Wilson's Audiophilics

[audiophilics]

[audiophilics]

Introducing Cel

Hi guys, it’s been another milestone since I’ve updated. Right now we have our first cmoy amplifiers almost ready for sale.

btw what do you think of our new cmoy case?

sound quality is as pristine as any renown cmoy amplifier. Packaging and how we present this product will be slightly different from the other cmoys out there as we intend to make this product more educational.

stay tuned for more updates! First 100 is being prepped in our kitchen as of now!

[audiophilics]

Sorry for the lack of updates. But I'd say there's been significant progress here for our first amplifier. It's gonna be a cmoy for sure. But it's gonna be a cmoy with a touch of a new design.

[audiophilics]

DSO Nano V3

Just got me a mini digital storage oscilloscope today. Gave it a spin and I would say it is good only for specific uses especially testing digital signals rather than analog signals. 

[audiophilics]

Throwback to my extremely messy desk while working on the cmoy headphone amps

[audiophilics]

A different taste of cmoy

I just received new parts today to build another cmoy with my remaining altoids tin box. 

However, this time I tried a different op amp. I used the OPA2227PA and came up with a comparison. 

AD823ANZ - sharp and vibrant, might cause ear fatigue

OPA2227PA - smooth and warm, will not cause ear fatigue as easily. 

Here’s a picture my new cmoy, and yes it finally comes with a knob

Here are some test results for this new cmoy I’ve built on yet another stripboard. 

So far results are nearly identical except at 20hz. I will be using this op amp mainly because it produces warm bass and thus it’s much nicer to listen to. 

Next up, perfecting the current design and maybe push for a rechargeable cmoy?? Stay tuned!

[audiophilics]

Here are some test results and pictures on my working cmoy

They actually look pretty promising as distortion stays below 0.01%. However, sound is a bit too clear and sharp making it rather tiresome to listen to. 

[audiophilics]

Finally a working CMoy prototype!

Hi guys, I apologise for not updating this blog for the past week. I've been busy at work but I finally got a chance to revisit my CMoy project.

After testing several railsplitter designs and using a stripboard to do my works, I finally got a working CMoy with the AD823ANZ. I will post some pictures on the amplifier and also some FFT test results later.

The only problem now is that the audio is too clear and sharp. Kinda like watching a 4k super amoled TV at night. It gets tiresome to capture the amount of detail similar to prolong listening to my CMoy amp. What I need is a warmer sound and so, I shall test the opa2132 op amp next..

[audiophilics]

Cmoy 3rd prototype

Hi guys, sorry I didnt get back to you previously as there were many complications in the cmoy amp. 

Many things have happened in the past week. Allow me to run you thru what I’ve accomplished and oh.. the amp is finally working! (well 90% working..) 

Bought a couple of altoids tin boxes. 

Turned it into an amp :D 

However.. the audio still distorts below 500Hz and when under load (high impedance headphones) 

I suspect it could be the railsplitter circuit as it is not supplying enough current to the circuit. Hopefully my next prototype would be able to address these issues. 

Here’s a picture of the amp on the outside, hope you like it!

[audiophilics]

Second prototype cmoy amplifier

Just received the PCB today from PCBgogo. Looks like my cmoy is slowly getting there. I was very excited to come back from work and start working on my cmoy today but I realised the layout for the jacks weren’t for the ones listed in the bill of materials I provided. :( Just sent an order for the new 3.5mm jacks, will update you guys again with test results when its done.

[audiophilics]

Audio measuring devices

Oscilloscopes are very useful tools for measuring audio signals passing thru specific components. Most oscilloscopes have a bandwidth much higher than that of what we require in an audio device (20hz to 20khz) thus, there are no difficulties finding the right one for you. 

A cheap portable oscilloscope that I’ve been interested in is the nano DSO V3

Although not as fully featured as a full desktop class oscilloscope, this oscilloscope has all the functions I need to do basic measurements on the amplifier circuit. Definitely do look it up! 

Another way of measuring is to get a USB sound card with wave output and a spectrum analysis software to go along with it.

An example of a really sexy interface is the dScope III.. 

This beast here costs about $13kSGD. However there are several other alternatives such as the spectraDAQ for a more home use scenario rather than for professional use. Note that these specialised sound cards are paired up with an FFT spectrum analysis software on your computer and they make analysis much more flexible as everything is done via software. 

In conclusion, definitely get a basic oscilloscope to measure signals for noise going thru specific components of a circuit. But ultimately, try investing on a soundcard + spectrum software as they are very flexible (as everything is processed via software) plus, the wave generator in these soundcards produce purer waves compared to those generated from your typical audio sources. Thus, eliminating any discrepancies in your data collection.  

[audiophilics]

Just learnt something interesting today. Ever wondered how those rock guitar sounds are produced? They are done thru clipping of the sound waves thru either a tube amp set at an amplification beyond its capacity or a solid state IC.

Is it possible to make a lower powered amp distort with a low powered tube amp? Or is an IC chip able to do the job?

[audiophilics]

Sound signature/ sound modification of an amplifier.

What are sound signatures of an audio device? Do such things really exist? Sound signatures only exist in the world of headphones, IEMs and speakers. They can either be 

1) Analytical - treble boosted, mids and bass recessed

2) Balanced - treble and bass boosted, mids recessed

3) Bassy - bass boosted, mids and treble recessed

4) Midrange-y - mids boosted, bass and treble recessed 

Unfortunately, no such headphones or IEMs could really drive all frequencies without any bias due to the design of its drivers. To achieve proper balance in an audio set up, one must have multiple speakers which drives different frequency ranges. For example, a subwoofer is used to drive lower frequencies whereas a tweeter is used to drive higher frequencies. 

So what do amps have to do with this? Contrary to popular beliefs, amps are supposed to be neutral as much as possible. Transparent in a way that it’s only supposed to amplify the audio with minimal distortion. However, it is possible to modify the sound by modifying the circuity. For example, adding some capacitors in the feedback loop will cause a bass boost or bass handling but might cause overall muddiness to the audio. I am currently researching on adding low pass/ high pass filters to an amplifier. Would it be more useful in a guitar or portable headphone amplifier? 

Also, do tube amplifiers really change the sound signature of audio such that its warmer and smoother? 

[audiophilics]

Throwback to my first CMoy amplifier done on breadboard. This amplifier is my first and noisiest amplifier I've ever built (because of the number of jumper cables crossing over each other creative EMI interferences). I plan to make a better one and test its true capabilities as an amp. This time though, I'll be using an AD823ANZ op amp done on a proper PCB.

[audiophilics]

Introduction

Hi everyone, my name is Wilson, I am an audiophile. Well sorta.. I just love music very much that I sometimes try to produce music whereas other times I try to find ways to hear music the way it’s meant to be heard (right in front of the performer). I started this blog because recently, my head has been blowing with ideas on reproducing songs especially on the technical side.. and I would love to spread my inspirations as well as gather more feedback on my ideas from amplifiers to headphones to midi instruments (things audiophiles love). Feel free to go technical on me as I would love to dig deep into the op amps, resistors, capacitors, etc.. 

To end off.. here’s a really really nice picture of a glowing tube amp.