Reddit reviews Designing Audio Power Amplifiers
We found 3 Reddit comments about Designing Audio Power Amplifiers. Here are the top ones, ranked by their Reddit score.
Reddit reviews Designing Audio Power AmplifiersWe found 3 Reddit comments about Designing Audio Power Amplifiers. Here are the top ones, ranked by their Reddit score.
I think it was unwise to make such a drastic change to R17 from your circuit of two days ago. It used to be 50 ohms; now you've changed it to Infinity ohms???
If you're using Bob Cordell's textbook please refer to pages 64-67. If you're using Douglas Self's textbook please see pp. 143-4 and especially Fig 6.4(b).
I also think if your output power is 150W RMS per channel, you had better split Q14 into 3 parallel transistors (each with its own emitter resistor). Same with Q15. This will reduce the power dissipation per transistor by 3X, and since Ic per transistor is 3X lower, beta droop at high currents (and fT droop at high currents) are less.
When you build a 300 watt stereo amplifier that operates in the audio frequency band, the majority of cost is going to be the power supply and the power output stage. You'll need a power transformer rated approximately 800 VA like THIS ONE which will set you back about a hundred bucks including shipping. You'll also need some big ass filter capacitors rated for >9 amperes ripple current, such as THESE. You need to create +76VDC and -76VDC (assuming an 8 ohm load and Vpeak = Vsupply minus 6V due to rectifier+ripple+emitter follower drops). The supply voltage will be higher if you user power MOSFETs instead of power BJTs. To handle 300 watts per channel you're probably going to need at least 4 power-PNP transistors and at least 4 power-NPN transistors, per channel. Representative transistor prices HERE and HERE
You'll also need big ass heatsinks, big ass fuses, and big ass rectifiers.
Have a look at books by Randy Slone, Bob Cordell, and Ben Duncan. AMAZON-1, AMAZON-2, AMAZON-3
Since the majority of cost is in the high-power circuitry which you absolutely require, you won't save much money by deliberately making the amplifier "low fidelity" rather than "high fidelity". Sorry.
In that case, I bet you'll want to take the custom route. Have a pair custom made for yourself and you'll never go back to the generic ones. Here are a few resources to get started. [1], [2], [3], [4], [5].