Looking at my blog statistics I noticed some visits on my now old and very dead Cmoy project. Out of respect for the people who are visiting I wanna give an update on my electronics projects. Since I built that Cmoy headphone amplifier and crossfeed my life changed quite a bit, I don't have the … Continue reading Cmoy headphone amp update.
A fair review on the Beyerdynamic A20 headphone amplifier! I don't often reblog articles on my blog but this one is so well written that I'll share it. Hey! I'm a Beyerdynamic fanboy, so I'm biased! 🙂
So I bought a new CD player on Thomann, its a cheap Swissonic but for the money it’s pretty impressive. Massive bonus is the fact it has XLR outputs. I’ll be sincere I wont use half of the pro specs it has. It’s a pretty solid piece of gear for the price, the fact its … Continue reading Some updates on my gear.
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 … Continue reading The hero of DIY audio, Pow Chu Moy.
I have a deep respect for the NwAVGuy work on the O2 amplifier and like so many other enthusiasts around the audio circle I wonder what happened to him, so I really wish he is well and happy. There are some theories behind his disappearance. NwAVGuy’s death or the death of someone near him, got a job on … Continue reading The NwAVGuy mystery.
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€ … Continue reading JRC4556, shipment prices and other rants.
Don’t get me wrong I love to build stuff but I draw my limit on selling clones, one thing is to sell a Cmoy amp the other is selling a RA-1 clone and actually using the Grado name to do it. I know that people need to make money but stealing a layout and making … Continue reading Not Selling DIY Grado RA-1 clones.
I need to revise my cmoy headphone amp because that DC offset still bugs me a lot. I want to know what I did wrong or at least reduce the offset to an acceptable voltage 20mv to 25mv max. After some light reading my conclusion is that the problem can be from: A bad ground plane, a bad … Continue reading Revision to my headphone amplifier.
Half of the simple shielding I’ll do in the amp case and the Jan Meier Crossfeed.
Cmoy board using a darn Burr-Brown 2132PA. The JRC’s that I got need at least 9V in each rail to work fine…darn. Next crossfeed section from Jan Meier. I really need to shield these boards.
The DC regulator and rail splitter boards in the headphone amp enclosure. 12VDC to a 9V 7809 regulator to a dual TLE2426 rail splitter that outputs 4.2V to the V+ & V- rails. I flipped the RCA and power back panel after taking this photo, now the PWR jack is closer to the PWR switch. … Continue reading Headphone amp update.
Still need to make the led holes.
Headphone amplifier in the works. Not sure if I’ll use 9V batteries or a regulated source, maybe both. Believe or not that’s a lot of money on a table.
Image: Wikimedia.org What does Burr-Brown, JRC and Grado have in common? The Grado RA1 headphone amplifier, beautiful enclosure and sound until someone discovered that it uses a JRC 4556 opamp in a circuit similar with the popular Cmoy. Fanboys went nuts…an expensive headphone amplifier that uses a cheap opamp!? No way! We shall upgrade it to … Continue reading JRC 4556 opamp.