DIY Ribbon upgrade for MXL 990 Microphone

Hello, I’m beginning my personal little crusade in the Ribbon Mic arena.

To start, I’ve created an Instructable, to upgrade an MXL 990 condenser mic with a ribbon element from www.diyribbonmic.com/parts

I created some 3D printed parts to hold the ribbon element and transformer.

But I think one of the key things is I also created a 3D printed ribbon alignment jig.  It makes it really easy to replace and re-ribbon the element.

I’ve already gotten a ribbon alignment jig designed for the MXL R80 and MXL R144 mics. I’ve re-ribboned the R144, and replaced the transformer, and it sounds a billion times better.  I have re-ribboned the R80, and redesigned the element placement and holder (to make it symmetrical) along with a new transformer as well. Very pleased with that too. I will post these updates to Instructable and Thingiverse shortly

In the meantime, please check out my instructable, and parts on thingiverse.

http://www.instructables.com/id/Ribbon- ... r-MXL-990/

http://www.thingiverse.com/thing:1271932

Next big project is a resonant tuner for ribbons.  Currently planning a 3D printed frame, which will support interchangeable ribbon modules (so you can use the same tuner for Austin, R80, R144, and others as I design them).  You pick the resonant frequency  0 to 200Hz, and a stepper adjusts ribbon tension until it is dialed in. That's gonna take a few months, so I just wanted to get these out there.

Enjoy

Thanks.

Wherever you copy-pasted the content of the post from (after making the actual post, as opposed to the content), it cut off the actual link itself to Instructables Some forums do that, so mile-long "link texts" don't end up in the posts themselves.

That looks a bit more credible

On ribbon tuning... one issue we had is that during the tuning process the ribbon is not  solidly electrically hooked up
so we can't drive it like a speaker. What we did was to make a volume velocity source from an unbaffled woofer.
We place our ribbon carrier fixture on that while adjusting the ribbon lightly adhered to the clamp with alcohol.
Driving the source with an oscillator easily can get 4 mm excursions from the ribbon at resonance. We also watch it with a strobe light to look at unusual motions from tiny edge tears, etc.

After tuning and clamping we run a batch of ribbon carriers on the unit at very high amplitude for an hour or so to condition
and test for early failure.

Our actual tuning is by hand but you could easily servo it...detect motion with optical or capacitor sensor...

Les

I was playing around with an apex 210 ribbon and a signal generator app on my IPhone, and just hooked it up using alligator clips and a cable.  I hooked the alligator clips up to  the terminals on the ribbon side of the transformer. 

The ribbon didn't move until I got below 60hz, and it moved significantly at that point and below, before settling down again at some point. 

What are you looking for when you tune these?  I felt like the largest excursions were at 20 something hz, but to be honest it was hard to tell

We're a manufacturer. We tune to very specific values... typically 35 to 40 Hz.
At resonance and harmonics you'll see a large increase in motion.

Many of the low cost ribbons are tuned too low and/or not conditioned properly. The result is a slack ribbon that
falls out of the gap or touches the pole peices.

Les