Showing posts with label amplifier. Show all posts
Showing posts with label amplifier. Show all posts

This Week I Learned 2018 - Week 33

Last post or some random posts from the archive.

Do you need standups? Maybe you don't. (via HN) Some comments in HN resonate with me based on the experience of the implementation. Maybe is just me, but it does feels like cargo cult software engineering. Team culture, business culture, or management issue? Execution of the practice is still al lot to be desired. Interesting development days ahead.

What are Thonet & Vander speakers like? The sad case in MY here is that there is no way for us to purchase any good budget speakers. The funny thing is that this particular brand Thonet & Vander is readily available. Some local distributor have brought this in (why that particular distributor did no brought HiVi Swan to MY?). Nevertheless, as the comment suggestion, this is one of those OEM manufacturer which use European brand names to implies good quality. Back to the question, is this brand of speaker good enough? My personal opinion, mostly are multimedia speakers (something you bought for your kids) and Amazon's reviews didn't justify anyone to fork money on it (there are other brands exists in similar market, Edifier). Unless we have good review from NO Audiophiliethis comment shares my sentiment.

Which "budget" stereo amplifier to get? It's between Onkyo A-9010 and Marantz PM5005. Price wise both are the same and it's just the sound signature. For A-9010, I'm not sure that I need to replace the Samwah capacitor to Nichicon gold tune capacitor. However, different country have different version. However, I'm not sure the model sold here is EU (digital inputs and normal capacitors) or UK (better capacitors, no digital input, and Wolfson WM8718 DAC) version. Having digital input is good if you want to hook up to Chomecase Audio via Toslink input. Also, the loudness button (which increases sounds at low volume, good for classical music like BolĂ©ro) piqued my interest with the device.

Why not stick to amplifier like SMSL SA50 which is cheaper? Those class D amplifier is truly budget amplifier which missing quite a lot of features compare to amplifier like A-9010, a class AB amplifier. Furthermore, the output rating have been inflated. Class D amplifier should be sufficient enough for a small room.

Speaker wise. Just pair it up with a floor standing speaker if you don't want to invest a sub-woofer. The speaker's bass should be sufficient enough.

Encountered this error "Odd number of elements in anonymous hash..." and took me a while to figure out what went wrong with the the code. It turned out that Perl's hash will accept single element Hash without a key-value pair. Hence, the warning. I was surprised that this is not a syntax error. The example code below. See if you can identify the issue. Hint, the `foobar`. There is a good explanation at Stack Overflow on this warning message. Turn on warnings people!
my $result = $api->GetSomething({name => {'foobar'}});

This Week I Learned - 2017 Week 40

Last week post or the usual archive stuff.

Week 40. Twelve more weeks to go before the end of the year.


The case against open office when people just copy without including the subtle details of the design and layout. While many organization sugarcoat the many benefits of of open office layout, the main advantage is the organization save a significant money using such layout.





200 productive hours per month? (via HN) Research shown that it's possible on daily basis, if a worker can concentrate 4 hours on deep work and remaining 4 hours on shallow work (meetings, random discussions, surfing, and slacking off). However, deep work requires more solitary environment, which is not possible in a open office environment.


Via Reddit. You always have to be suck at something before you can be better at it as shown in the quote below. But, unless you're constantly improving, you will stuck at the expert beginner level.
"Successful writers are people who allow themselves the freedom to suck—unrepentantly, happily, even."

What are the best combination (budget and feature wise) to setup a desktop music system? Below are the list of components:

(1) JBL LSR305 active speaker
(2) Lexicon Alpha audio interface / Behringer UCA222 / HIFIME(DIY) DAC
(3) XLR-to-3.5mm cable / TRS-to-3.5 mm cable / XLR male to RCA male cables

You should look into the issue of balanced audio.


Slashdot is 20 years olds! Ironically, good discussion was found in HN instead! I found the site when it was going through it second year and getting more popular due to discussion of FOSS. And off course, those idiotic memes, Anonymous Cowards, and BOredAtWork comments. Man I feel so old.


