Apex A40 Amplifier Build Thread

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H

HatlessChimp

Member
Joined 2016
This is a dedicated thread to the Apex A40 Amplifier. Feel free to share your build and discuss and share information about the A40.
I will do my best to keep this 1st post updated with as much information as possible. I am still building this out, please be patient. If there are any errors please let me know! :)

The Project
The Apex A40 Amplifier was designed by Apex Audio and kindly shared to DiyAudio community. He has continually shared various designs, revisions and countless feedback over many years. All of his designs are popular and well endorsed by many experienced members in the DIYA Community. The original thread can be found here - 100W Ultimate Fidelity Amplifier - diyAudio

Schematic

Apex A40 Files
Gerbers, Mirrored PCB images, Photos, Schematic and Partial .txt BOM can be gound here - https://www.diyaudio.com/forums/solid-state/338942-apex-a40-amplifier-build-thread.html#post5817489

a40%20pcb%20color.jpg

Bill of materials
Anyone with an up to date BOM for Digikey please contact me

Transistor Choices
2SA1943 – Toshiba, On Semiconductor - Transistors - Bipolar (BJT) - Single | Discrete Semiconductor Products | DigiKey
2SC5200 – Toshiba, On Semiconductor - Transistors - Bipolar (BJT) - Single | Discrete Semiconductor Products | DigiKey
MJL4281 - On Semiconductor - Transistors - Bipolar (BJT) - Single | Discrete Semiconductor Products | DigiKey
MJL4302 - On Semiconductor - Transistors - Bipolar (BJT) - Single | Discrete Semiconductor Products | DigiKey
NJW0281GOS-ND - On Semiconductor - https://www.digikey.in/products/en?keywords=NJW0281
NJW0302GOS-ND - On Semiconductor - https://www.digikey.in/products/en?keywords=NJW0302

Are my transistors a fake/copy thread - My Transistors, original or copy?

Power supplies

Construction tips
Please contact me with any tips you have to share.

Project modifications
Know of any proven mods? Please share them!


Recommended DIY Pre Amp
Apex P30

A40 Members and build photos
Please Share your builds!

JUST WAITING ON MODERATOR APPROVAL FOR UPLOADING MORE FILES TO THIS THREAD/POST.

Cheers!
 
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H

HatlessChimp

Member
Joined 2016
APEX A40 FILES
Includes - Gerbers, Mirror PDF, Schematic, Top view.


APEX PROTECT FILES
Includes - Silkscreen, Mirror PDF, Sprint File.
 

Attachments

  • APEX STEREO PROTECT FILES.zip
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  • APEX A40 By ALEX MM rev1.4.jpg
    APEX A40 By ALEX MM rev1.4.jpg
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  • APEX A40 PCB GERBERS By ALEX MM rev 1.4.zip
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  • APEX A40 CFA BOTTOM MIRRORED By ALEX MM rev1.4.pdf
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  • APEX A40 CFA ALL CRAY RED BLACK TOP VIEW By ALEX MM rev1.4.pdf
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  • 138 APEX A40 CFA By ALEX MM rev1.4.txt
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H

HatlessChimp

Member
Joined 2016
More APEX A40 FILES
These files I've listed as Version B only to help all the files from getting mixed up. :)
 

Attachments

  • A40 CFA APEX ALL GREY rev1.4 (Version B).pdf
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  • A40 CFA APEX BOTTOM MIRRORED rev1.4 (Version B).pdf
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  • A40 CFA APEX TOP SILK SCREEN MIRRORED rev1.4 (Version B).pdf
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  • APEX A40 SCHEMATIC From Directory of Apex Audio Thread.JPG
    APEX A40 SCHEMATIC From Directory of Apex Audio Thread.JPG
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  • A40 CFA APEX Colour TOP rev1.4 (Version B).jpg
    A40 CFA APEX Colour TOP rev1.4 (Version B).jpg
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  • A40 CFA APEX Colour BOTTOM rev1.4 (Version B).jpg
    A40 CFA APEX Colour BOTTOM rev1.4 (Version B).jpg
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  • A40 CFA APEX Colour TOP PCB rev1.4 (Version B).jpg
    A40 CFA APEX Colour TOP PCB rev1.4 (Version B).jpg
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H

