Should be well established by now I’m a bit of an audio geek, however I’m the geek that doesn’t believe good audio costs a lot of money. On the other hand I think you have to have a hand in the configuration and the tweaking to get the sound that you want.

Before I get into the nuts and bolts.........A history lesson.

Anybody that follows audio knows the story of NwAvGuy. A poster at who was banned. I’m not real familiar with the story and don’t care but the NwAvGuy made a DAC he called the Objective DAC and an amp called the Objective 2 (O2). His basic premise was that overpriced audio was just that and he made and released the plans in an open source format for the audio community. Translation: ODAC and O2 were very good and very affordable. We can, and they did, debate this ad nauseum, on Head-Fi and other places around the net.............. The NwAvGuy mysteriously disappeared after releasing his plans and blogs. What, in my opinion, that he accomplished was to DRAMATICALLY reduce costs all across the audio world. I mean who is going to pay $500 for a headphone amp or DAC when you can make one yourself, or buy one from someone with the open source plans for chump change. Hey, competition. Thank you NwAvGuy where ever you are.

Anyway this leads me to a place called JDSLabs. JDSLabs built and sold the ODAC which after all the fanfare I purchased a year or more ago. It’s a fine DAC and it performs very well in my Dynaco ST70 Tube Amp, Bottlehead Foreplay preamp, LS3/5A speakers system. It’s a keeper.

Anyway I’ve been eyeballing another kit on JDSLabs forever called the CMOYBB. It’s a headphone amp in an Altoids tin can. Here’s the history lesson for the CMOY headphone amp. It’s worth a read.

i always wanted to build one but thought “this has got to be like a Radio Shack crystal radio kit”. I figured it looked cool but sounded bad. A few months ago I finally broke down and ordered the kit instead of the pre-manufactured amplifier. What fun is it to buy something like this when you can build it yourself?


See the circled region below? That’s called an opamp.


The stock opamp chip in the CMOYBB is an OPA2227PA chip. Before we go any further let me state that it sounds mighty fine. This inexpensive little kit in an Altoids can will blow your mind with the quality of audio reproduction.

Trust me, it is amazing.

Now here is the fun part. There are a multitude of tweaks you can perform to this circuit. One of the easiest things to do is just change the OpAmp. Here’s what I did. I ordered a MUSES01 OpAmp and installed it. Before you wanna be like me and get one you might notice the link is mostly in Japanese. Lucky me, I currently live in Japan and can have them shipped to my home. Now for the bad news. They require about 9volts to operate cleanly. The CMOYBB circuit with one battery installed gives you about 4.5 volts to the opamp. Sooooooooo you add another battery in series and install the MUSES01.


Even though my wiring is in the way that is an authentic MUSES01 from Japan Radio Corporation (JRC). Beware buying one on the internet. There is a LARGE market for fakes. A real MUSES01 is at a minimum going to cost you $35. A smart rebrander can take a chip that costs a dollar, sand it down a little, and silkscreen new markings on it. Matter of fact the first one I ever bought was a fake (from an Amazon Japan web dealer).

Anyway you won’t believe your ears. Okay the kit cost $42, and couple rechargeable batteries costs $20 and the MUSES01 chip was $35. I’m quickly getting out of the economy zone here. However I’m right around a hundred dollars for some ridiculously fantastic sounding audio.

Okay, so you don’t know how to solder and you sure don’t know how to wire two 9v batteries in series to produce 18 volts but you still want to play. No worries. Buy yourself a pre-manufactured amp kit and change to another chip that doesn’t need an additional voltage boost.

You want the AD8620ARZ chip. You can go to this website and order a Brown Dog Adapter. Go to the right side of the page and hit the drop down box for “Add Pre-Mounted Component”. And then add the AD8620ARZ. $22. I’m positively blown away with this combination.

Which one is my favorite? I don’t know. They both sound great. The MUSES01 incurs a little more expense and if you want to charge the two 9V batteries in place you need to buy a 24volt charger and adapter incurring even a little more expense.

i think the AD8620 chip gives you 95% of the MUSES configuration but hey, that 5% of better sound is what it is all about, isn’t it?

CMOYBB - Stock Chip = Great
CMOYBB - MUSES Chip = Great
CMOYBB - AD8620 Chip = Great

There’s really no losing here. Just do it. Just buy one of these amps. Use it as is or swap chips. I’ve not even scratched the surface on available tweaks either.

And for God’s sake get a decent set of headphones. Everything will sound like crap with crap headphones. I strongly recommend the Sony MDR-V6 headphones. Best headphones in the land for about $65. My link says $82. Shop around they can be had cheaper. I got a used set once on eBay for $35. Brand spanking new looking too.

And hey you can put these in different tin cans as well.


And it looks pretty cool strapped up and hooked to your iPod.