The hero of DIY audio, Pow Chu Moy.

It came to my attention that Pow Chu Moy the man behind Head-Wize and the Cmoy headphone amplifier passed away in Reno Nevada (US)  on February 12, 2016.

Kevin Gilmore was the bearer of the sad news in the headphone community Head-Fi.

I never had the pleasure of talking with Chu Moy, mostly because his forum went down more or less at the time I finally had access to the Internet, but I know a lot of his work, specially the Cmoy amplifier.
Chu Moy is one of those rare online personalities of whom you can’t find a picture via google.
It’s amazing that a man so loved by the DIY audio community never placed a photo online for us to know his face, but something tells me he didn’t want fame or money.
If that was the case maybe Head-Wize would still be around sponsored by audio companies and with draconian rules uphold by professional moderators to protect the flowing of money.

Chu Moy is probably the best example of a true patron of DIY audio. Others tried to emulate his work but they never achieved his fame, after all he does have a amplifier with his name.
All headphone audiophiles know the Cmoy amp and sooner or later some build it or buy it.

Pow Chu Moy is to DIY audio what Sony was to Portable audio in the 80s.
I offer my deepest condolences to his family, with hope they know his importance to all of us headphone enthusiasts.

Update: 21 Out 2016
More shared online about him. 

On innerfidelity.com, the user Jssnow1 wrote:

“I was saddened to hear about Chu’s passing. I attended high school with Chu and just googled his name to see what he was up to and came across this sad news. As there does not appear to be much info about Chu, I can share a little bit. Chu grew up in Chinatown, NYC and attended Poly Prep CDS before going to Yale for undergrad. He was a very nice person. He was reserved, mostly kept to himself, very studious and hard-working. I will attempt to post a picture of Chu from high school (class of ’79). Best”

On lowyat.net, Jssnow1 also shared: 

“Hi, I was very sorry to hear of Chu’s passing. I was a high school classmate of Chu’s and was just trying to catch up with what he might be up to. Foe some background, Chu grew up in Chinatown, NYC and attended Poly Prep CDS in Brooklyn. He was a very serious and good student; extremely straight-laced with excellent principles. A very nice person. After high school, he went to Yale, and I lost track of him after that. I’ll try to dig up an old photo and figure out how to post it. Best,”

powchumoy

On head-case.org  Tyll Hertsens wrote:

“So I decided to call Frank Patten  at the Washoe County Public Administrator office to see if he could tell me any more about Chu.

He was surprisingly forth coming. He said Chu was “traveling light”, and had few if any possessions. He was renting a one-room apartment week-to-week. It was almost completely empty but for an unopened Amazon box with a Bissel vacuum sweeper inside. There was no bedding.  They could find no job or source of income. He did have a PayPal account but the only thing they found is a few contributions to political parties and disaster relief efforts. They found his deceased dad, and they think he had a sister but can’t find her. He was born in New York. He evidently died suddenly and inexplicably.

And yeah, being alone doesn’t mean he was lonely…but boy, it was a little hard hearing that stuff.”

JRC4556, shipment prices and other rants.

Sometimes I really hate living in Portugal, If I want to buy some JRC4556 for my low impedance headphone amp I must pay 18€ of shipment doesn’t matter if it’s 1 or 30 op-amps, if the purchase doesn’t go above 65€ the shipment must be paid.

I get people must get paid to make my shipment but 18€ for some ICs sent via UPS airmail, what about normal mail these days?
I’m not in a good mood because I can’t find that JRC chip locally.
Requested 10 samples to the JRC factory but I really don’t believe they send them to me. Grado uses that 4556 op-amp for a reason, it drives low impedance loads like a marvel even if audiophiles say it’s a piece of shit.

Curious note is the fact many audio companies use it for their headphone stage…yea engineers know better as usual.
I have lots of JRC op-amps but none of them beats the 4556 specs for the low impedance applications.

On a side note I had cold feet about two of my favorite diy headphone amp websites and downloaded both using Wget, I know its wrong to mirror a website but I have a feeling those sites will go down the drain one of these days.

