Lowyat.NET: Latest topics by chchyong89

Making a most straight forward Class A amplifier!

chchyong89 — Mon, 02 Nov 2020 23:07:50 +0800

Its been many many years I have no activities in this forum after being packed by a superb heavy work load as a electronics device designers in a PA company that making tons of Class D amplifiers...

"unfortunately", I managed to spare myself some free times during this unlucky MCO to work on a Class A biased power amplifier that I have always wanted to build loonnggg loonggg time ago for my beloved Leema Xero. After thousand sips with the wine that I have bought just for this long MCO, here are some philosophies & goals for the designs:

1. The layout must built as clean & straight forward as possible. Laying PCB layout needs 20% Skills, 80% Arts!
2. Left & Right must be done symmetrically.
3. Arranging Power signal and small signal stage in orders.
4. Minimizing the wiring is a must, there must be no flying wires from AC socket to the board, no flying wire to the RCA Jack, no flying wire to the banana jack, and no flying wire to the bridge rectifiers, so no one can argue that changing the internal wires in the amplifiers to silver/gold/platinum/titanium/millennium wires can make the amp sound better!
5. Everything must be done on ONE PCB. Not because of cost saving, squeezing everything into one PCB is a very challenging job!
6. It must be done on a solid piece of aluminum heatsink that can occupy 2 channels, to make entire things look even more straight forward inside out.
7. Run in Dual Mono configurations, Left & Right must be electrical isolated. Ground loops happen everywhere, especially when you are using RCA wires!
8. NO "audiophiles grade" components! This amplifier must SOUND GOOD even without using the expensive audiophiles components.
9. The driving power must be enough for a 1000sf Condo usage.
9. A ~1~1.5Vdc offset protection is a must. Nobody can guarantee that airplane wont crash into your toilet some day right?

1. Helping DIPTRACE to advertise their super easy to use PCB drawing software here~ #diptrace

2. This is a 2 layers, 2mm, 1oz PCB. The luckiest things is I still can buy and ship thing from china.
However the shipping fees is rather slow and more expensive than usual.

3. Started with the most joyful parts, soldering. The only moment that I can stay quiet and focus.

4. Here's the chassis parts, guess what? this is an I-BEAM that meant for construction/machining use! To be honest I have been browsing internet for more than a month before came to this decision. Why I have chosen it? Because it looks really simple and it has the weight and surface to hold the heats.

5. Aluminum FEET, I know we audiophiles like this thing!

to be continue...........

[WTS] Medical CEM DT-8806H Non-contact Thermometer

chchyong89 — Wed, 15 Apr 2020 23:20:22 +0800

Item(s):

Brand new Medical FDA/CE Certified CEM DT-8806H Non-Contact Forehead

Package includes:

Infrared Thermometer Gun
User Manual
Mini Screw Driver
2 x 1.5V "AA" Battery

Price: RM249
Warranty: 1week

Dealing method: COD

Location: KL

Contact method/details: PM
---

Item(s) conditions: New

Picture:

[WTS] CEM DT-8806H Non-contact Thermometer

chchyong89 — Wed, 25 Mar 2020 19:53:18 +0800

Item(s):

Brand new Medical FDA/CE Certified CEM DT-8806H Non-Contact Forehead

Package includes:

Infrared Thermometer Gun
User Manual
Mini Screw Driver
2 x 1.5V "AA" Battery

Price: SOLD
Warranty: 1week

Dealing method: COD

Location: KL

Contact method/details: PM
---

Item(s) conditions: New

Picture:

[WTS/Bulk] Aperion Audio Verus iii Floorstanding

chchyong89 — Sat, 17 Nov 2018 23:54:24 +0800

Aperion Audio is one of the underrated Brand in hifi and AV industrial. It caught my attention early this year in Hong Kong, the sound is phenomenal! I am Looking for more friends who are able to join the group buy with me to make this order success. The market price at US is @ USD2,498/pair.

