3M Dual Lock and Attaching Your Player to a Portable Headphone Amp Page 3

HeadAmp Pico Slim and Dual Lock
The HeadAmp Pico Slim is a very small headphone amplifier. If there was ever an amp that might be attached to your iPhone and still be able to fit in your pocket, this would be it. But until I started playing around with Dual Lock, I could never figure out how to accomplish it cleanly. Velcro just wasn't stable and secure enough for me, and rubber bands won't work because the amp is so small the bands would have to cover the iPhone display.

Just before I left for CES, I decided I simply had to have a high quality portable rig that would fit in my pocket. I decided to revisit Dual Lock as a potentially useful material when the case-cutting idea came to mind. In the case of the HeadAmp Slim with its leather case and iPhone in Otterbox Defender, it worked perfectly!

Here you can see the hole cut into the Otterbox case and the Dual Lock within. You can also see I've done a similar thing with the HeadAmp Pico Slim leather case. I removed the Slim and replaced it with pieces of cardboard the right size to fill the case. Then, like with the Otterbox previously, I sliced open a hole in the case the right size for the Dual Lock strip. I then removed the cardboard and replaced the Slim in the case, and adhered the Dual Lock strip to the Slim through the hole.

In this set-up, the Dual Lock is only slightly above the surface of both products providing a clean look when apart. But there's just enough room to "snap" the two together when joined. Because the cases take up about the thickness of the joined Dual Lock, there is no gap between the iPhone and Slim when snapped together.

Oh snap, is right! This is a sweet little rig that fits in my Hawaiian shirt pockets, and easily into a jacket pockets. It also leaves the rear camera of my iPhone open to view. Man, I love this little piece of kit.

HeadAmp Pico Slim and iPad in Otterbox Defender
Now having a Dual Lock strip on my Pico Slim, I figured I'd find a way to attach it to my iPad. It is also under the protection of an Otterbox Defender. There is a removable sliding door that opens to allow the connection of the charging/sync cable. There's just enough room in the opening to allow the Slim to attache right next to the connector. It did have a little clearance problem, so I used an Exacto knife to cut away a little padding on the back of the door to make room for the thickness of the Dual Lock.

Now it's Your Turn!
I'm quite excited about the possibilities of using Dual Lock in portable rigs, and while it's not the perfect solution for every portable headphone rig, it's certainly one more tool available that might help to rig up a really sweet portable listening system.

If you just have silicon cases over your player, you can cut holes in it and attach the Dual Lock directly to the player through the hole. The low profile Dual Lock might be great for sticking a stack together without cases as it's so thin. Rubber bands work great as bumpers. In some of the threads I read, it was suggested to slice old inner-tubes to make rubber bands, and many enthusiasts use the rubber bands found around asparagus and broccoli in grocery stors for the task. I've also included a couple of links rubber band sources in the resources below the video.

3M Dual Lock mini-site.
All About Dual Lock info page with some good tips.
Purchase Dual Lock at the iTapeStore, or The Binding Source.
Thick silicone bands from ALO.
Cheap place to buy wristbands that might work.
Old school crepe rubber bands in various sizes.
A couple of short Head-Fi threads that mention Dual Lock here and here.
Otterbox Defender Series cases.
And the spectacularly cool Pico Slim ($399 .... and worth every cent, if you're an addict like me).

3M Center
St. Paul, MN 55144-1000

4nradio's picture

Thanks for these do-it-yourself tips, Tyll.

I wasn't aware of the 3m Dual Lock product but have used Radioshack "Superlock" strips for years. It is very similar to 3M's offering and may be easier for some folks to find. It is RS catalog #64-2360 and costs $3.99 for two 1" x 3" strips. You certainly don't need to use much due to its high tensile stength. Like with 3M it is also best to let the sticky-backed adhesive set for a couple of days before pulling the gear apart.

13mh13's picture

Luv da way TH *strains* to SNAP the DualLock'd pieces apart. Good thing he has those $$$ OtterBox ... uh ... "strain reliefs" LOL!!!

I have a horror story about using the death-grip-like DualLock (Radio Shack variety) ... resulted in cracking an iPod PERMANENTLY out of commission. But that gave the person an excuse to buy a HiFi-Man DAP. The 3M-HiFIMan conspiracy! LOL!!!!!!!!!!!!!

But Descarte's Evil Demon would wear the High-end-audio-journalist's horned baseball cap ... and say:
"Highly Recommended"


"Be of Sound Mind", folks.

metalsonata's picture

I wanna know what all that stuff is strapped to the poor bloke above. Looks like some sort of cyberpunk nightmare.

Tyll Hertsens's picture
That's Si Burning, and yes he did regularly wear that rig around Manhattan. Left to right is: a gel cell battery pack; the gray tube is spare batteries for the CD player; the CD player above; then a pouch holding an iRiver IHP hard drive player with digital out; then I think he has a HeadRoom Portable Micro Amp w/DAC under the player in the bag. The iRiver remote is clipped to the strap.
metalsonata's picture

...pretty much the only thing I can say about that rig. Imagine trying to get something that looks like that through airport security today.

13mh13's picture

Some of the now-CLASSIC Stereophile ads -- ca. early/mid 90s -- were not much ... uh ... "worse". BETTER IMHO ... those had character.
Now ... yawnsville and totally UNmemorable.
Technological "improvements" = miniaturization + form-factor-"improvement". Now, folks can stick their iPods in their Fruit-of-the-Loom DRAFTS ... and walk around LOOKING totally normal ;)
No more individuality -- everybody's off the same assembly line. Same song, different day. Work with me on this, folks.
Speaking of underwear + normal ... how far would YOU go to for your company ...

Merck's picture

Wow that stuff really seems to work very well. I will definitely keep this article in mind when I build an awesome portable rig with the CLAS.

CarlSeibert's picture

They marketed this stuff to photographers as far back as the eighties. I have strobes from back then with patches of "PhotoLok" to hold slaves and they still work fine.

My laptop dock at work is held together with about 2 square inches of it and it's not going anywhere.

Believe Tyll when he says you have to plan for the thickness.

allmotor91's picture

Did you make those short iPhone to amp connectors or can you buy them? Awesome write up about it. Love the DIY stuff.

mikemercer's picture

You can buy those LOD cables (cables coming from the iPod/iPhone) from ALO, or Moon Audio, Whiplash Audio makes them as well!

GREAT write-up as always Mr. Hertsens!!