Hi everyone. From an academic sense, I know very little about power amplifiers and circuits. I have learned a great deal about amplifiers from YouTube and the DIY audio community. To gain some understanding of the fundamental construction of a transistor amplifier, I have collected some circuit diagrams related to amplifiers from the internet and some sketches from the PCB. what I have learned or what experience I have gathered, or, you may say, stolen, 🙂 which I wish to implement on my own designed PCB. This ambition led me to create this schematic. In order to create the amplifier, I would like to ask that you provide some valuable advice and constructive criticism prior to routing the PCB.
🙂
Thanks
OPU
🙂
Thanks
OPU
Attachments
I appreciate your concern, Rayma. It looks like I'll need an oscilloscope and a resistance of about 200 W/8 ohm. Although Hantek/UNI-T is available, I am seeking for a Rigol oscilloscope, which is not available in our market.
I dont have variable lab supply but I have 5 transformer which are 12-0-12 to 50-0-50. those transformers are collected from old sony sets
Maybe you could give a little more info like the class, design criteria, application, etc. That would help anyone provide useful feedback.
As mentioned above, the amp depicted in your schematic is not of a first time build for anyone and will certainly be challenging and expensive.
Also, you didn’t include the drawing for the +/- 70V power supply - the foundation of the entire amp.
As mentioned above, the amp depicted in your schematic is not of a first time build for anyone and will certainly be challenging and expensive.
Also, you didn’t include the drawing for the +/- 70V power supply - the foundation of the entire amp.
@techtool I appreciate your input. Actually, I had already purchased an amplifier PCB, assembled it, and turned it on. This time, all I did was attempt to create a somewhat professional-looking design. I left the power rail circuit out of this design because it will be on a separate PCB. There isn't room to draw another diagram because I tried to draw the diagram on a single sheet.
How many of these can you afford to blow up? How much of this is your own design and how much is copied from other amps? I.E. how much of the details do you understand? I see you have copied a couple perhaps "bad ideas".
A drawing like this is the last step, and not the first. First you start with simulations and breadboards to prove each part of the circuit. Once you know your design is solid, then you can document it in a big schematic like the one you posted. Trying to "top-down" design an amplifier is a bad idea. You need to spend a lot of time with cheap little amplifiers before you blow a lot of money on a huge failure. It is foolish to think that you know something that the experts have overlooked.
A drawing like this is the last step, and not the first. First you start with simulations and breadboards to prove each part of the circuit. Once you know your design is solid, then you can document it in a big schematic like the one you posted. Trying to "top-down" design an amplifier is a bad idea. You need to spend a lot of time with cheap little amplifiers before you blow a lot of money on a huge failure. It is foolish to think that you know something that the experts have overlooked.
Thank you for sharing the useful documentation and for your insightful remarks. It occurred following yesterday night's resistor changes. 50 - 0 - 50 AC/10A transformer is my preferred choice.
The $64k question is - Is this really the very first amplifier ever attempted or just the first “serious” one, after building his fill of 12 volt amplifiers, E-bay China kits that don’t put out advertised power, and chip amp projects? That makes a huge difference.
I'll install everything except the power transistor in my initial effort, and then I'll experiment with +/-18 volts to see how well the audio portion functions. Next, I'll add a single pair of power transistors, raise the voltage, adjust the bias voltage, and calibrate the offset voltage. thus I'll complete the task gradually.
possibly Even though this is a really desperate attempt, I'm willing to learn from any unpleasant experience as I try to make my own PCB. then what will I lose—just a little money? as I always do!! 🙂