Cilynx' Projects

AWS Database Matrix

Fri, 27 May 2022 03:50:18 +0000

	RDS	Aurora	Redshift
MySQL	Native	Compatible, 5x Native Throughput
MariaDB	Native
PostgreSQL	Native	Compatible, 3x Native Throughput	Based on
Oracle	Native
SQL Server	Native
Workload	OLTP	OLTP	OLAP
Availability	Multi-AZ, Automatic host replacement	Multi-AZ and Multi-Region cluster options	Clustered by default. Multi-AZ and Multi-Region options
Durability	Automatic backups with point-in-time recovery. Manual snapshots.	Multi-AZ cluster volume, Automatic backups with point-in-time recovery, manual clones	Automatic data node replacement (Cluster is unavailable for queries while replacing a data node.)
Consistency	Read-after-write on source. Read replica lag as per each native engine.	Read-after-write on primary. Milliseconds on in-region replicas. Seconds on cross-region replicas.	Transactional consistency on producer and consumer clusters.
Partitioning	Native sharding	MySQL tablespaces, PostgreSQL partitions	Supported only in Spectrum
Elasticity	Relatively straightforward vertical and horizontal scaling. Can run Reserved Instances or On Demand	As RDS or has a serverless offering that automatically starts, scales, and stops infrastructure as necessary, but has some limitations.	More complex to resize leveraging elastic resize, classic resize, snapshot, restore, and resize or automated concurrency scaling.
Storage Size Limit	64 TiB (MySQL, MariaDB, PostgreSQL, Oracle), 16 TiB (SQL Server)	128 TiB	Petabytes (directly), Exabytes (Spectrum / S3)
Table Size Limit		64 TiB (MySQL), 32 TiB (PostgreSQL)

Technics SU-8044 SKT-0039 Replacement

Thu, 27 Aug 2020 19:04:44 +0000

Kurzweil K1000 Diagnostic Mode

Mon, 24 Aug 2020 03:21:02 +0000

Getting into Diagnostic Mode
Navigation
Menu Tree

Getting into Diagnostic Mode

Start with your K1000 turned off
Hold down C and Play/Edit while turning the power on
You can release C and Play/Edit once Kurzweil K1000 Test Supervisor appears on the LCD

7 and 8 navigate up and down the menu options
9 resets the currently displayed item to its default value
3 actions the currently displayed item – use it to drill into menus, call up reports, and execute tests
4 goes back / up
5 and 6 increment and decrement numeric parameters

RUN ALL TESTS
RUN SELF TESTS
RUN LCD TEST
RUN BUTTON TEST
RUN MIDI TEST
RUN SINE WAVE T
RUN BATTERY TST
TEST SEL MENU
CONFIGURE MENU
ERROR STATS
EXIT SUPERVISOR

SIG ANALYSIS
LOOP ON ERROR
DISP ERR TEXT
DISP ERR DATA
DISP BAD BITS
SCOPE LOOP
ERR MESS FAST
ERR MESS SLOW
ERR MESS HOLD
MAIN MENU
TEST SEL MENU

LCD VISUAL TEST
BUTTON TEST
PROGRAM ROM TST
SETUP ROM TEST
RAM TEST
BATTERY BAK TST
TIMER TEST
UART TEST
ARNOLD 1 TEST
ARNOLD 0 TEST
SOUND ROM TEST
ONE SAMPLE TEST
MIDI LOOP TEST
SINE WAVE TEST
SEVEN SAMP TEST
LCD SCOPE TEST
MAIN MENU
CONFIGURE MENU

Kurzweil K1000 Power Supply

Fri, 21 Aug 2020 14:56:17 +0000

Battery
Capacitors
Diodes
Fuses
Headers
Integrated Circuits
Resistors
Transistors

Battery

ID	Type	+	-	Function
B1	BR-2/3A 3V	R9(B)	Digital Ground	Configuration Memory Backup

