Dear Greierasul,
I follow your thread since I give you my ideas to improve your circuit distortion based in simulation.
It was funny as we both fail in lost of output inductor to prevent instabilities.
I love complex amplifier with high performance.
If possible I wonder to see schematics of SARA-2012 even if it was only for my eyes in a PM form.
Thank you in advance.
Ronaldo
Dear greierasul I have a few more questions.
Which transformer can I use (large and current)?
I also saw an example of a PSU but for the rest no data, like
Parts and possibly gerbers? Can you help me?
Regards
Hans
Which transformer can I use (large and current)?
I also saw an example of a PSU but for the rest no data, like
Parts and possibly gerbers? Can you help me?
Regards
Hans
Hello! The archive with sara-2016 gerbers contains, indeed, two other folders: one with an adapter for the double non-inductive output transistor emitter resistor and the other one with a test power supply (it wasn't tested yet). Both folders contains eagle files (.brd,.sch) and evrebody can modify them as they wish.
1) The adapter for double emitter resistor is based on two groups made from 3 pieces, 1 ohm, 1watt paralleled resistors.
2) The psu design is based on a National Semiconductor application note. I have used one single rectifier bridge made from 4 MUR 820 diodes and 2x 10000uf/63v electrolytic capacitor on each positive/negative side. In the eagle files you have all component values. When I will finish my amp based on files greierasul posted here, the amp will be a dual-monobloc and each channel will have its own power suplly.
I hope you will find the files posted usefull and there will be many enthusiasts making their own SARA amplifier.
Regards!
You can use any type of transformer, torroidal, E+I, R-Core, with the power bigger then 300VA. I recommand you a 500VA or, why not, bigger if you have enough money for this project.
About PSU gerbers, Palade Vlad can help you better then me. He designed the wiring.
Regards, Raimond
It's not the money but the knowledge, and that's why I want to do it well and I'm dependent on other people who want to help me, so I'm happy with
the information
Regards Hans
the information
Regards Hans
Tell me more about your loudspeakers: impedance vs phase vs frequency. That information it is important for choice the correct power supply.
Very nice speakers...I know them. An 500VA transformer will be more than enough. The speakers has a minimum impedance of 3.2ohm at 110hz. For the transformer, if you can, choose the quality to the detriment of the price. Some toroidal transformers are for the industrial tasks and the price it is lower, but for audio are too acoustic noisy, etc.
The electrolityc caps used by me in the psu design are rated at 63v dc. Their outer diameter is 36mm. The max voltage you can use is given by the max voltage of the capacitors you have used. If you use a transformer wich gives you 40v
In the secondary you will have about 56 V DC after the rectifier.
I can answer this question to you. I recomand you a 50Vcc...55Vcc at the amplifier module. So, at the output of the transformer, at secondary winding, it is nice to have a 38Vac. You have to keep in mind that voltage is growing sometime, with 10% in legal terms.
So, you can choose any voltage between 38Vac...40Vac.
Mr Greierasul There are also pdf files of the power supply to be able to etch them
For the sara 2016.
Purrhula
For the sara 2016.
Purrhula
Mr Purrhula, I do not quite understand the "etch" term. Can you reformulate, pls ?
I mean that I want to make the psu myself from coperboard
At message 123, I received an answer to one of my questions
I can not open that file. I do not have the good program
At message 123, I received an answer to one of my questions
I can not open that file. I do not have the good program
I spoke with Vlad for pdf's with drawings of the power supply. When are ready he will post them.
You have the pdf files for the psu.
@sesebe- Thank you for your sustained advice regarding the pcb design (you were my peer reviewer) and for the measurments made on the test module!
@sesebe- Thank you for your sustained advice regarding the pcb design (you were my peer reviewer) and for the measurments made on the test module!
Some measurements with SARA-2016. Small signal bandwidht (-3db) - 850khz. Slew-rate - 100V/us. THD-1khz 8ohm 0.001%. THD-20khz 8ohm 0.004%
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