Item(s): Aperion Audio Verus iii Grand Tower

Package includes: New in BOX

Price:
MOQ
3 Pair - RM8,900/pair
6 Pair - RM8,500/pair
9 Pair - RM8,000/pair

Group Buy kakis:
1. Me
2.
3.
4.
5.
6.
7.
8.
9.

Warranty:
1 Year by me

Dealing method:
COD

Location:
Setapak

Contact method/details:
Ol72O7773l whatssap
---

Item(s) conditions:
Brand New

Reason for sale:
Group buy

Not convincing about the product? Here are a list of reviews that I hope it helps :

http://www.ravepubs.com/listen-aperion-aud...grand-speakers/
https://www.soundandvision.com/content/aper...r-system-review
https://www.avnirvana.com/threads/aperion-a...ker-review.819/
https://www.digitaltrends.com/speaker-revie...erus-ii-review/

Looking for Company (Johor)

chchyong89 — Fri, 30 Sep 2016 21:16:23 +0800

Hi Programmers Kalian,

I am looking for a company who can deliver embedded programming services (STM8S, STM32, MSP430 etc ) in Johor. Payment will be project based and long term co-operation is definitely more desirable.

Any recommendation?

The EGD & EGA Review & Loan Program

chchyong89 — Mon, 07 Dec 2015 10:24:59 +0800

[center][/center]

The fully balanced EGD & EGA Loan Program is now available in the Peninsular Malaysia. Thanks to Penmarker who raised up this suggestion.

How this program works:

Members who wish to participate in the program must have a minimum 500 cumulative posts with good feedback in the forum. I'll compile a list of the members who wish to participate in this post. When the member receives the DAC & Amplifier, they will need to post a confirmation that they received them. After their test period, they'll get the address for the next person on the list, and pay for the shipping. Each member will have 1 week to test the DAC/AMP and at the end of their test period, they'll send them on to the next person on the list. For now, this program is only available in Peninsular Malaysia.

The guidelines:

1. Reply in the thread if you wish to join this program, list down the gears you will be using.
2. Write your impressions in this thread, a paragraph or so would be sufficient.
3. Do not modify or unscrew the device.
4. Keep the amp for no more than 10 days for testing purposes.
5. Ship it to the next person with Skynet(recommended) or Poslaju.

Products info:

www.stoneracoustics.com/EGD
www.stoneracoustics.com/EGA

Review:
1. I can live if I can only have EGD as my only DAC, the neutrality, balanced and purity is what EGD set the benchmark and earn my respect here...
2. The Stoner Acoustics EGA is a steal, especially if you already have a full balanced DAC and headphone to pair with...
3. It had injected life into an otherwise old and obsolete pair of cans...

Loan Program List:

1. Penmarker
2. sonerin
3. yen262
4. yimingwuzere
5. noobandroid
6.
7.

A Little Benches for your Reference

chchyong89 — Fri, 30 Oct 2015 18:18:22 +0800

First of everything, this post has to give a big credit to E1 Personal Audio, I managed to capture some measurements comfortably at E1 today, it's really a comfort place to test your favorite audio gears without feeling stress

Before going further, here is a disclaimer. There will be no confliction of the tested devices with my products at all because the tested devices are in Single Ended, while all of my products are in Balanced input and output. The measurement device (QA400) has it's limitation, so you may take the loop back test result as your reference.

Settings:
-Using 2 separated battery powered laptop to avoid ground loop.
-All DACs was set to 24/96khz
-All output set to around -3.5dBFS for better accuracy reading.
-Captured with No load and 33ohm static load.
-Skirt is wide... I have no idea

First, loop back test, let see how well this device can goes.

[WTS] Cheap D3200 + Sigma 50mm

chchyong89 — Mon, 13 Apr 2015 12:31:07 +0800

Item(s):

1. Red Nikon D3200
2. Free 18-55mm Kit lens (sizz noise when focusing)
3. Sigma 50mm DG HSM F1.4 with HOYA Pro1 Digital 77mm
4. Sandisk Extreme 16GB
5. Warranty no more
6. shuttle count 11xxx

Price:
RM1600 sapu all Firm.