Capacitors

ID	Type	+	-	Function
C1	22000uF Electrolytic	+8V Unregulated	Digital Ground	Smooth Input to +5V Regulator
C2	F104Z 25V Ceramic parallel with C1	+8V Unregulated	Digital Ground	Smooth Input to +5V Regulator
C3	10uF 16V	+5V Rail	Digital Ground	Smooth Output from +5V Regulator
C4	F104Z 25V Ceramic parallel with C3	+5V Rail	Digital Ground	Smooth Output from +5V Regulator
C5	2200uF 25V	+15V Unregulated	Analog Ground	Smooth Input to +12V Regulator
C6	F104Z 25V Ceramic parallel with C5	+15V Unregulated	Analog Ground	Smooth Input to +12V Regulator
C7	10uF 16V	+12V Rail	Analog Ground	Smooth Output from +12V Regulator
C8	F104Z 25V Ceramic parallel with C7	+12V Rail	Analog Ground	Smooth Output from +12V Regulator
C9	2200uF 25V	Analog Ground	-15V Unregulated	Smooth Input to -12V Regulator
C10	F104Z 25V Ceramic parallel with C9	Analog Ground	-15V Unregulated	Smooth Input to -12V Regulator
C11	10uF 16V	Analog Ground	-12V Rail	Smooth Output from -12V Regulator
C12	F104Z 25V Ceramic parallel with C11	Analog Ground	-12V Rail	Smooth Output from -12V Regulator
C13	10uF 16V	R11(A)	Digital Ground	Smooth R11 Input to Buffer Network
C14	F104Z 25V Ceramic	+5V Rail at U1(14)	Digital Ground	Smooth +5V Input to Buffer Network

Diodes

ID	Type	K	A	Function
D1	C4P03Q	K1:J1(1), K2:J1(3)	+8V Unregulated	+5V Rectifier
D2	Black, T85 8-B	+15V Unregulated	J1(4)	+12V Rectifier
D3	Black, T85 8-B	+15V Unregulated	J1(6)	+12V Rectifier
D4	Black, T85 8-B	J1(6)	-15V Unregulated	-12V Rectifier
D5	Black, T85 8-B	J1(4)	-15V Unregulated	-12V Rectifier
D6	Orange Glass, Yellow Stripe	R1(B), R2(B), R7(B)	D7(A)
D7	Red Glass, Black Stripe, 6B	+8V Unregulated	D6(A)
D8	Orange Glass, Yellow Stripe	D9(K), Q4(C)	+5V Rail
D9	Clear Glass, Red Stripe	D8(K), Q4(C)	R9(A)

Fuses

ID	Type	Function
F1	5A 125V Fuse	Protect +5V Rail
F2	500mA 125V Fuse	Protect +12V Rail
F3	500mA 125V Fuse	Protect -12V Rail

Headers

ID	Type	Function
J1	6-Pin Molex KK-396	AC Input from Transformer
J2	10-Pin Molex KK-396	Connection to CPU Board
J4	13-Pin Molex KK-254	Connection to Audio Board

J1 Pin	Function
1	8 Vac (0-deg)
2	Digital Ground
3	8 Vac (180-deg)
4	15 Vac (0-deg)
5	Analog Ground
6	15 Vac (180-deg)

J2 Pin(s)	J4 Pin(s)	Function
1	1	Backup Battery
2	2	Power OK
3	3	Reset
4,5	4,5	Digital Ground
6,7	6,7	+5V
8	8,9	+12V
9	10,11	Analog Ground
10	12,13	-12V

Integrated Circuits

ID	Type	Function
U1	74HCU04	Hex Inverter used as buffer array
U2	3052V	+5V Regulator
U3	7812	+12V Regulator
U4	7912	-12V Regulator

+5V Regulator (3052V)

Pin	Connection
Input	+8V Unregulated
Output	+5V Rail
Ground	Digital Ground

+12V Regulator (7812)

Pin	Connection
Input	+15V Unregulated
Output	+12V Rail
Ground	Analog Ground

-12V Regulator (7912)

Pin	Connection
Input	-15V Unregulated
Output	-12V Rail
Ground	Analog Ground

Hex Inverter / Buffer Array (74HCU04)

The hex inverter is used as a buffer array with a voltage divider (R5 & R6) providing hysteresis to avoid flapping the reset signal as the analog voltage input comes online.

