Crystal cMoy Freeform Headphone Amp

April 22, 2012 1:43 PM

Making a crystal cMoy freeform headphone amp: 1 2 3 4!
posted by jjray (30 comments total)

Very cool! I love seeing the history of electronics tinkering before things got more streamlined. Like this.
posted by mccarty.tim at 2:13 PM on April 22, 2012 [1 favorite]

I mean, what people did before PCBs/breadboards.
posted by mccarty.tim at 2:13 PM on April 22, 2012

Really cool, I wish I could buy hardware like that. I'm also somewhat fascinated by the extremely poor grammar by this guy.
posted by rowancluster at 2:18 PM on April 22, 2012

I would have added more LEDs. Maybe something that would change colors depending on the stereo balance, or if you wanted to add more chips you could have different colors or multiple indicators depending on the frequencies present in the signal
posted by delmoi at 2:22 PM on April 22, 2012

I've not read the article, only looked at the pictures. So I don't yet know what it does but I already want one.
posted by benito.strauss at 2:46 PM on April 22, 2012

That is seriously cool. Beautiful work. I'd love to have one of those on my desk.
Sadly, it appears not all of his pictures are working. There seem to be blank spaces.
posted by Thorzdad at 2:49 PM on April 22, 2012

This would make a fantastically rugged guitar pedal housing.
posted by hanoixan at 2:50 PM on April 22, 2012

Does it dissipate heat at all?
posted by GuyZero at 3:10 PM on April 22, 2012

So on the last page he mentioned the heat issue - it doesn't dissipate heat but it doesn't generate much either.
posted by GuyZero at 3:15 PM on April 22, 2012

I wish I could buy hardware like that.

Would you be willing to pay over $1,000 for a headphone amp? Because that's what it would cost.
posted by localroger at 3:19 PM on April 22, 2012

Localroger, are you referring to the labor involved? Because it looks like the parts are all pretty inexpensive.
posted by KGMoney at 3:26 PM on April 22, 2012 [1 favorite]

I like his ideas. I hope the design doesn't pick up too much noise or hum though. Its not shielded and all the wires are forming big loops.
posted by Hither at 3:31 PM on April 22, 2012

KGM yes, this is basically a piece of art that happens to also perform an electronic function. Even if he was making identical units all day long with jigs, you would be looking at ten to twenty hours of labor to build something like this. Since it's a prototype he probably invested more like 50 hours. For production he would also have to source some parts that might be hard to find in quantity, such as jacks that can be sealed.

This is skilled labor, and the rule of thumb in industry is that it costs about four times what you pay an employee to set them up for work. I've actually set the company I work for up to manufacture a few small things (we use laser cut acrylic enclosures over circuit boards but the effect is eerily similar) and you would not believe the prices we charge -- and get -- for those little custom boxes.
posted by localroger at 3:34 PM on April 22, 2012 [1 favorite]

> Does it dissipate heat at all?

It doesn't really have to. The original CMoy amp is, as speaker amps go, pretty weak. Maybe a couple hundred milliwatts if you're pushing it hard. It's designed for powering headphones, which are a pair of speakers about an inch from your ears -- most headphones don't need much power.

The circuit elements in the acrylic cube have a lot of space between them. As the builder notes, the resin got hotter while initially setting than the amp has in operation.
posted by ardgedee at 3:39 PM on April 22, 2012

localroger: I don't know. While I agree wouldn't be able to manufacture exactly that unit for anything like a reasonable price, if you used stamped copper wiring with through holes, machine bent and cut components, and an assembly line process you could probably get the total hours per unit down significantly.

Of course then you have to be selling it in large quantities to make all the setup worthwhile.
posted by Grimgrin at 3:49 PM on April 22, 2012

Localroger, are you referring to the labor involved? Because it looks like the parts are all pretty inexpensive.

You said you wanted to buy it, not buy the parts and make it yourself. I don't know if it would take 50 hours of work to make a second one, now that he already knows all the steps (and can re-use the mold pattern, etc) $100-$200/hr seems like a reasonable rate to charge for that kind of work.

You could probably mass produce something like in china that pretty cheaply but things are much more expensive when they're not mass produced.
posted by delmoi at 4:13 PM on April 22, 2012

Peer to peer?