I also download manually some important Korean forum topics made by the amazing Sijosae, about 120Mb of data safely stored for future reference.
Sijosae made amps from 2002 to 2006 and they are really amazing things layout wise. These days I think he enjoys cycling more than headphone amps and I understand him because they guy build almost all diy headphone amps there was to build and also designed some more, so yea I’m sure he got tired of diy.

I must admit one thing, building audio gear isn’t a good idea on the long run, because I don’t want to have tons of gear stored at home, I must think about what I’m gonna do with old projects. Electronic gear is a bit futile, it’s different than building a wood box, a chair, table or any other type of long term projects. Even so it’s really fun to do on my free time so I don’t want to stop now.

Believe or not I didn’t have resources to do this kind of stuff when I was a teen, stores on my area were expensive and I didn’t have the internet to help.

Anyone has some JRC4556AD chips to sell for a decent price? I shall sit down on this one. lol it will be a long wait.

Some thoughts about AC coupling.

Some audiophile remove dc filtering caps from their source devices saying that they degrade the sound of their setups, usually I read stuff like electrolytic caps suck, bass gets cut off, my (insert device name here) does not have any dc problems, my preamp already has filtering and the list goes on.

My questions to those diyers are below.
Do you think the R & D department of the (insert brand here) knows less about electronics than a diy enthusiast, if your answer is yes, I think you should remove your head from your ass, just saying!
Devices stray from specs so even if it doesn’t have dc offset now there is a chance shit will happen later down the road, will you risk your hard earned money because of some Hz in the low-end that your speakers cant actually reproduce without subwoofer help
Can you detect coupling caps in a blind test? Blind tests are the bane of bullshit audiophile myths.

I enjoy electronics but I usually don’t go by the audiophile book, because its usually full of bullshit and some of it can put my gear at risk.
I think removing caps from the audio path is more or less like changing a jellybean opamp for a audiophile one that can actually degrade your system performance because of oscillations.
I found about dc offset when I read about it on the original cmoy article, even if its a very important thing that can destroy a pair of expensive headphones the cmoy article only shows the caps because the original virtual ground goes batty when you plug Low-Z headphones.
My luck is that I usually do my homework before I go guns blazing in to a project even if its a simple one.
After doing some research on the layout of my ART Headamp 4 I noticed the dc filtering caps it has on all outputs. ART is a respectable studio equipment maker so this says a lot about their worry to protect expensive headphones, not like some audiophile companies or designers.

Some of you might say they don’t agree with me, to those I say this: Imagine you have really fast car but it could go just a bit faster if you removed all the safety devices, would you do it? If your answer is yes, you don’t love your gear and should see your loudspeakers or headphones blow up. I’m an evil one.

My DC coupling caps.

Solve for -3 db Frequency Solve for Capacitor Value
Load Input Impedance (Ohms): 32
Capacitor Value (µF): 680
-3db Frequency (Hz):7.31
Optimal low frequency response (Hz):73.14

After some “study” I went for the 680uf caps. 
32 Ohms are the base impedance of my grados.
People say electrolytics color the sound, I must be deaf because I don’t notice coloration.
 

9V dual rail cmoy.


My 9V dual rail cmoy with the Jan Meier Crossfeed (2 positions & bypass).
The plastic box is lined with aluminium tape and the perfboards rest on pcb cooper boards, it’s a fully modular project.
Opamp made by Burr-Brown (2132PA), I’m using the original ones still made by Burr-Brown if that stuff actually matters to some of ya.
Two AMB sigma25 9V boards in dual rail configuration and a simple power bank.

Audio jack by Neutrik, RCA jacks are gold plated or something like that, LEDs by Vishay and bad cable work by your friend here.
10x Gain it does have some noise using my test earbuds but I need to test it a little more. I wont show more photos of this thing.

I learned a lot from this little project and thats what matters most.

Sound is really good for such a project, I recommend doing it but without all the fancy crossfeed and dual rail supply, it sounds really good powered by a 9V and a TLE rail splitter.