HatlessChimp

Member
Joined 2016
UNCONFIRMED A40 FILES
These files I am unsure if they are usable. Would be nice if someone could please help me verify them and provide some information on them. Thanks! :)
 

Attachments

  • A40 CFA APEX ALL rev1.6 (UNCONFIRMED).pdf
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  • APEX A40 LIFTED GROUND (UNCONFIRMED).jpg
    APEX A40 LIFTED GROUND (UNCONFIRMED).jpg
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  • A40 Sprint File (UNCONFIRMED) .zip
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alex mm

alex mm

Member
Joined 2006
A40 in progres

Hi all,
The latest revision of PCB :D Will be ready this summer . :D
BR Alex
 

Attachments

  • DSC04490-001.jpg
    DSC04490-001.jpg
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  • DSC04491-001.jpg
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  • DSC04492-001.jpg
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  • IMG_20180829_175409.jpg
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Reactions: 1 user
B

burnmaster

Member
Joined 2016
Hi shahzad831. Hope you know what I'm saying because I'm using an online translator. Which I changed into my future A40 and I hope it is good. To double the power I build 2 monoblocks, each block having 2 bridge boards. I use on powerful transistor terminals. I raised the current in the 800mA final resistors ... you probably call it a bias. The end transistors are very expensive, so I use big radiators. Extremely strong I have emphasized on the capacities, as I am convinced that they bring the good sound.)) For each monoblock are provided 250,000mF. For the whole amplifier 500,000mF .... or in short, half Farad.) Previous tests passed successfully. The good thing in this case is that every monoblock due to the bridging connection will use XLR connectivity, and also my oppo sonica dac has a fully balanced XLR output.

I hope I've been helpful. Greetings.
 
S

shahzad831

Member
Joined 2016
Thanks for feedback guys. Actually i have some numbers of orignal sankens in stock ao i want to utilize them in a40 or sr200 . Issue is this, that i have an SMPS (based on 2110 3525 ETD 59 DIY) whos output is +/-75vdc 10 amps . And i want to put that smps on job. What will be the best option SR200 or A40? Which amp have low THD and good temprature average. My speakers are peavey SP2. Thanks for your precious feedback.
 
apexaudio

apexaudio

Member
Joined 2010
shahzad831 said:
Thanks for feedback guys. Actually i have some numbers of orignal sankens in stock ao i want to utilize them in a40 or sr200 . Issue is this, that i have an SMPS (based on 2110 3525 ETD 59 DIY) whos output is +/-75vdc 10 amps . And i want to put that smps on job. What will be the best option SR200 or A40? Which amp have low THD and good temprature average. My speakers are peavey SP2. Thanks for your precious feedback.
Click to expand...

Your option is A40, SR300, B500, HV23...
 
S

shabusf

Member
Joined 2010
Hello Friends, Below are my build details. Trafo: 39-0-39, 5A per channel. Dual Mono. Drivers: MJE15028/29 (rated @120v, but i hope it is okay for +-54v dc ) sourced from RS components. Outputs: Toshiba 5200/1943, sourced from taydaelectronics. BC550/BC560/BD139/MJE340/50 - Sourced from RS Components.

I used Alex MM's 1.4v PCB (the offset series resistor should be 470k, that is the only change from the silk, otherwise populated components as per the silk). If you use 1.5v PCB, silk is having the correct value 470k it seems.

Bias: ~45mA, Offset +-5mV

Use genuine components, your amp will be up without any issues. And of course you will never get disappointed with the sonic, a great sounding amp :)

As of now I have only two pairs at the output, adding the other one soon.

Happy time for the Apex A40 fans :)

YouTube

Regards, Sha
 
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