You can find a good explanation of the concept on StackExchange.

Only five of the six inverters are used. Pins 12 & 13 are not part of the buffer array.

Pin	Connection	Function	Hypothetical Value
U1(1)	C13(+), R11(A)	Input for Pin 2 (1A)	1 (System Input)
U1(2)	R5(B)	Invert Pin 1 (1Y)	0 (Invert P1)
U1(3)	R6(B), R5(T)	Input for Pin 4 (2A)	0 (Same as P2 through R5)
U1(4)	Pin 5	Invert Pin 3 (2Y)	1 (Invert P3)
U1(5)	Pin 4	Input for Pin 6 (3A)	1 (Same as P4)
U1(6)	Pin 11, R6(T)	Invert Pin 5 (3Y)	0 (Invert P5, Same as P3 through R6)
U1(7)	Digital Ground	GND
U1(8)	Reset Signal Output	Invert Pin 9 (4Y)	0 (Invert P9, System Output)
U1(9)	Pin 10	Input for Pin 8 (4A)	1 (Same as P10)
U1(10)	Pin 9	Invert Pin 11 (5Y)	1 (Invert P11)
U1(11)	Pin 6, R6(T)	Input for Pin 10 (5A)	0 (Same as P6, Same as P3 through R6)
U1(12)	[None]	Invert Pin 13 (6Y)
U1(13)	+5V Rail	Input for Pin 12 (6A)
U1(14)	+5V Rail	Vcc

Resistors

ID	A	B	Function
R1	Digital Ground	R2(B), R7(B), D6(K)
R2	Q1(B)	R1(B), R7(B), D6(K)
R3	Q1(C), Q2(B)	+8V Unregulated, D7(K)
R4	R11(B), Q2(C)	+5V Rail
R5			Voltage Divider to add hysteresis to buffer network
R6			Voltage Divider to add hysteresis to buffer network
R7	Q3(B)	R1(B), R2(B), D6(K)
R8	Q3(C)	Q4(B)
R9	D9(A)	B1(+)
R10	Analog Ground	Digital Ground
R11	C13(+), U1(1)	R4(A), Q2(C)

Transistors

ID	Type	B	C	E
Q1	C1815 NPN	R2(A)	R3(A),Q2(B)	Digital Ground
Q2	C1815 NPN	R3(A),Q1(C)	R4(A),R11(B)	Digital Ground
Q3	C1815 NPN	R7(A)	R8(A), Power OK Signal	Digital Ground
Q4	A1015 PNP	R8(B)	D8(K), D9(K)	+5V Rail

Technics SU-8044 Troubleshooting Test Points

Thu, 13 Aug 2020 01:13:45 +0000

Transistor Parameters

Comp	PN	Bt	Ct	Et	Ba	Ca	Ea
Q101	2SA722MS	0	-19.5	0.55	0.0	-19.3	0.5
Q102	2SA722MS	0	-19.5	0.55	0.01	-19.3	0.5
Q103	2SC1815	-19.5	-2.0	-20.1	-19.3	-2.8	-20.0
Q104	2SC1815	-19.5	-2.0	-20.1	-19.4	-3.1	-20.0
Q105	2SC1815	-2.0	23.2	-2.6	-2.8	22.7	-3.4
Q106	2SC1815	-2.0	23.2	-2.6	-3.0	22.8	-3.6
Q403	2SC828	-37.8	-37.3	-38.5	-35.5	-35.0	-36.1
Q404	2SC808	-37.8	-37.3	-38.5	-35.2	-34.6	-35.9
Q407	2SC1815	-37.3	-5.2	-38.0	-35.0	-5.6	-35.6
Q408	2SC1815	-37.3	-5.2	-38.0	-34.6	-6.2	-36.2
Q409	2SC1885	-38.0	-1.3	-38.6	-35.6	-1.2	-36.1
Q410	2SC1885	-38.0	-1.3	-38.6	-35.3	-9.9	-36.0
Q411	2SA564	10	0.6	10.6	10.0	0.6	10.7
Q412	2SA564	10	0.6	10.6	10.0	0.6	10.7
Q501	2SC1913
Q502	2SA684NC
Q503		31.1	39.4	30.5	28.4	37.2	27.7
Q504		0	32.2	0	-0.9	29.5	0