Audio gd is an interesting audio equipment manufacturer. The website still looks like those site Geocities era and you have to wait for a while for your order to be processed and built. While relatively unknown in some part of the world, Audio gd is one of those China manufacturers who build good audio equipment or parts.


How to increase gain in FX-Audio DAC X6. Some Redditor found a tiny little hack that increases the overall gain of the amplifier.

This Week I Learned - 2017 Week 39

Last week post or the old archive.


Picking up lots of audio related stuff. Interesting week indeed.

Building a audio system but worry that your spending will lead to a serious discussion with your significant other(s)? Pay an acceptable amount on your credit cards and the remaining amount by cash. The audio sales person suggested this "workaround" for all his client who worry about their spending being known to their significant other(s). Interesting indeed. On self-reflection, if you worry your spending will cause an issue with your significant others(s), then you should not even spend that amount of money.


Buying headphone but low on budget? Doesn't have a trained ears or the time to test through all available headphones? Get Superlux HD668B, definitely worth every cent of your money!

One interesting trend with audio shop in MY is the emerging of community oriented stores. Currently, Starpickers and E1 Personal Audio are the two good example of such type of stores. Chill environment and good place for local audiophile meetup.


Klipsch R-15PM powered speaker (also known as active speaker). Worth it? Not with a retail price of MYR 2600. Unless you have extra cash to burn, have (going to build) a vinyl records collection, and love a minimum setup (no need extra amplifier, receiver, or DAC) with different input sources (TV, PC, Bluetooth, and Phono). Suitable for neat freaks who like clean setup where you have a pairs of speakers which can connect to to any electronic devices that generate sounds. Furthermore, JBL LSR 305 is still a better choice, sound and money wise (you can get it from Massdrop around MYR 1500 inclusive of shipping).


Stoner Acoustics UD125 is a locally made DAC and headphone amplifier. Price is set around USD 85 or MYR330. While I'm tempted to get it and support our locally made product, is it worth the money?

As I learned by reading blog posts and watching videos on different DACs and amplifiers, the product is as good as the components. While there is no information on what brands of capacitor used, the key electronic components are (1) Savitech SA9037 USB Audio Processor. The audio chip. I can't find any information on this except there is another audio chip using model number SA9027. (2) Asashi Kasei Microdevices (AKM) AK4490 High Performance DAC. (3) Texas Instruments (TI) TPA6120A Dual Channel High Power Amplifier.


When comes to reviewing and modding the Nobsound MS-10D Tube Power Amplifier, this guy knowledge sharing and follow ups is simply epic. We need more producer rather than moocher in this world.


Why you shouldn't spend money on cheap amplifiers or DACs. Be careful SMSL stuff as it's notorious known for creating spark when plugged in. Just get Lexicon Alpha and JBL LSR305s.

This Week I Learned - 2017 Week 38

The usual stuff or last week post.

Long weekend holidays. More rest and clean up.


Fluff in Scientific Writing by Celia M. Elliott (PDF). Right, I definitely write in a fluff way. Awareness is the first step to improve your own writing.


So you have a pair of passive speaker. What now? The next step is to get a DAC and an amplifier. Or you can get a Class-T amplifier with build-in USB DAC and headphone amplifier combo like Topping TP30-MARK2. The USB DAC let the amplifier serves as an external sound card so you can channel out the sound from your PC through the USB.

As I learned in the last week post, the quality of any amplifier is the whole sum of its electronic components, especially the amplifier chip and capacitors. Screenshot below illustrates the PCB board and its components. Unfortunately, the amplifier chip is Tripath TA2024, which push about 15 watts per channel, a bit lacking for bookshelf speakers.



SMSL SA-36A PRO, while it's a affordable and quality amplifier, has two different versions. To save cost, the manufacturer have switch the amplifier chip from Texas Instrument TPA3118D2DAP to STMicroelectronics TDA7492PE. The general consensus from the reviews and forum discussions recommended to get the TPA3118 version. Maybe the SMSL get a better pricing from STMicroelectornics or Texas Instrument cannot keep up with the demands. This also reminded me of certain manufacturer which produced quality and affordable first generation of said product to get good rave reviews and slowly replace with cheaper components for next generation.

