Toroidal coil

dcbingaman

Joined Jun 30, 2021
1,065
That an inductor-loaded class-A amplifier is a viable circuit.


The original circuit was meant to be an inductor-loaded class-A amp, presumably derived from Nelson Pass's "Zen" series, with a few errors introduced.
Thanks for the clarification. You have definitely shown an inductor loaded class A amplifier is viable.
 

LowQCab

Joined Nov 6, 2012
5,101
How about just making it into a Bridge-Amp,
and eliminating all that Bias through the Speaker ?

Any one who thinks they need a Class-A Amp deserves what ever they get.
But I guess they're required if You want real "Musicality" and "Sound-Stage".
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Thread Starter

TieBravo

Joined Aug 21, 2021
60
T
You found a useless audio power amplifier circuit.
The coils cut high audio frequencies.

I changed its transistor and base resistor value for a higher output power.
I simulated it to show that the output power is 1.8W with severe distortion.
The speaker and transistor each heat with 4.5W all the time even when not playing sounds.
The DC in the speaker causes its cone to be pulled over to one side causing more distortion.
The input impedance is less than only 2 ohms.
Thank you
SPICE simulations don't mean anything for those people to whom Baranek's law applies!
I got my facts wrong - the silver bullet kills a werewolf, not a vampire. View attachment 246461View attachment 246462

Here's what you can do if you add a handful of small signal transistors. (If you insist that a handful means five then the BCV61 is a dual.) MY version of Spice doesn't have the 2SC5200 so I substituted an MJL3281A.
Spice predicts 0.02% for the distortion, mainly 2nd harmonic.
0.3Ω is the DC resistance of the choke. The bias sets about 500mV across the choke resistance to give a standing current of 1.8A.
Thank you.
 
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