Class A amp with fully symmetric design using only NPN output transistor

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any design to extend the amplifier stage.tem

I would be using separate step up system/power supply stage for extension side. approximately 40+/- rails using 1500VA from 12v car battery.

1. How much bias for 5200/4913 pairs.
2. How much base and emitter resistors ( i am aiming 10 pairs for one channel)
3. Pd around 300 W continous to get around 150 W pull push Class A
4. How to get output from emitters, of existing output stage.
regards
 
Hi i intend to make a 200-600W pure Class A amp.
My limited knowledge has limited to ouput device matching.
My best shot is a stock of 2SC5200 transistors.
Is there any simple design for class A pull push type using only NPN in output stage?
Reason:available 5200 transitors, 48 of them and no dismilarity in turn-0n turn off time associated with complimentary pair.
regards
There are different topologies, not all easy to find online, because the most usual is the so called "True Complementary" for the power output stage.
Check out this threads to get an overview of all me known topologies:
http://www.diyaudio.com/forums/soli...e-ended-related-solid-state-output-stage.html
http://www.diyaudio.com/forums/soli...-models-quasi-complementary-power-output.html
http://www.diyaudio.com/forums/solid-state/189599-my-little-cheap-circlophone.html
http://www.diyaudio.com/forums/soli...tion-parts-accessories-beginner-friendly.html

It is worth bearing in mind that with a real musical signal, as opposed to sinewaves, the maximum efficiency will be around 1% at full throttle. (Just clipping) It will be essentially a 1200W room heater.

I do not encourage people to build large Class-A amplifiers. They are grotesquely inefficient, and that offends my engineering sensibilities.

I think the same. OTOH - until now I haven't heard a Class AB amp that sounds as good as pure class-A - at least in full-range applications.

Therefore my favorite set-up is a multi-amping system with a pure-Class-A only for the tweeter (high-frequency part) because an output power between 2W and 20W is mostly enough. "ZEN", "DOZ" and "JLH" are good, in special cases the "Power Follower" from Mr. Andrea Ciuffoli.

In the low frequency aera (up to 500 Hz) the complex distiortion from AB outputs doesn't any matter - thus typical AB amps like your "blameless" topology meets all requirements in such cases, if there a "low-compression" power supply is in use at the same time.
For me still unknown is the question, from which overtaken frequency the complex distiortion from AB is clearly audible and a class-A amplifier will be necessary. Perhaps here you have experiences.
 
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exactly the reason i want the Class A amp here. and why i am using the FOcal amp circuitry because its very well built and i dont have to built from scratch every thing particular small signals/pcb etc, i can just jump to class A output stage with a proper power supply and high biased closely matched BJT pairs/,.

any guidance here?
 
any design to extend the amplifier stage.tem

I would be using separate step up system/power supply stage for extension side. approximately 40+/- rails using 1500VA from 12v car battery.

1. How much bias for 5200/4913 pairs.
2. How much base and emitter resistors ( i am aiming 10 pairs for one channel)
3. Pd around 300 W continous to get around 150 W pull push Class A
4. How to get output from emitters, of existing output stage.
regards
1. Depends on load (speaker) impedance.
4. The existing output stage is most likely class AB. Adding a class A booster will not improve distortion or sound quality.
 
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This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.