ZVN4306GTA has been work horse for my Pocket Class A. Sounds great. It has a complemtary P channel.
If you don’t mind TO220, IRF610 and 9610 are good. Recently I started using Fairchild FQP32N20C. They are excellent as well. Probably lower distortion than IRF’s.
If cost no object, some new (old stock) Toshiba 2SK2013 and 2SJ313’s are excellent. Beware of fakes.
If you don’t mind TO220, IRF610 and 9610 are good. Recently I started using Fairchild FQP32N20C. They are excellent as well. Probably lower distortion than IRF’s.
If cost no object, some new (old stock) Toshiba 2SK2013 and 2SJ313’s are excellent. Beware of fakes.
Sure there are books and the ones by Self and Cordel are excellent books on amplifiers in general. HP amps are just a subset of lower power lower noise amps. Because they are lower power and demand the highest performance in terms of noise and distortion - Class A is the perfect way to go. A good way to learn is to get LTSpice and start with a current design that’s proven. Start simple - like the 2 transistor SE Class A pocket amp that I made. Ask questions in the forum and work through the problems. You will get both theory and practical hands on experience as you try to design your own amp on the forum. It’s better than a book trust me.
Thanks man .
I will surely go with your method . Specially diyaudio is friendly community. You also are so awesome.
Any way which diode bridge is best for 15v supply? Which toroidal transformer I should choose to get 15-0-15? I am so confused. Is their any modern alternative to 7815 and 7915 regulator?
I will surely go with your method . Specially diyaudio is friendly community. You also are so awesome.
Any way which diode bridge is best for 15v supply? Which toroidal transformer I should choose to get 15-0-15? I am so confused. Is their any modern alternative to 7815 and 7915 regulator?
For a headphone amp, you will be happy with a 50VA toroidal transformer. 7815:7915 in TO220 are fine for getting started. You can get TI TPS7Axxx regulators integrated into a small TO220 78xx/79xx style package from eBay for $10 to $15. They are 4uV rms for positive and 14uV rms for negative.
You can also avoid trafo and dangerous AC mains by getting a DC-DC converter and use 12v wall wart to power.
That’s what I am doing in latest amp - and the PSU is quiet like a battery. It’s more expensive than trafo/bridge/caps/7815-7915 option though.
See here for details on the new DC-DC psu - gives up to 310mA of +/-18v from 12v wall wart.
Simple High Performance DC Coupled Class A HPA with sub PPM THD
Here are the TPS7Axxxx regulators
Here is the 11W dual rail PSU:
Here is measured noise performance. Note lack of any mains AC peaks or harmonics:
But to get started, the trafo linear supply is a good start. Lower cost too. Just be careful with AC mains voltages and proper earth grounding.
Btw, qnty 6 x 6v sealed lead acid batteries (+/-18Vdc) will run a class A HPA for a long time (20hrs or more depending on bias current).
You can also avoid trafo and dangerous AC mains by getting a DC-DC converter and use 12v wall wart to power.
That’s what I am doing in latest amp - and the PSU is quiet like a battery. It’s more expensive than trafo/bridge/caps/7815-7915 option though.
See here for details on the new DC-DC psu - gives up to 310mA of +/-18v from 12v wall wart.
Simple High Performance DC Coupled Class A HPA with sub PPM THD
Here are the TPS7Axxxx regulators
Here is the 11W dual rail PSU:
Here is measured noise performance. Note lack of any mains AC peaks or harmonics:
But to get started, the trafo linear supply is a good start. Lower cost too. Just be careful with AC mains voltages and proper earth grounding.
Btw, qnty 6 x 6v sealed lead acid batteries (+/-18Vdc) will run a class A HPA for a long time (20hrs or more depending on bias current).
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TPS7Axxxx
This fet look like interesting replacement for bf862.
I got 50 bf862 from eBay . They turned out to be fake one.
I thought my circuit was wrong so they got burned but when I used on a car radio with bf862 , it didn't work .
I am scammed!
Bf861 in verge of EOL
Why NXP semiconductors discontinue such a great product.
http://www.onsemi.com/pub/Collateral/ENA1965-D.PDF
This fet look like interesting replacement for bf862.
I got 50 bf862 from eBay . They turned out to be fake one.
I thought my circuit was wrong so they got burned but when I used on a car radio with bf862 , it didn't work .
I am scammed!
Bf861 in verge of EOL
Why NXP semiconductors discontinue such a great product.
http://www.onsemi.com/pub/Collateral/ENA1965-D.PDF
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TPS7A I know are regulator I bought completely assembled PCB from eBay. StillI haven't tried them.
I will try to find bf862 locally.
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