Great project! Two 12v Li-ion batteries would make an awesome PS!
I am not so sure. Can such batteries really handle 1.40A, the bias in output.
But 12V lead batteries like in cars would do it.
I would first lower the current bias in output. That is done by changing R1 and R15 to a higher value.
Let's say we target for 100mA instead of 1.40A.
I would then change the gain of the circuit. Lower R6 to 2.2k or so.
That's it.
Maybe add a resistor out from the output. 47 Ohm or 100 Ohm I guess.
Another thing is we might need some slowstart of the amplifier.
It would take some minutes before the output is stable.
This Class A will certainly have a warm up process.
Can be a relay.
ACA Mini is my favorite amplifier, too. But have not tried it.
Nice to hear about your batteries.
Nice to hear about your batteries.
Yeah.... those big guns are mounted inside the metal enclosures that ring link church bells. Plus, there's a fair bit of hook-up wiring, extra solder joints / terminal block connectors...
But that little ACA Mini... no wonder it sounds lovely. No hook-up wiring (apart from a short LiPO battery wiring run), connectors soldered directly to the PCB... and the best thing... you used heavy plastics to mount the PCB. That makes a huge difference.
But that little ACA Mini... no wonder it sounds lovely. No hook-up wiring (apart from a short LiPO battery wiring run), connectors soldered directly to the PCB... and the best thing... you used heavy plastics to mount the PCB. That makes a huge difference.
Here is my suggestion for your 70 Ohm headphones.
Actually it has even more clean output. Distortion is very low. THD 0.00025%
I had to increase C2 to 100pF.
Also note the resistors R1 and R6. They are changed.
Also added a resistor in the output: 47 Ohm
The bias is 175mA in the output LU1014D.
Here is Nelson Pass liked variation with Relay Delayed Start.
When I test it in SPICE the delay is now 22 sec before the speaker is connected.
It is to protect loudspeakers.
The delay can be adjusted by changing a capacitor C6.
Otherwise I have not changed this All FET variation.
It is a good little amplifier that should be okay to drive 8 Ohm or 6 Ohm speakers.
Those JFET has that good sound that Nelson Pass has demonstrated in his work.
When I test it in SPICE the delay is now 22 sec before the speaker is connected.
It is to protect loudspeakers.
The delay can be adjusted by changing a capacitor C6.
Otherwise I have not changed this All FET variation.
It is a good little amplifier that should be okay to drive 8 Ohm or 6 Ohm speakers.
Those JFET has that good sound that Nelson Pass has demonstrated in his work.
@Nelson Pass
Hope you will.
I have no means to do the real work.
I just play with SPICE and try to do my best in producing schematics.
Why not make a First Watt PDF and there you can add details if necessary.
You can make this project go further.
If you publish at First Watt the demand will go sky rocketing 😀
You already have been very helpful here. Because you like this amplifier idea.
Besides you have all the components. Why not offer a kit?
Make this amplifier yours. You only have to mention me a bit.
Stefan Forslund also known as lineup and halojoy
Lycksele
Sweden
Hope you will.
I have no means to do the real work.
I just play with SPICE and try to do my best in producing schematics.
Why not make a First Watt PDF and there you can add details if necessary.
You can make this project go further.
If you publish at First Watt the demand will go sky rocketing 😀
You already have been very helpful here. Because you like this amplifier idea.
Besides you have all the components. Why not offer a kit?
Make this amplifier yours. You only have to mention me a bit.
Stefan Forslund also known as lineup and halojoy
Lycksele
Sweden
Papa, I could help with putting kits together. I’m sure 6L6 will be of help as well.My question is: Are we going to build a batch of these?
https://www.diyaudio.com/community/threads/faow.325037/post-5493544
"The problem with the Lu1014 is that I have not had good success making it behave itself outside of a cascoded situation, and stopped trying after a while.
But seeing as I have about 7000 of them, maybe I should take another look."
Real life problems (or shall we say challenges) that does not exist in Spice.
But that's what makes it interesting, even after 5 years.
🤓
Patrick
"The problem with the Lu1014 is that I have not had good success making it behave itself outside of a cascoded situation, and stopped trying after a while.
But seeing as I have about 7000 of them, maybe I should take another look."
Real life problems (or shall we say challenges) that does not exist in Spice.
But that's what makes it interesting, even after 5 years.
🤓
Patrick
Michael's FAOW example is the only one I can find that is outside a cascode, in real life.
https://www.diyaudio.com/community/threads/faow.325037/post-5494704
https://www.diyaudio.com/community/threads/faow.325037/post-5494938
And even that was not without challenges :
https://www.diyaudio.com/community/threads/faow.325037/post-5501325
Patrick
https://www.diyaudio.com/community/threads/faow.325037/post-5494704
https://www.diyaudio.com/community/threads/faow.325037/post-5494938
And even that was not without challenges :
https://www.diyaudio.com/community/threads/faow.325037/post-5501325
Patrick
Last edited:
https://www.diyaudio.com/community/...-watt-with-low-distortion.397378/post-7307448
You can of course change all the Toshiba's to Onsemi's etc.
🙂
Patrick
You can of course change all the Toshiba's to Onsemi's etc.
🙂
Patrick