Warranty:
1 week personal.

Dealing method:
COD Selangor, Negeri Sembilan, Melacca

Contact method/details:
PM
---

Item(s) conditions:
Working Perfectly.
Shuttle 11xxx

[WTS] High Fidelity Full Range Passive Bookshelf

chchyong89 — Thu, 09 Oct 2014 10:44:00 +0800

[center]

[/center]

Item: OEM High fidelity 4-inch full range bookshelf passive speaker.

Color : High Gross White/Black/Red

Rated : 89dB/4ohm

Price : RM499 (Skynet @ Peninsular)

Warranty : 1 Year

https://www.facebook.com/StonerAcoustics

Audition is available at my humble private working room @ Mahsan, Bahau, N.S.

COD is available at Puchong/Shah Alam/PJ. Appointment needed.

[WTS] UD120 32Bit 384kHz Audiophile DAC

chchyong89 — Sun, 07 Sep 2014 11:24:08 +0800

[center][/center]

https://www.facebook.com/StonerAcoustics

QUOTE

Back to 2012, we launched our UD100 at USD49, a bare DAC module with yellow heat-shrink. People simply like it because of it's simplicity, and it sounds surprisingly sweet. But audiophile always thirst for better. We received tons of suggestions everyday. They told us they need higher resolution, they need more bit depth. At 2013, we put up something at the same price, with higher playback resolution - UD110. But this just doesn't end their thirst of desires. They told us they need a DAC that capable to support ALL ranges of playback resolution. They told us they need a proper case. They told us they need a better option than connecting the mini-jack on the PCB. Email by email, thought by thought, these suggestions make the born of UD120.

Item(s): UD120 @ 32/384(asio)

Driver: Click Here

Package includes: DAC

Price: ~~RM199 + RM10 Poslaju~~ RM149 + RM10 Poslaju

Warranty: 1 Year

Dealing method: Postage

Contact method/details: PM

For more detail, please visit to our Facebook page and Blogspot Page.

[WTS] UD100 USB DAC ( PCM2706 + ES9023 )

chchyong89 — Tue, 15 Jul 2014 21:09:23 +0800

Item(s):
UD100 USB DAC (this comes with LP5907)

Package includes:
DAC without heatshrink

Price:
RM100 inclusive poslaju

Warranty:
3months

Contact method/details:
PM

Age of item:
New

Picture:

Reason for sale:
Extra units from OEM batch for customers. Limited units.

[WTS] Used Desktop PC Selling Cheap!

chchyong89 — Wed, 09 Jul 2014 20:13:17 +0800

Item(s):

i5-2500
MINIX-H67-USB3 (One Sata port malfunction)
2 x 4GB Mushkin PC3-10700
AMD FirePro V4900
Corsair VS450
Crucial M4 128G
Dell U2311H (Display Port) (Bought second hand from forumer)
Lian Li PC-Q7 (Dusty with some minor scratch)

All Items lost track of age. Boxes and Warranty cards is not available anymore.

Personal warranty 1 week.

Price RM1xxx COD Puncak Jalil.

[WTS] Moving out sales

chchyong89 — Sat, 28 Jun 2014 16:57:00 +0800

Dear All, I am having moving out sale at ridiculous price. But in a condition that, you have to take all together in one shot, and no tutorial provided, you must have an idea how to use these all. No warranty provided for components. The rest all 1 week full refund warranty.

This is best for those who are interested in electronics hobby.

All together = RM2600, come and pick up. @ Puncak Jalil. No negotiation, the price is unbeatable.

