n-eight wrote:

m.koren wrote:

n-eight wrote:I re-ribboned my Shinybox 23 with some foil liner from a soft pack of cigarettes (the cheapest I could find, as it usually has thinner foil)

What brand ? I had a hell of a time with signwriter's leaf and I'm looking for something that will actually give a decent output.

I think they were Doral or something. I'm not a smoker so I didn't pay attention. I just asked the guy for the cheapest soft pack he had. He handed me these and said, "They're two-for-$5 today" and I said, "No thanks. Hopefully this will get me through my project." He looked very puzzled as I paid him.

Trying to explain to my wife why I was dismantling a pack of shitty smokes was fun too. "I'm trying to fix a microphone" didn't really cut it for her. Then I threatened to smoke them all at the same time like that "guinness book of world records" dude. She left me alone after that.

So... yeah. Doral.

Thanks for that. Also wondering if a scalpel work better than an exacto knife ?

Wow. I'm humbled by all the discussion of my DIY Ribbon Mic project. I just discovered this forum on a Google search of "Austin Ribbon Microphone" - Previously I didn't know it existed.

First off, let me say that the AUSTIN Ribbon Microphone is a DIY project, not a production-worthy design. My goal was ease of assembly and acquiring parts for the weekend DIY'er. It was not meant to compete with a Royer, AEA or Crowley & Tripp. However, it does pretty well. (See the specs)

Now, I'll try to answer some of the questions that have come up in this forum.

Metal vs. Plastic Truss Assembly
I too, attempted my first designs with metal. Brass U-channel to be exact. With 4 pieces that make-up the basic truss, I couldn't get my drill holes to line-up so that the pieces were all 90-degree angles. Also, if there was any stress, the truss would "rack" to a parallelogram instead of a nice rectangle. So after I failied at making a truss out of Legos (!!) I went with square acrylic rod, glued together. All the 90-degree angles line up nicely, and you can get the angles right while the glue is still setting. Plastic rod is non-conductive, non-magnetic, and cheap too.
I've made ~10 trusses with this method, and they only times they have failed are when I was trying different adhesives (Super-Glue and Epoxy don't work!) and after falling from an 8-foot mic stand (ouch!)

0.6 Micron Aluminum Leaf vs 2.5 Micron Foil
Again, ease of acquiring parts was my motivation. Al leaf ("Gilding leaf", etc.) is widely available online, and at some art supply stores, and is very cheap for the amount of material you get. Working with 0.6 Micron Aluminum is not easy, but it's not terribly difficult if you have some patience and you are prepared to make some mistakes. It can be done, I'm living proof.
The other thing I've read is that thinner foils give better high-frequency response and higher output. Admittedly, I have never used any other foil, so I don't have a reference.
I tried the Cigarette foil method too, but it was a giant pain for me. Maybe I did it wrong?
Lastly, I'll give away a trade secret: You can get thicker foils at good prices here: http://lebowcompany.com/foils_list.htm#ALUMINUM 
Theoretically, a single $25 8x8 sheet could yield 50+ ribbons.

Designing the Chassis
Brass is easy to cut and is non-magnetic. Aluminum would be similar, but I haven't tried it yet. When properly grounded, a Brass or Aluminum chassis acts as a Faraday cage to keep out stray noise. Plastic sprinkler pipe doesn't.
We are all thinking alike. I am now researching some Chinese Chassis' because I am a hack with a hacksaw and Dremel. (Not that you can tell how the mic looks when listening to a recording) My design works, but frankly, the Chinese make a nicer looking chassis than I can.
I've designed an Austin Ribbon mod for the very cheap MXL-990 ($25-$50 on eBay) but it's not available yet. Sorry, again my life usually interrupts my hobbies.

Looking Forward with the Austin Design
For your $100-$150 in parts (depending on the transformer) the Austin mics are fairly easy to build and sound pretty amazing. However, between my family, day job, and an electric guitar addiction, I just don't have time to build them... So I'm constantly looking for ways to make the build take less time.
I don't want to give away all my secrets just yet, but I have some ideas for the next revision that could take this project from a 10-hour investment, down to a 2-3 hour investment (not including epoxy curing time.) Pre-fab ribbon trusses and using someone else's chassis are a big part of that... But I'm saving them for the next revision of the DIY Austin Ribbon Mic Plans.

Ask me any questions... I'm all about helping people learn.

- Rick
www.RickshawRecords.com

Hey Rick

Just to let you know. I didn't mean to make this a "dis" the Austin design thread. So I hope there's no offenses included in here. In fact I tried to keep the actual name of your kit out of it - in case the thread took a negative turn and or abusive turn.Which happens in these forums sometimes, though usually not in the "techroom". Also I've not posted much about your designs in order to protect your ebay sales.

