Electronics Lab Philippines

SKA GB150D

Offline Tukkar

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Re: SKA GB150D
« Reply #480 on: January 16, 2015, 04:20:09 PM »
Sorting my things out and found my 2 boards of this GB150 board from sir Tony....ano na balita sa mga gumawa nito...

Gusto ko ng i populate yung board at ng masubukan kasi nuon ang dami pa palang revision...meron na bang fully working amp?
People who don't like capacitors, are they Purists o Foolish?....

Offline JLesterP

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Re: SKA GB150D
« Reply #481 on: March 23, 2015, 06:25:58 PM »
Malapit nang tumunog itong sa akin  :D
All parts locally sourced except sa output resistors.
 



Class-D module and Amplifier kits
http://bit.ly/JLElectronicsPh

Offline Tukkar

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Re: SKA GB150D
« Reply #482 on: March 25, 2015, 03:45:21 PM »
nice one....
People who don't like capacitors, are they Purists o Foolish?....

Offline kirk simone

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Re: SKA GB150D
« Reply #483 on: April 20, 2015, 09:20:23 PM »
waiting mode at baka makasali sa 2nd batch ng groupbuy
shake it .....

Offline DJyoung

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Re: SKA GB150D
« Reply #484 on: April 24, 2015, 10:52:56 AM »
post naman video para may ebidensiya din

Offline JLesterP

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Re: SKA GB150D
« Reply #485 on: September 08, 2015, 11:33:29 PM »
temp sensor mounting


mosfet mounting
brass standoffs should be 8mm high


Will take scope measurements pag may permanent case na :)
I'm getting 29V RMS output at 8 ohms load using 2 pairs output mosfets

Sample Vid
https://youtu.be/vpFfnZmgKRU
Class-D module and Amplifier kits
http://bit.ly/JLElectronicsPh

Offline JLesterP

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Re: SKA GB150D
« Reply #486 on: September 09, 2015, 12:10:11 AM »
Schematics (final and tested)
Source resistors are increased to 0.33ohms so that we can use unmatched output mosfets.
I have to replace D4 to 6.2V zener, because the negative output clips earlier when loaded at 4 ohms (zener acts as limiter), issue occurs because of source resistor's increased value.
R14 reduced to 1ohm to avoid oscillation/motorboating issues when using higher values.



Class-D module and Amplifier kits
http://bit.ly/JLElectronicsPh

Offline tony

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Re: SKA GB150D
« Reply #487 on: September 09, 2015, 06:45:31 AM »
nice one jlester....
now if we replace the fuses with say 47 ohm resistors instead and
then connect the sources to output trannies in parallel, then we have a high powered amp....

post here more often and when you have done 1000 posts, then
you can become a technical people...... ;)
* you simulate a circuit because you know how it works and wants to tweak, not because you want to learn how that circuit works....simulations do not teach you to be circuit smart...it comes with experience....
*http://www.diyaudio.com/forums/power-supplies/191730-tonys-latest-traffo-diy-build-15.html#post4375385
*do not judge any amp by its schematics, drawing lang yon, look instead at the finished amp, it tells a lot about the amp and its builder.....
http://ronelex.com/bias-current-output-transistor-amplifier/156

Offline Tukkar

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Re: SKA GB150D
« Reply #488 on: September 10, 2015, 09:12:55 AM »
good news para maumpisahan ko na rin yung board ko...
People who don't like capacitors, are they Purists o Foolish?....

Offline Abe T

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Re: SKA GB150D
« Reply #489 on: September 10, 2015, 11:32:32 AM »
Nice work, Les!  :)
I have no special talents, I am only passionately curious
Albert Einstein

...agree 100%. Throw your ideas at the wall, and see what actually sticks, as one person put it!
-Gnobuddy

Offline pEN DoTA

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Re: SKA GB150D
« Reply #490 on: November 28, 2015, 06:22:30 AM »
Ang ganda at ang linis ng tunog
Plus 1 sir les
GOD LOVES YOU

Offline tony

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Re: SKA GB150D
« Reply #491 on: November 28, 2015, 07:45:39 AM »
Ang ganda at ang linis ng tunog
Plus 1 sir les

+1 ka rin...ilang mA ang output bias mo per trannie?
* you simulate a circuit because you know how it works and wants to tweak, not because you want to learn how that circuit works....simulations do not teach you to be circuit smart...it comes with experience....
*http://www.diyaudio.com/forums/power-supplies/191730-tonys-latest-traffo-diy-build-15.html#post4375385
*do not judge any amp by its schematics, drawing lang yon, look instead at the finished amp, it tells a lot about the amp and its builder.....
http://ronelex.com/bias-current-output-transistor-amplifier/156

Re: SKA GB150D
« Reply #492 on: June 30, 2016, 05:27:52 PM »
Na-delete yung thread nito sa pinoydvd?

may nirereturn yung google search (site:pinoydvd.com Simple killer) pero wala na yung sa pinoydvd mismo? :(


Offline Ron_wrong

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Re: SKA GB150D
« Reply #493 on: July 01, 2016, 11:54:21 AM »
namana na pala ni Rochie yung ganito ko, hehehe

biased @10ma
30vdc
I am a DBA.

Offline JLesterP

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Re: SKA GB150D
« Reply #494 on: November 10, 2016, 06:17:50 PM »
Here's the THD measurements of my GB150D module. Pasok sa specifications ni Greg ball.  8) 8) 8)

I'm using QA400, a soundcard based audio analyzer by quantasylum. But it only accept voltages up to 4Vpp so I created my own interface using THAT1206 balanced receiver, THAT1646 balanced output and baxandall attenuator for fine tuning the signal going to QA400. My interface can accept up to 78Vrms signal and can protect the QA400 in case of DUT meltdown. The parts for the development of interface board costed me around 8K pesos (or higher) for the materials, so I should have bought the QA401 instead ;D

Voltage rails +/- 54V DC using Abletec SMPS.
For low output power, the harmonics looks good. At 50W to 100W, odd harmonics dominated the even harmonics. We'll see if it translates to "harsher" sound at loud volumes on listening test.

The setup




1W 8R load


5W 8R load


10W 8R load


50W 8R load


100W 8R load
Class-D module and Amplifier kits
http://bit.ly/JLElectronicsPh

Re: SKA GB150D
« Reply #495 on: January 03, 2017, 11:26:13 AM »
Lester, nakita mo yung post ni Terry dati na nakaka-cause daw ng iscillation yung ground lift resistor? Itry kong ijumper pag nabuo ko yung new board galing sa iyo.



I-offboard ko rin yung fuse. Sana gumana hehehe.

Offline JLesterP

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Re: SKA GB150D
« Reply #496 on: August 28, 2019, 06:44:38 PM »
Hindi ko nakita pero nung nag measure ako ng THD naka bypass yung ground lift resistor, measurements were cleaner if ground lift was bypassed.

Lester, nakita mo yung post ni Terry dati na nakaka-cause daw ng iscillation yung ground lift resistor? Itry kong ijumper pag nabuo ko yung new board galing sa iyo.



I-offboard ko rin yung fuse. Sana gumana hehehe.
Class-D module and Amplifier kits
http://bit.ly/JLElectronicsPh