NJM4556AL SIP-8 x 4 RM1
C-media CM6631 x 9 (No datasheet provided) RM50
PM39LV512-70VCE x 4 RM1
LT3032EDE-12 x 2 RM5
LT3032EDE-5 x 4 RM10
ESS ES9018 No datasheet provided) x 1 RM50
P-DUKE PDL02-05D15 (used) RM2
MURATA MTU1D0509 x 1 RM10
OPA1632 SOIC-8 x 10 RM20
OPA1632 MSOP-8 x 10 RM20
LME49724 SOIC-8 x 3 RM6
IR4312MTRPBF x 5 RM50
TPS7A3001DGNR x 11 RM11
TPS7A4901DGNR x 11 RM11
ISO7220M x 4 RM4
LT1762EMS8-5 x 10 RM20
AD1896AYRSZ x 20 RM30
LME49990MA/NOPB SOIC-8 x 380 RM600
LP5907UVE3.3NOPB 2 reels. 250unit/reel each, (you need a serious microscope and skill to solder, used some units) RM100
AK4396VF x 20 RM50
ADUM4160BRWZ x 50 RM150
ADUM5000ARWZ x 50 RM150
BINGZI M50-05B 2x21V/25VA x 2 RM50
PCM5102 x 10 RM10
Mini USB SMT x 90 RM10
1 messy packing of resistors, small capacitors(too much values, 1/4W, 3W etc) RM2
NOVER 15000uF/35VDC x 8 RM20
Rubycon CE 70V4700uF(M) x 3 RM5
DAEWOO refurbrished 2200uF 100wv x 24 RM25
Few different size new Perfboard RM1
65mm Transparent heatshrink 1meter RM1

ADUM5000 Module (Used) RM10
Gold platted RCA 1 pair RM5
Neutrik NC3MAAH-1 x 10 RM20
BLM18PG471SN1D 4kreel, Used half reel, RM10

PCB design by dvb-projekt
Tube-I-zator SRPP Stage for I-Out DAC V2.0 11/2010 x 1
Shunt Regulator for TDA1541 DAC 01/2010 V1.0 x 1
TDA1541A NOS DAC Board Design by dvb-projekt 05/2010 V2.3 x 2
Ultra High Speed Buffer by dvb-projekt(with 3x NC7SZ125) x 1
Shunt Regulator for TDA1541 DAC Circuit design by SALAS PCB Layout by SALAS 01/2010 V1.0
RM250

TEAM TSD32048M1066C7-E 2GB DDRIII1066Mhz CL7-7-7-21 (Used) RM10
NANYA NT1GT64U8HB0BN-3C 1GB PC2-5300S-555-12-F1.667 (Used) RM10
Intel I3-2310M (Used) RM20
J-LINK USB x 1 (Used) RM10
USB DIGITAL Microscope with driver (Used) RM5
Profibus cable, mini to mini cable, DVI to DVI cable, Power Cord RM1
AC Adapter 19V/3.42A x 1 (Used) RM5

AMTECH RMA-223 x 1 Used 10% RM1
AMTECH NC-559-ASM-UV x 1 Used 10% RM1
MECHANIC XG-Z40 x 2 Used 10% RM2
Massive Heatsink 29*20*5 Used, drilled with many holes and scratches. x 2pcs RM20

SMT/BGA used 3 zones infrared reflow machine Used RM300
101-0AS Dry Box baker RM300

1 Pair OEM High Gross piano Paint Passive Bookshelf Speaker 4inch 1inchTweeter (some scratch here and there) RM300

[WTS] UD110v2 USB DAC, For Audiophiles.

chchyong89 — Tue, 08 Oct 2013 14:17:05 +0800

[center]
Good News, the new UD110v2 works on the android devices(UAC1) and *Raspberry NOW!

16bits/48khz @ Quantasylum QA400

32bits/96khz @ Quantasylum QA400 (limitation of measuring device)

16/44.1khz Jtest

16/44.1khz original Jtest.wav FFT

Versus the UD100

16bits/48khz @ Quantasylum QA400[/center]

UD110 is a High Performance, Ultra Miniature and definitely a Non-Hyped DAC that built for the real audiophiles at an unbelievable price.