The method and end result looks cool enough. Kind of like wiring up a circuit the way it looks on a schematic.
posted by 2N2222 at 4:18 PM on April 22, 2012

You could probably mass produce something like in china

Yes. Mass production involves tooling, and tooling is expensive; to do the kind of stuff Grimgrin suggests would set you back at least $100K, but you only pay for the tooling once, whereas you pay for the assembly labor for every unity ou produce, so if you make enough units the tooling cost becomes insignificant. The problem with this is your product is no longer unique. Let's face it, one big reason we all wish we had this thing is it'sthe only amp like it in the world. Once you tool up and start selling 'em at Wal-Mart, it's not nearly as much fun to have.
posted by localroger at 4:32 PM on April 22, 2012

You could probably mass produce something like in china that pretty cheaply but things are much more expensive when they're not mass produced.

What I meant: I wish hardware like this was (mass) produced instead of all the crap that's out there.
posted by rowancluster at 4:36 PM on April 22, 2012 [1 favorite]

I don't really think you'd need much tooling to make this. Apple and Foxconn use a manual process to do the assembly for the iPhone because it's more flexible and they don't need to spend a lot of time tooling - it means they can go from design to production really quickly.

The process would be the same as what this guy did, but you pay maybe $2-4/hr, rather then $100-$200. So instead of $1,000 it costs $20. Also, you wouldn't need people as much skill to do the sanding/polishing. You would probably retail it for like $100, though because how many people buy headphone amps?
posted by delmoi at 4:43 PM on April 22, 2012

> how many people buy headphone amps?

Seriously? Thousands of people.
posted by ardgedee at 4:51 PM on April 22, 2012 [1 favorite]

Where he mentions "peer to peer" wiring, and I am thinking he probably means "point to point" wiring.
posted by idiopath at 4:59 PM on April 22, 2012

Holy crap! That is awesome.
posted by caddis at 5:00 PM on April 22, 2012

As someone who recently bought an Objective2 headphone amp, this is an impressive piece of art work.
posted by gen at 6:01 PM on April 22, 2012

delmoi: jfyi, the headphone category of electronics is currently exploding in popularity, most obviously with the popularity of the Beats products, but all headphone manufacturers are releasing more products, higher-quality products, etc. The high end used to be ~$500 but has now crept way over ~$1000-5000 depending on what you want.

The new breed of headphones, amps, and DACs are a revelation: you'll hear stuff that was in your music that you had never heard before. Two good resources are Innerfidelity's Wall of Fame and Headfonia (aside from Head-fi.org.) DIYers should head over to DIYaudio or anythingbutipod.

And your financials are pretty close I think. A regular cMoy is about $60 in an Altoids tin. If someone was to build this crystal cMoy in bulk, I think $100 or so is about right.
posted by gen at 6:08 PM on April 22, 2012 [1 favorite]

A regular cMoy is about $60 in an Altoids tin. If someone was to build this crystal cMoy in bulk, I think $100 or so is about right.

Twice that much if you sand the identification off the op amp.
posted by 2N2222 at 11:58 PM on April 22, 2012

That is so so cool. Even though I don't need one, I would still like to own one.
posted by marienbad at 4:24 AM on April 23, 2012

> how many people buy headphone amps?

Seriously? Thousands of people.

So in other words "practically zero" from the perspective of a mass producer. You would need a big markup on the parts in order to cover the setup costs (i.e if it costs $20k to setup an assembly line, and you sell 500 units, you need to make back $40, plus the cost of the components, labor, marketing, and so on. The "Thousands of people" who buy these things won't all be buying yours.
posted by delmoi at 10:22 AM on April 23, 2012

Clue: Headphone amps likely more popular in Europe, where iPods have their output cut by regulation. Sometimes it's difficult to hear every word of a podcast. I'd happily buy such a product if I knew what to buy and where. Never see anything for sale here.
posted by Goofyy at 1:13 AM on April 24, 2012

Never see anything for sale here.

Well, you know those regulations that make them turn down the iPod output to protect your hearing? I have some bad news...
posted by localroger at 1:46 PM on April 24, 2012