Dual Transistor Parameters

Comp	PN	Bt	Ct	Et	Ct	Bt	Ba	Ca	Ea	Ca	Ba
Q401	2SA798A	0	-37.3	0.6	-37.8	0	0	-35.2	0.6	-35.6	0
Q402	2SA798A	0	-37.3	0.6	-37.8	0	0	-35.1	0.6	-35.7	0

IC Parameters

Comp	PN	1t	2t	4t	5t	6t	7t	8t	9t	0t	1a	2a	3a	8a	9a	0a
IC201	NJM4559DS	0	0	-16.4	0	0	0	17.2
IC401	SVISTK0039N	-1.3	-39.6					0	39.4	1.2	-1.3	-37.2	0	0	36.9	1.2
IC402	SVISTK0039N	-1.3	-39.6					0	39.4	1.2	-9.9	-37.2	0	0	37.0	-7.3

Component Physical Locations

T	ST	ST	F	I	I	I
	Q504	Q503		Q502
		IC401		IC402
Q604	Q603	HS	HS	HS
	Q605	HS	HS	HS	Q106	Q105
	Q601	Q409	Q412	Q410	Q104	Q103
		Q407	Q411	Q408	Q102	Q101
Q602		Q403	Q401	Q402	Q404

Component Schematic Locations

Title
Q101	Q103	Q105	Q412	Q411
Q102	Q104	Q106	Q401						Q601
			Q403	Q407	Q409			Q603
			Q402				Q605	Q604
			Q404	Q408	Q410				Q602
						Q503
						Q504

Jelly Comb Webcam Comparison

Sun, 19 Jul 2020 22:11:54 +0000

	WGSXT-002(H602) WGSXTYQJY002-20-05-31	WGBG-006(H606) WGSXTYQJ003-20-05-31	C101 WGSXTYQJY004-20-06-01

USB ID	1bcf:28c4 Sunplus Innovation Technology Inc. 1080P Webcam	1bcf:28c4 Sunplus Innovation Technology Inc. FHD Camera Microphone	1bcf:28c4 Sunplus Innovation Technology Inc. FHD Camera Microphone
Focus	Manual	Automatic	Automatic
MJPEG (Motion-JPEG, compressed)	1920x1080 @ 25 fps 1280x1024 @ 25 fps 1280x720 @ 25 fps 1024x768 @ 25 fps 800x600 @ 25 fps 640x480 @ 25 fps 320x240 @ 25 fps 160x120 @ 25 fps	1920x1080 @ 30 fps 1600x896 @ 30 fps 1280x720 @ 30 fps 1024x576 @ 30 fps 800x600 @ 30 fps 800x480 @ 30 fps 640x480 @ 30 fps 640x360 @ 30 fps 424x240 @ 30 fps 352x288 @ 30 fps	1920x1080 @ 30 fps 1600x896 @ 30 fps 1280x720 @ 30 fps 1024x576 @ 30 fps 800x600 @ 30 fps 800x480 @ 30 fps 640x480 @ 30 fps 640x360 @ 30 fps 424x240 @ 30 fps 352x288 @ 30 fps
YUYV (YUYV 4:2:2)	1920x1080 @ 5 fps 1280x1024 @ 5 fps 1280x720 @ 10 fps 1024x768 @ 10 fps 800x600 @ 10 fps 640x480 @ 25 fps 320x240 @ 25 fps 160x120 @ 25 fps	1920x1080 @ 5 fps 1600x896 @ 7.5 fps 1280x720 @ 10 fps 1024x576 @10 fps 800x600 @ 15 fps 800x480 @ 25 fps 640x480 @ 30 fps 640x360 @ 30 fps 424x240 @ 30 fps 352x288 @ 30 fps	1920x1080 @ 5 fps 1600x896 @ 7.5 fps 1280x720 @ 10 fps 1024x576 @10 fps 800x600 @ 15 fps 800x480 @ 25 fps 640x480 @ 30 fps 640x360 @ 30 fps 424x240 @ 30 fps 352x288 @ 30 fps

Supported video formats are as reported by v4l2-ctl --list-formats-ext. The default mode is highlighted in bold.