The Built:
RECEIVER : SA9027
LDO : LP5907
CLOCK: AK8133E
DAC : PCM5102A
OUTPUT : 2Vrms @ 10kohm
RESOLUTION : 16/32bit @ 32/44.1/48/88.2/96Khz
SUPPORT : ~~WINDOWS 32/64 with driver~~ , windows 32/64, ubuntu, ,MAC OS, androids(UAC1), Rasp(*w/o Volume controls) with native driver.
*For windows OS that is older than windows 8, 32-bits need to be enabled by using audio streaming protocol like ASIO or wasapi.

PRICE : 160 inclusive Poslaju
WARRANTY : 1 year 1-to-1

An USB ESS sabre DAC

chchyong89 — Wed, 01 Aug 2012 23:42:01 +0800

[center][/center]

Finally, a much higher end DAC released, with much lower price and much smaller size! Have no time to post the detail of it until today due to busy working hours. The design goals were built by optimizing the layout to maximize the performance of the DAC while maintaining tiniest possible size.

The selling price was squeezed to lowest possible by introducing lowest possible parts count of SMDs and avoided the use of unnecessary expensive and meaningless electrolytic capacitors, either in signal or power paths. With the integration of negative charge pump in the DAC, there are no capacitors throughout the signal paths that will colorize the sound characteristics to retain purest possible audio signals transmission. Throw away the need of high or low frequency filtering stage on signals path ensuring full signals transmitting. Shortest signals travelling, reducing EMI throughout the DAC. And finally, introducing with direct connectivity to your USB slot without additional USB cable greatly reduced the messiness of cables on your tables.

The premium point is that the DAC is using ESS sabre ES9023, which can outperform most of the commercial DACs at a certain value. My words on this product is, don't judge the performance of this DAC base on the size and the selling price that will biasing your final conclusions.

[center][/center]

I have named this as UD100 as the first product under my newly registered trading company. And I have added a logo on my PCB to protect myself from the same incident happen again.

A simple review from my friend, click

[WTS] ESS SABRE ES9023 Audiophile USB DAC

chchyong89 — Tue, 31 Jul 2012 00:49:19 +0800

[center]

[/center]

This is an USB DAC based on ESS Sabre ES9023 Chip that built for real audiophiles, who demand for smallest size possible. Neglected so call audiophile grade capacitors and resistors, but the performance still remained top notch at this price range. There will be no other product that can come close to this at the price and size. Unlike other products that built with discrete components or luxury parts, and few of them even used up high end chips, this simple DAC can perform equally or even better compare with other commercial DACs due to it's superior layout finishing. And i named this as UD100 for the first product on my newly registered trading company, Stoner Acoustics (002118419T). The selling price will be only RM140, please believe this. Any question regarding this DAC can drop me a PM and leave this thread as trading purpose. Like our page for more photos.

Product : UD100

Price : RM140 with heatshrink wrapped + RM10.West/RM12.East (Postage)

Warranty : 6 months T&C applied.

First 100 UD100 owners :

» Click to show Spoiler - click again to hide... «

Next 100 UD100's owners :

» Click to show Spoiler - click again to hide... «

Another 100 UD100's owners :