Anyways welcome.

Cheers
Doug Grean

Doug,
No "diss" implied. Thank you for your original post.

Hopefully I've helped inspire discussion and DIY!!

- Rickshaw

Glad you found us.

rickshawrecords wrote:Working with 0.6 Micron Aluminum is not easy, but it's not terribly difficult if you have some patience and you are prepared to make some mistakes. It can be done, I'm living proof.
The other thing I've read is that thinner foils give better high-frequency response and higher output. Admittedly, I have never used any other foil, so I don't have a reference.

As I said earlier, I haven't built my mics based on your design yet, but I have some experience handling foil leafs, so strangely this is the least of my worries. [these are the words that will come back to haunt me - I know it already].

One tool that you didn't mention in your instructions but that's key to handling foils for art applications is a long-haired fro-pick-like brush. It may even be called a gilder's brush for all I remember. It's an extremely useful tool for moving thin, fragile pieces of foil around and positioning them precisely. The key to using the brush is introducing the slightest amount of oil to the surface, usually done by dragging the brush across your nose or forehead for 2 strokes before picking up a leaf of foil. Once you've done that it's very easy to pick up the leaves, move them around, position them, etc. It's a useful tool.

"long-haired fro-pick-like brush"

What like from the 1970's? Should firm plastic teeth or more like a painters brush?

Where can I buy one? art supply or beauty supply store?

Here we go:
http://www.gildedplanet.com/gildingbrushes.asp

The one I have has a thinner array of hairs and I think it's ermine, not squirrel, but the idea is the same: fine-tipped hairs.

You can probably find them in an art-supply store, but I'd call first. Not many people do gilding, so it's not like they would sell a lot of them.

Uncle Ovipositor wrote:One tool that you didn't mention in your instructions but that's key to handling foils for art applications is a long-haired fro-pick-like brush. It's an extremely useful tool for moving thin, fragile pieces of foil around and positioning them precisely.

OK, I was saving this for the next revision because the technique is not perfected yet, but I'll give this away now since ribbon handling is being discussed:

I use a drawing compass.
Imagine a compass with sticky-tape on each point, which you can open/close to adjust the tension. (Sample image from Wikipedia here)
I bought a compass with Brass tips (non-magnetic) at Office Depot (USA) for $10.

I "grab" the corrugated ribbon with the tape on the ends of the compass points, expand the compass to properly tension it, set it in the gap, and tighten the clamps.

The 2 issues are:
1. A compass opens in an arc, not a straight line - so I have to guess the amount of expansion, and make sure the ribbon ends-up fairly straight instead of pulled tighter on one edge.
2. Sticky tape doesn't let go - you have to sacrifice the ends of the ribbon. I've thought about attaching the clips which I use in my DIY ribbon plans, but I haven't tried it yet.

So, I hope this helps inspire some of you. It's not perfect yet, but for me, it makes handling fragile ribbons WAAAY easier that floating them in by hand.

- Rickshaw

rickshawrecords wrote:

Uncle Ovipositor wrote:One tool that you didn't mention in your instructions but that's key to handling foils for art applications is a long-haired fro-pick-like brush. It's an extremely useful tool for moving thin, fragile pieces of foil around and positioning them precisely.

OK, I was saving this for the next revision because the technique is not perfected yet, but I'll give this away now since ribbon handling is being discussed:

I use a drawing compass.
Imagine a compass with sticky-tape on each point, which you can open/close to adjust the tension. (Sample image from Wikipedia here)
I bought a compass with Brass tips (non-magnetic) at Office Depot (USA) for $10.

I "grab" the corrugated ribbon with the tape on the ends of the compass points, expand the compass to properly tension it, set it in the gap, and tighten the clamps.

The 2 issues are:
1. A compass opens in an arc, not a straight line - so I have to guess the amount of expansion, and make sure the ribbon ends-up fairly straight instead of pulled tighter on one edge.
2. Sticky tape doesn't let go - you have to sacrifice the ends of the ribbon. I've thought about attaching the clips which I use in my DIY ribbon plans, but I haven't tried it yet.

So, I hope this helps inspire some of you. It's not perfect yet, but for me, it makes handling fragile ribbons WAAAY easier that floating them in by hand.

- Rickshaw

Hmm. That's a good idea, thanks. I may try that with my jewelers saw. It opens and closes and clamps. So you could adjust the tension and then clamp it down.

http://wire-sculpture.com/items/G18_3.php

I'll let you know if it works. It might be too heavy/cumbersome.

On second thought the compass looks better because of the fine adjust of the gap.

Maybe I'll try and make a ribbon tensioning tool. Wouldn't be that hard. Would it?