Lepy LP-2020A Teardown & Testing

Fri, 10 Jul 2020 14:46:15 +0000

It doesn’t take long to realize that this amp is nowhere near as good as its namesake. To start off with, the product description includes such gems as “Class D is better than Class T”….which is patently impossible considering Class-T is a subset of Class-D.

The 2020A at 100% volume both on the input signal and the amp is just loud enough to be uncomfortable with the HPMs, but even at that volume the sound doesn’t “fill” a 15’x15’ room. It sounds thin, far away, fake. The real Tripath drives the HPMs to fill the room with rich sound at comfortable listening levels and even at background levels you can talk over. For raw power, the real Tripath amps get well into “hearing protection required” territory well before maxing out either the input signal or amp volume. It’s like the difference between sitting right in front of the band in a small venue (the real Tripath) or being in the parking lot outside a concert hall (this thing).

Looking under the hood, it’s a completely different board than its namesake. The main chip is a Yamaha YDA138 that has been rebadged as LP2020-A 1501. They even went as far as putting Lepy branded covers over the output filter inductors.

Googling around, some folks claim that the Yamaha chip used here actually does a good job if you setup its supporting circuitry correctly. If I ever care enough in the future maybe I’ll play with swapping components, but for the moment, I’m going with the idea that the amp should perform well as shipped.

1% THD @ 40Hz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
12V	1.2A	14.4W	71dB	7.96V
13V	1.3A	16.9W	73dB	8.70V
14V	1.4A	19.6W	75dB	9.33V

1% THD @ 1kHz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
12V	0.64A	7.68W	107dB	7.93V
13V	0.60A	7.80W	108dB	7.94V
14V	0.58A	8.12W	107dB	7.94V

Specifications

Brand	Model	Chipset	Avaliability	Included Power Supply
Lepy	LP-2020A	YDA138 (rebadged as LP2020-A 1501)	~$35 on Amazon, but seriously, get something else	BK-40W-13.5Us1130905 12V/3A

Lepy LP-2024A+ Teardown & Testing

Thu, 09 Jul 2020 14:46:15 +0000

Considering the model number, I expected this one would have a Tripath TA2024, but it turns to have a TAA2008. Overall, the performance is just barely below the Lepai LP-2020A+, but honestly it’s within the margin of error.

1% THD @ 40Hz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
12V	1.15A	13.80W	70.0dB	6.92V
13V	1.22A	15.86W	70.3dB	7.51V
14V	1.30A	18.20W	71.0dB	8.07V

1% THD @ 1kHz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
12V	0.73A	8.76W	109dB	7.81V
13V	0.79A	10.27W	110dB	8.37V
14V	0.85A	11.90W	109dB	9.91V

Specifications

Brand	Model	Chipset	Avaliability	Claimed Input Power
Lepy	LP-2024A+	Tripath TAA2008	No longer available	DC12V3A

Lepy LP-2051 Teardown & Testing

Tue, 07 Jul 2020 14:32:59 +0000

If you’re looking for the most powerful of the Tripath mini-amps, this is it. With the LX-22s, it puts out a full 15dB more volume at 1% THD than the original Lepai LP-2020A+ and even puts the newer Kinter K2020A+ and Lepai LP-2020TI to shame.