» Click to show Spoiler - click again to hide... «

301. Daniel Yarde UK RR142397869MY
302. CHONG PENG US RR142397909MY
303. wansirpunk EM122590103MY
304. pduff_06 EM122590117MY
305. ttan98 AUS RR142397841MY
306. Daniil Chubiy Ukraine RR142397872MY
307. Ken Tam Singapore RR142397824MY
308. lipfvng EM122590324MY
309. Bryan Chow Singapore RR142400007MY
310. mistralmudd EM122590315MY
311. hypermount EM122590307MY
312. Ng Brian Hongkong RR139281083MY
313. Florio Alagna Italy RR139281049MY
314. Tam Bo Wen Singapore RR139281070MY
315. Akihiro Gion Japan RR139281097MY
316. Morten Brandt Denmark RR139281035MY
317. Richard Aylard United Kingdom RR139281052MY
318-319. Jesper Nilsson Sweden RR139281066MY
320-323. alamakazam Singapore RR139281106MY
324. JOHN DAVIS United States RR142397736MY
325. Gleibys Buchanan United States RR144192806MY
326. Dead_longkang EM122590284MY
327. Paul McCormick UK RR144192749MY
328. Raul Reinson Estonia RR144192797MY
329. Vincent Teunissen Netherlands RR144192752MY
330. Cedric Koh Singapore RR144192766MY
331. Ryan Bishop Australia RR144192783MY
332. Ahmad Nazri EM122590125MY
333. TurboJetZ EM122590298MY
334. KAMIZATO Takeshi Japan RR144192770MY
335. lonelystarz EM122590275MY
336. Arjan Geven Austria RR144492160MY
337. boogiemk4 EM122590134MY
338. Peh Shing Bo Singapore RR144492142MY
339-340. ABU NOR AZMAN Singapore RR144492156MY
341. vyonxhin EM122590267MY
342. Joao Silva portugal [/color] RR144645325MY
343. Aaron Murphy Australia RR144645736MY
344. Viet Nguyen Norway RR144645740MY
345. 高江遊 Japan RR144645753MY
346. TeddyZai EM122590253MY
347. cswe EM122590240MY
348. bebebhadzir EM122590148MY
349. mastermindsos EM122590151MY
350-351. Morten Denmark RR144492085MY

------------ OUT OF STOCK--------------
//Thread will remained open until end of this month for any inquiry.

352. Lonestrider EM122590165MY
353-354. ShinnKQ EM122590179MY

Updating...

i7 2720QM ES on my G470

chchyong89 — Tue, 26 Apr 2011 00:49:35 +0800

8MB cache i7-2720QM engineering sample

» Click to show Spoiler - click again to hide... «

It's easy to change the processor without voiding the warranty.

RM1499+600.. It's quite worth btw.

ak4396 dac open public

chchyong89 — Sun, 03 Apr 2011 05:03:16 +0800

Due to my reputation is going down hill and i can't find myself an evidence on it, so all i could only do is to admit that i am dishonest to make somebody happy.

For this DAC, no point for me to continue develop and market it as i thought before. Here i open it public that the dac i wished to sell in the earlier time, you may continue to develop the DAC by taking this for your reference as education purpose and build yourself a unit to play around. *Be noted that everything is still on draft, no working proof atm. The final product will be totally carry no commercial mean. It using pcm2707 as usb receiver and ak4396 as DAC. There is no second ak4396 with i2s input schematic on the internet, so find me one and claim that i copy it if you could. To make "some" of you simple, click here.

Datasheet
http://www.asahi-kasei.co.jp/akm/en/produc...ak4396_f00e.pdf

(Datasheet as reference)Pins to take note:
*P/S-25: H for Parallel mode, Internal pulled-up, so can be ignored.
*ACKS-28: Pull H for auto setting mode
*DFS0 : Ignored, but must tide to DVSS/DVDD
*De-emphasis mode : Off in this designed
*IIS mode by setting: DIF0=1, DIF1=1, DIF2=0
*Pins 15: Grounded to cmos mode in this design

The LPF filter, it can be done by using OPA1612, opa2365 etc tat USB capable to power up.

For ARC circuit that done likely on DACPORT, an upsampler can be add as below.

Inner of DAC port

chchyong89 — Tue, 29 Mar 2011 12:03:18 +0800

Source from http://www.earzone.com.tw/viewtopic.php?p=...997449fd1cf04fe

USB receiver: Unknown
SRC: AD1896
DAC: AK4396
Output stage: OPA1612
Headphone amplifier: TPA6120

USB isolator for your USB DAC

chchyong89 — Wed, 09 Mar 2011 23:48:56 +0800

To beg for cleaner Power feed to the DAC, here is a little trick i use
which it make more sense compare with changing stupid pure
silver or pure cold cables.

Effect? Very subjective, what i going to say is, it's very good!

Oh ya, this isolator work on all USB DAC!

reference:
http://www.circuitsathome.com/measurements/usb-isolator
http://diyparadise.com/shop/index.php?main...products_id=124
http://www.diyaudio.com/forums/digital-lin...solation-5.html