I got some sort of promo-mailer from Musician’s Friend touting the “MXL R40 Ribbon Mic $59.99” (still avail for $69.99).  I figured: what the hell.  Worst case scenario, I’m buying a sixty dollar shockmount.

So the mic came and it didn’t suck.  The output level was not so good but the sound was cool in a midrange-y, vintage-LP sorta way.  Way, way better then the Nady.  But not a very modern-sounding mic, so application would be limited.  You read some other folks’ assessment of the stock R40 at this link.

I remembered that EDCOR made a 1:37 ribbon mic transformer that only cost $23 and promised perfect frequency response.  I ordered one along with some other bits and bobs that I needed from America’s premier manufacturer of low-cost audio transformers, and a month later it arrived: the RMX1  (see here for spec sheet: RMX1).

EDCOR makes some great products, and some not so great.  Search for EDCOR on this site and you can see many, many opinions of mine regarding their various wares.  That being said, I am a big supporter of theirs, because the products are all made in America, carefully packaged, well supported, and really an incredible bargain if you use them correctly.  As for the RMX-1: I am giving this product the full two thumbs up.  WOW what a difference it makes in the MXL R40.  Here’s how I did it:

With 8 turns-of-the-wrist the R40 opens up to reveal a 4-point terminal board positioned above a transformer housing.  Above, two wires extend from the head (these be the two ends of the ribbon, I imagine…) into the body cavity.

Here’s the reverse view.  This is the original factory transformer.  It has two primary wires and two secondary wires.  The EDCOR RMX1 is EXACTLY the same size and fit in pretty easily once I removed some of the shrink-tubing that EDCOR used to protect the exiting wires.  Other than removing some of the shrink tubing and re-securing the wires with electrical tape there was no mechanical work to be done.  Simple.

The wire color-codes on the EDCOR don’t match the colors on the stock transformer, so I drew the above schematics in my super-embarassing ten-yr-old-boy handwriting.  Feel free to laugh at my apparent total lack of fine motor control.  ANYway, that’s about it.  Sub the new trans in for the old, solder the wires to the correct places on the terminal board, and yr done.

Here’s how it sounds, recorded right into ye olde MBOX2.  You are hearing a solo finger-picked acoustic-guitar performance of a gospel classic.  Put on some decent headphones and take a listen.  First, the original transformer, with 4.6 db of gain digitally added (no other processing whatsoever):

LISTEN TO ORIG TRANS WITH 4.6 DB ADDED: MXL R40 Original Transformer plus4pt6db

…and after I did the modification, which took 45 minutes…  here I am with a 2nd performance, same mic position, same input level on the MBOX, etc…  but with no gain added:

LISTEN TO EDCOR TRANS: MXL R40 Edcor Transformer

Was this test scientific?  No.  I could have been a little off-position for the 2nd take.  I could have played a little harder.  Sure.  But this is a dramatic difference.   It feels like there is a whole additional octave both top and bottom with the EDCOR;  it also sounds smoother and more polished.  Plus I had to add 4.6 db of gain to get the original transformer take at the same average program level.  That means that the mic’s output with the EDCOR is around 50% louder in volume.   These are substantial improvements for an easy-to-install $23 part.

If I ever get the chance, I will do some sort of listening-test in the studio with this modded MXL, the Fathead II, the Shinybox, and the Royer.  Don’t hold yr breath on that one tho…

Further Reading

Michael Joly (ribbon microphone upgrade service-for-hire) ***

DIY Ribbon Mic Kits and Plans ***

Ribbon Mic Rennaisanse coverage in the popular press (c/o WIRED)

( *** n.b: I have no experience with these companies/services, but it’s interesting reading at the least)

PREVIOUS RIBBON MIC COVERAGE ON PRESERVATIONSOUND DOT COM:

Vintage RCA Ribbon Mics (the standard in professional American ribbon mics)

The American R331 (an obscure American ribbon mic from circa ’50)