Unfortunately, SMSL SA-50 is currently out of stock and I can't find it in the SMSL website. Maybe SMSL decided to phase it out from the market? What about SMSL SA-60? It's not shown in the official website as well.


Neurochome's LM3886 done right? The correct amplifier design compare to others like Circuit Basics or Electronics Lab. I believed Tom Christiansen's experiences at Texas Instrument allows him to design the most optimized audio amplifier using TI LM3886 amplifier chip.


YouTuber FFcossag channel is what I consider good review, teardown, and educational on a particular amplifier. Good example was how he evaluated through the specification of Breeze Audio TPA3116 as shown below. Even better, his videos are in public domain! While we need to absorb and digest large unknown information, his does provides a quantitative (objective) rather than qualitative (subjective) analysis of an amplifier. Sometimes, it sounds nice to the reviewer is a personal taste.



While we're on Breeze Audio. Be extra careful when you plug in the power supply. One reviewer, NFM popped and burned one of the capacitor while testing it. Luckily he was protected by the aluminum case. Be extra careful with all these low end amplifier, supply lower power to the amplifier or you switch the capacitors to a higher voltages type. It does raises quite a lot of safely concerns with all these low cost amplifiers (no quality control, cheap or cloned electronic components) from China.




FFcossag also provides another excellent objective review on popular Lepai LP-2020A+. See video below. While the amplifier is way under-power compare to what the manufacturer claimed in the spec sheet, it's still value for performance worthy amplifier. However, the same problem exists. You can't bloody get this amplifier in MY and have to try your luck sourcing it from China.



Similarly, he also trashed the Lvpin LP-838 and make the consumer aware of what are they getting of buying a cheap amplifier. To save cost, certain manufacturer will reuse or recycle certain components. Is it safe? Hard to tell but it certainly does not increases any confident (more on this later) in using the product. Be an informed buyer, buy from reputable dealer and brands.


This Week I Learned - 2017 Week 37

The old stuff or last week post?

Slow week but things are moving ahead. More focus and getting more deep work done.


Familiar name that caught my attention while watching the game demo. Glad to see him living his dream and doing what he love. He is part of the team (Ninja Theory) that developed Hellblade: Senua's Sacrifice (watch the development diariesIGN's review, or GamePlayHK's broadcast) is worth checking out. I've wondered, what if I'm more persistent and follow his path?





The Search for Better Search at Reddit. Every initial search implementation starts with default Database's own internal natural language full-text search implementation. For PostgreSQL is Tsearch2 and MySQL is FULLTEXT index.


Different publications have different writing style guides. If you're going to publish to their journals, follow their convention.


When comes to affordable (ahem, cheap) amplifier, Lepai is a well-known brand and the general most people would recommended it as your first amplifier. However, there was confusion about another brand, Lepy or Lvpin, which was initially thought as a clone but actually is the same company but a new name. To differentiate this, Lepai brand is used in US or internationally by Part Express and Lepy brand is used in China or TaoBao. Different name confused and influenced my search effort as I was searching for the wrong brand name. Nevertheless, if you searching for Lepai amplifier in MY, search for "Lepy" keyboard instead.

Even though these are cheap amplifier, the audio amplifier chip (more on this later) and quality of the capacitors will determine the overall sound output and pricing. Some audio enthusiasts with good electronic knowledge will purchase this category of amplifier and upgrade or modify it with better parts.




Tripath TA2020 is interesting audio amplifier chip. IEEE ranked it as one of the microchip that shock the world as it allows consumer grade sound systems to produce higher sound at a lower price. It even created a new amplifier category, Class-T amplifier, which is a proprietary variant of Class-D amplifier.

Entry level amplifier typically based their design on these few variants of Class-D/Class-T amp chips.

(1) Tripath TA2020A/TA2020A+ (20 watt per channel), TA2021, TA2024(15 watt per channel).
(2) Texas Instruments TPA3118 (30 watt per channel).
(3) STMicroelectronics TDA7492PE (45 watt per channel).

Discussion on different audio amplifier brings no benefit if you're not a audiophile or trained ears to notice the subtle differences. For a beginner, start with the cheapest possible amplifier available at your place.