have you tried to put say 100 Ohm resistor in parallel to Bluetooth output,and than to input of an amplifier? d-class (Bluetooth output) sometimes needs some load to function correctly.
You can use 10R resistor instead C13 for test module. Power ground and signal ground must be connect with separate wires to PSU if you do not want ground loop and noise.
apexaudio thank you.
It all started when I decided to make my own, correct circuit Board instead of those that are in this topic. (printed circuit Board did 2nd time in my life-1st was TDA7294). And made a few mistakes:
1. transistors bc557 / bc547 in the Datasheet view from below, drew them upside down. It's easy to fix just by turning them.
2. So as not found mje340 / 350 decided to put their replacement 2SB649 and 2SD669, but mixed up pnp &npn. - )))
Now that everything is fixed, it still does not work. Maybe because something got burned (the smell was not) when started with an inverted transistors, or somewhere a faulty product. As luck would have broken multimeter, waiting for a new one. We'll have to solder and recheck....
This is my story-))) I Hope to achieve operation of the amplifier. Well, a few pictures
It all started when I decided to make my own, correct circuit Board instead of those that are in this topic. (printed circuit Board did 2nd time in my life-1st was TDA7294). And made a few mistakes:
1. transistors bc557 / bc547 in the Datasheet view from below, drew them upside down. It's easy to fix just by turning them.
2. So as not found mje340 / 350 decided to put their replacement 2SB649 and 2SD669, but mixed up pnp &npn. - )))
Now that everything is fixed, it still does not work. Maybe because something got burned (the smell was not) when started with an inverted transistors, or somewhere a faulty product. As luck would have broken multimeter, waiting for a new one. We'll have to solder and recheck....
This is my story-))) I Hope to achieve operation of the amplifier. Well, a few pictures
Attachments
Last edited:
Preamp for A40
Hi Mr. Mile,
Could you please suggest the best preamp for A40; its P30 or P30ZF?
Thank you.
Sha
Hi Mr. Mile,
Could you please suggest the best preamp for A40; its P30 or P30ZF?
Thank you.
Sha
hello everyone. i want to make a headphone amplifier so i need a good quality schematic for headphone amplifier. can someone help me?????🙂🙂
Thank you!!
Can you please post the Bias ,off set adjustment and recommended operational Voltage/ power supply rating as well??
Can you please post the Bias ,off set adjustment and recommended operational Voltage/ power supply rating as well??
Thank you!!
Can you please post the Bias ,off set adjustment and recommended operational Voltage/ power supply rating as well??
🙂🙂🙂🙂