The only “downside” is that the powersupply is basically a laptop brick. That said, if you’re looking for quality amplification, you’ll likely see that as a good thing. =)

1% THD @ 40Hz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
19V	2.00A	38.00W	85.8dB	13.40V
18V	1.84A	33.12W	84.0dB	12.65V
17V	1.75A	29.75W	82.0dB	11.89V

1% THD @ 1kHz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
19V	1.17A	22.23W	116dB	13.40V
18V	1.12A	20.16W	115dB	12.75V
17V	1.07A	18.19W	114dB	12.08V

Specifications

Brand	Model	Chipset	Avaliability	Input Power
Lepy	LP-2051	Tripath TK2051	~$40 on Amazon	DC19V3A

Lepai LP-2020TI Teardown & Testing

Mon, 06 Jul 2020 15:23:37 +0000

Parts-Express claims this one is the “one true successor” to the original Lepai LP-2020A+. They say that they designed this amp around the Texas Instruments TPA3118 because the Tripath TA2020 has become hard for them to source. Further, they claim the new 2020TI sounds “cleaner” and is more powerful than the original 2020A+ with the 2020TI putting out 14W@1%THD as compared to 7W@1%THD for the 2020A+ when running on the same 12V@3A (36W) power supply.

To my ear, however, this new offering is inferior to its predecessor. First off, the TI amp appears to be less efficient. You have to turn it up higher to get the same volume and maximum output on the TI is lower than from the Tripath. Second, at the risk of sounding like an audiophile knob, the TI seems to convey less presence and soul.

This amp doesn’t sound bad, but to about the same degree that the Kinter K2020A+ sounds better than the Lepai LP-2020A+, this one sounds worse. Considering this is the most expensive of the amps on my list, I don’t see any reason for anyone else to buy one as long as the Kinter K2020A+ and Lvpin LP-2020A+ are available.

1% THD @ 40Hz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
12V	1.19A	14.28W	73.0dB	8.27V
13V	1.26A	16.38W	73.4dB	8.75V
14V	1.37A	19.18W	75.7dB	9.44V

1% THD @ 1kHz, JBL LX-22 Speakers

Input Voltage	Input Current	Input Power	Volume	Output Voltage
12V	0.64A	7.68W	112dB	8.19V
13V	0.70A	9.10W	112dB	8.88V
14V	0.76A	10.64W	113dB	9.70V

Specifications

Brand	Lepai
Model	LP-2020TI
Manual	LP-2020TI Operating Manual
Amplifier Chip	Texas Instruments TPA3118
Availability	~$40 on Amazon
Face Text	Lepai^® Stereo Digital Audio Amplifier
Board Text	SM1520 2015/11/11 V1.1
Right Channel	Bottom Red Jack
Left Channel	Top White Jack
Input Power Label	DC12V3A
Included Power Supply	TH201505 12V/3A

Cilynx' Projects

AWS Database Matrix

Technics SU-8044 SKT-0039 Replacement

Kurzweil K1000 Diagnostic Mode

Getting into Diagnostic Mode

Navigation

Menu Tree

MAIN MENU

CONFIGURE MENU

TEST SEL MENU

Kurzweil K1000 Power Supply

Battery

Capacitors

Diodes

Fuses

Headers

Integrated Circuits

+5V Regulator (3052V)

+12V Regulator (7812)

-12V Regulator (7912)

Hex Inverter / Buffer Array (74HCU04)

Resistors

Transistors

Technics SU-8044 Troubleshooting Test Points

Transistor Parameters

Dual Transistor Parameters

IC Parameters

Component Physical Locations

Component Schematic Locations

Jelly Comb Webcam Comparison

Lepy LP-2020A Teardown & Testing

1% THD @ 40Hz, JBL LX-22 Speakers

1% THD @ 1kHz, JBL LX-22 Speakers

Specifications

Lepy LP-2024A+ Teardown & Testing

1% THD @ 40Hz, JBL LX-22 Speakers

1% THD @ 1kHz, JBL LX-22 Speakers

Specifications

Lepy LP-2051 Teardown & Testing

1% THD @ 40Hz, JBL LX-22 Speakers

1% THD @ 1kHz, JBL LX-22 Speakers

Specifications

Lepai LP-2020TI Teardown & Testing

1% THD @ 40Hz, JBL LX-22 Speakers

1% THD @ 1kHz, JBL LX-22 Speakers

Specifications