Hi Friends,
Instead of starting new thread i decided to wake up this post from 2013 which is already dedicated for Apex Studio Reference Amplifier “SR 200”. I came across this amplifier during lockdown period it had good reviews on
www.diyaudio.com (
the link for thread has already shared by Mr Bijin) so decided to built one for myself, Later I may sell it. Of-course for funding of next project. I must say this amplifier is one of the best sounding amp. It has the ability to play all kind of music with full power & authority. One of the Best amplifier in its class. This amplifier is capable to deliver 200 watts @ 8 Ohms with 75 VDC rail & I am feeding my amp the same voltage.
Initially my friend Mr. Muthukrishnan helped with DIY boards which were suitable for Sanken transistors. He did a good job, In a good will as a friend he gave me the pcbs without a single penny, not only PCBs he also provided with the OPamp IC and 12 Nos capacitors 470uf/100V. I am really very much thankful to him to provide so much stuff without his personal interest or penny. I was able to get this boards singing but was unable to set the bais. So experimenting with different resistor values and trim pot, it was unfortunate that i did managed to damage the tracks.
So now I decided to make the Boards from JLC. I looked for gerbers on internet and found gerbers from Mr Juan Vargas which he had shared for DIYers like us. Immediately without thinking left or right I placed the Order for PCBs to JLC. I received the PCBs after 20 or 25 days and then started to built my amplifier. This Boards used the transistors 2SC5200 & 2SA1943 from toshiba.
BOM:
Transformer is 50-0-50 AC / 600 VA “R-Core” Shielded from Shilchar. Soft-start & all connectors from diyaudiocrafts, Capacitor Bank & speaker protect pcb was given my our FM
@Aniket , Heatsinks are from Akash Enterprise HS 300 model machined at a local engineering shop as per my dimensions. The complete enclosure is from aluminum sheet 3 mm laser cut and anodized as per my requirement. Face plate is 12.7 mm (1/2") thick machined at a local engineering shop as per my dimensions.
As I have mentioned above... This is indeed one of the best sounding amplifier and dead silent (zero hiss or hum). Enough of write up and sharing some photos of built. I will not be sharing the complete built just the highlights.
Below are the Boards and components provided by my friend Mr Muthukrishnan. Many FM from our forum may know him
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Assembly of his Boards
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Below are the PCBs from JLC. I liked the white color
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R-Core from Shilchar.
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Testing & Bais setting. I managed to blow one cap due to my own mistake. the polarity was reversed, you can also see the green LED besides the capacitor is not glowing. I had to replace all the small transistors to get this PCB running again. (Always there is a lesson to learn) so lesson learned No over-confidence.
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Now coming to the enclosure. The aluminum plates were plain, I was trying for brush finish but ended with this beautiful pattern. I am loving it. The Owner of the anodizing plant said its the problem of material that is why it got its texture.
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Layout
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Wiring. One of my cleanest wiring i can say.
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Today i have given the face plate for machining. Tomorrow i will get it done. Will update more once i am finished with face plate.