Studio Reference Amplifier

viki_v2 it's ok ,now you can solder trasistors ,and go one step forward...;) Output inductor , it's in circuit to do an filter, and Zobel also .
You must solder, in paralel with output inductor ,10 ohm/3w resistor (inside coil). Transistors will be mounted on large heatsink insulated with mica and silicon grace .:)
Regards Alex.
 
Hello,
OK, I have not paralleled the resistor to inductor, Will do it.

Alex I mounted the transistors, and connected to psu.
Fired up and connected to mobile phone---- No sound.
Mobile disconnected Touch input pin with hand it make lots of noise and 22e resistor on psu gets extremely hot.
Checked all the connections.
Checked for shorts- No shorts.
Checked transistors for short to heat Sink- No short.
Disconnected speaker gnd from psu gnd- Psu resistor does not get hot, Connect again gets hot.

what Could be the problem

I am trying to paste images, But no option is coming.
 
Hello,
OK, I have not paralleled the resistor to inductor, Will do it.

Alex I mounted the transistors, and connected to psu.
Fired up and connected to mobile phone---- No sound.
Mobile disconnected Touch input pin with hand it make lots of noise and 22e resistor on psu gets extremely hot.
Checked all the connections.
Checked for shorts- No shorts.
Checked transistors for short to heat Sink- No short.
Disconnected speaker gnd from psu gnd- Psu resistor does not get hot, Connect again gets hot.

what Could be the problem.

And how do I Measure and adjust the Bias, Please Show exact procedure, I have never done it before.
 

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Hello,
Sorted the problem Short at two places.
Now amp is superb sounding. Will Populate second pcb to complete stereo set. Not checked the bias still, Please help.
What upgrades should i try.
I will Be Trying 2sc2922 - 2sa1216 instead of 2sc5200 - 2sa1943.

Apex and Alex thank you very much for the design.

Do you have any smps design for this amp.
 
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Hello,
Sorted the problem Short at two places.
Now amp is superb sounding. Will Populate second pcb to complete stereo set. Not checked the bias still, Please help.
What upgrades should i try.
I will Be Trying 2sc2922 - 2sa1216 instead of 2sc5200 - 2sa1943.

Apex and Alex thank you very much for the design.

Do you have any smps design for this amp.

Nice work, I suggest SMPS PSU only for PA amps.
Regards
 
Nice work, I suggest SMPS PSU only for PA amps.
Regards

Thank You Mile,
I was asking about smps as Good quality transformers are not easily available at my place.

Mile I want to share a experience as well as ask your suggestions. I use my mobile phone for my music it is Nokia with Sony earphones it sounded good. Some months back i purchased a 90$ Denon earphone, for this handset , As I plugged the earphones , the sound was very good much much better than the sony earphones which had. The bass was solid with clean sound. I was very happy.
Then One day a friend of mine purchased a Micro max mobile phone which utilizes Wolfson Chip and codecs. I plugged my Denon earphones and Wow The sound was something like I had never Heard before, The vocals had amazing depth .The highs were very crisp never harsh, Bass was So solid Deep and punchy. It was like stepping in some new world this type of sound i never knew existed.

Just what a difference The wolfson Chip made.
Same way what is that something which We can do which will give the same amazing audio quality bring the depth for which we all crave.

Thank You
 
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D

Deleted member 148505

Hi Viki_v2 and Apexaudio,

How's the bass sound? Is it fast and crisp?
I'm planning to build a subwoofer amp about 200w-300w @4ohm, powered by 38-0-38 AC transformer. Is this better than b500?
I didn't like sr200 because mosfet transistors here cost more than bjt.
Thanks
 
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Sr200 Speakers

Viki, what speakers you use for test this amp?
Regards

Hello Mile,
For testing i used bookshelf Speaker 5 1/4" Kevlar cone woofer and 1"Fabric Dome tweeter both from Peerless India.

Floor standers are using two 8" Woofers and 1"Fabric Dome tweeter from Peerless India in MTM configuration.

But now I think I will make it a full 3way Design by modifying the baffle and adding a 5 1/4" midrange woofer.

I am targeting the amp to drive These floor Standers. and Bookshelf's.
As only 1 channel is complete I have not been able to check the big speakers fully.

I do not have any preamp, Signal Input is Mobile phone.
 

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Hi Viki_v2 and Apexaudio,

How's the bass sound? Is it fast and crisp?
I'm planning to build a subwoofer amp about 200w-300w @4ohm, powered by 38-0-38 AC transformer. Is this better than b500?
I didn't like sr200 because mosfet transistors here cost more than bjt.
Thanks

Hello jlester87,
Regarding sound of SR200 Sound is definitely more better than b500 bass is good and powerful, i am powering SR200 with 37-0-37 3 amperes psu one channel still it is so powerful i cant turn the volume even half way, Wonder what will be the output with 75-0-75 6 amperes psu in stereo setup.

I still have to explore it fully as only 1 channel is ready and using a bookshelf speaker for test,will give brief description after stereo setup is complete.

output wise b500 is more powerful.

You better use some class d amp for subwoofer, as using SR200 for sub application would be wastage of a very good design, Ask Mile he will guide he has some designs for sub applications.

regarding mosfets, B500 and SR200 share same transistors

I am using standard components, Will upgrade to premium components to get the best out of it.
 
Hello Mile,
I am having 2 pairs of 2SK1530-2SK201, these transistors are very costly here.
i have read in the forums that these transistors with good design give extremely good sound.

need your suggestions.

I have heard a Rotel $400 Stereo Amp. Want to make amp on par or better than this amp.
 
Hello Mile,
I am having 2 pairs of 2SK1530-2SK201, these transistors are very costly here.
i have read in the forums that these transistors with good design give extremely good sound.

need your suggestions.

I have heard a Rotel $400 Stereo Amp. Want to make amp on par or better than this amp.

You can use 2 pairs of 2SK1530/2SJ201 for stereo FX14 (100W Ultimate Fidelity Amp)
 
Sr200 Amp Assembled second channel

Hello Mile and Alex,
Finished Second channel with 2sc2922-2sa1216 pair.
This time no problems working fine at first start. The pcb seems to be a bit small for components, Not the transistors.

Regarding Sound- There is Big difference. Amp with 2sc2922-2sa1216 has more controlled and defined Bass, Mids are more open and highs are more crisp, Not that first Channel lacks anything , Just the difference I Experienced .

Will have to give more time for both the channels to break in. Some upgrades should bring out the best. These transistors are very well worth Upgrading , only factor is price, Here 2sc5200-2sa1943 sell for 4$ a pair and 2sc2922-2sa1216 sell for 14$ a pair Big difference.

What will be the output with two pairs 2sc2922-2sa1216 at 8 ohms and 4 ohms. Will add another pair soon. MY psu is lower capacity will upgrade it soon.

Chassis will be coming soon, Will Post images when done.

I want to upgrade to better components to find the difference, Can you suggest what upgrades should I do to make this amp sound to its Best.

Will be using this heat sink for 1 channel hope tit is sufficient for full power.
Looking for multi Input selector to change sources.

Can this amp be modified in any way to work with 2sk1530-2sj201.

Thank You.
 

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