hello.
Some time ago I bought a portable amplifier for my work that works with power from a USB port (5v-20v).
I also bought him a power converter from 5v to 12v. to make it work with a little more power.
I bought all this on aliexpress for a few dollars.
sounds decent for the price. but I want to take it further for fun and experiment.
I already changed the op-amp. It came with a ne5532p and I put a muses02 on it. the sound improved noticeably.
now new capacitors are about to arrive (nichicon KW and some nichicon film to put them in parallel to the KW. I wanted to put some KZ but they don't fit).
I would also like to change the transistors and this is the reason for this thread.
Since the op-amp and capacitors it originally comes with are low-medium quality, I'm assuming the transistors are too.
It has 1 transistor D882P and 5 transistors of a plastic material in which only a letter K is distinguished.
transistor D882P is NPN. the others I don't know...
which audio transistors would be the best replacement for my low voltage mini amp?
also the power supply (the 5v to 12v converter) picks up some noise when my laptop is connected to the charger even though i bought a usb isolator (ui501) for it.
the isolator block some of the noise but not all of it. The noise is felt when I use headphones but not on speakers.
I changed a couple of capacitors, but the noise is still there. maybe placing some capacitors in parallel can fix something?.
any advice?
I attach the links of both products:
Douk Audio U3 mini amp:
https://es.aliexpress.com/item/1005...f16512738927277811e015e|12000017626492931|sea
Converter 5v a 12v:
https://es.aliexpress.com/item/3300...816512741597555192ea1d8|12000018800586971|sea
usb isolator ui501
https://es.aliexpress.com/item/4000..._list.0.0.21ef194dceDFe8&gatewayAdapt=glo2esp
I attach photos too.
hope you can help me.
sorry for my grammar i'm not native english speaker.
Regards.
Some time ago I bought a portable amplifier for my work that works with power from a USB port (5v-20v).
I also bought him a power converter from 5v to 12v. to make it work with a little more power.
I bought all this on aliexpress for a few dollars.
sounds decent for the price. but I want to take it further for fun and experiment.
I already changed the op-amp. It came with a ne5532p and I put a muses02 on it. the sound improved noticeably.
now new capacitors are about to arrive (nichicon KW and some nichicon film to put them in parallel to the KW. I wanted to put some KZ but they don't fit).
I would also like to change the transistors and this is the reason for this thread.
Since the op-amp and capacitors it originally comes with are low-medium quality, I'm assuming the transistors are too.
It has 1 transistor D882P and 5 transistors of a plastic material in which only a letter K is distinguished.
transistor D882P is NPN. the others I don't know...
which audio transistors would be the best replacement for my low voltage mini amp?
also the power supply (the 5v to 12v converter) picks up some noise when my laptop is connected to the charger even though i bought a usb isolator (ui501) for it.
the isolator block some of the noise but not all of it. The noise is felt when I use headphones but not on speakers.
I changed a couple of capacitors, but the noise is still there. maybe placing some capacitors in parallel can fix something?.
any advice?
I attach the links of both products:
Douk Audio U3 mini amp:
https://es.aliexpress.com/item/1005...f16512738927277811e015e|12000017626492931|sea
Converter 5v a 12v:
https://es.aliexpress.com/item/3300...816512741597555192ea1d8|12000018800586971|sea
usb isolator ui501
https://es.aliexpress.com/item/4000..._list.0.0.21ef194dceDFe8&gatewayAdapt=glo2esp
I attach photos too.
hope you can help me.
sorry for my grammar i'm not native english speaker.
Regards.
That´s often called "making a silk purse out of a sow´s ear" or in less polite terms: "polishing a turd".
Sorry.
Sorry.
Kill the dog which bit you.
Seek attention if needed.
Buy a 12V amp, with supply, you will spend less than what you have spent on parts and get better performance.
Don't waste time, money and energy polishing a turd.
Seek attention if needed.
Buy a 12V amp, with supply, you will spend less than what you have spent on parts and get better performance.
Don't waste time, money and energy polishing a turd.
hi.
I have seen better amps but they are big and bulky.
this mini amp is super small and portable that's why i bought it. I can carry it comfortably in
a pocket of my backpack to my work without being anoying.
I could use it with a laptop transformer like the one in the photo but it is too bulky to carry it around in my backpack all the time. that's why i bought him
the adapter from 5v to 12v.
Any suggestions for changing transistors?
I have seen better amps but they are big and bulky.
this mini amp is super small and portable that's why i bought it. I can carry it comfortably in
a pocket of my backpack to my work without being anoying.
I could use it with a laptop transformer like the one in the photo but it is too bulky to carry it around in my backpack all the time. that's why i bought him
the adapter from 5v to 12v.
Any suggestions for changing transistors?
Keep the amp at work, unless there is a problem with that.
Or buy / build a work radio.
Use the laptop charger as supply.
You can use Bluetooth speakers to listen to music off your laptop or cell phone...
See the solution, the 5V amps are toys compared to bigger units, you want music at work...that is the requirement.
Or buy / build a work radio.
Use the laptop charger as supply.
You can use Bluetooth speakers to listen to music off your laptop or cell phone...
See the solution, the 5V amps are toys compared to bigger units, you want music at work...that is the requirement.
"I have seen better amps but they are big and bulky."
CADISI U301, rebranded as Douk U3, external power supply
112 x 69 x 32mm, 180g
Aune B1s, including built in 4000mAh battery
125 x 65 x 18mm, 230g
If your purpose of posting here is to get a better amp, then buy something well engineered, like the Aune.
If your purpose is to learn electronics and enjoy DIY, then buy a starter's kit with a schematics and solder and debug from scratch.
If you believe in reaching heaven by swapping a few parts without understanding, then I doubt anyone here can help you.
But maybe Douk can.
🙂
Success,
Patrick
CADISI U301, rebranded as Douk U3, external power supply
112 x 69 x 32mm, 180g
Aune B1s, including built in 4000mAh battery
125 x 65 x 18mm, 230g
If your purpose of posting here is to get a better amp, then buy something well engineered, like the Aune.
If your purpose is to learn electronics and enjoy DIY, then buy a starter's kit with a schematics and solder and debug from scratch.
If you believe in reaching heaven by swapping a few parts without understanding, then I doubt anyone here can help you.
But maybe Douk can.
🙂
Success,
Patrick
And this is what I would call a compact, lightweight, USB-powered headphone amp.
Capable of +/-8V output. Powered by USB port only (any laptop with USB3.0).
Will drive a AK702 to deafening sound level.
But just material alone is more than 40USD.
https://www.diyaudio.com/community/threads/new-audio-op-amp-opa1622.283672/post-4953256
Cheers,
Patrick
Capable of +/-8V output. Powered by USB port only (any laptop with USB3.0).
Will drive a AK702 to deafening sound level.
But just material alone is more than 40USD.
https://www.diyaudio.com/community/threads/new-audio-op-amp-opa1622.283672/post-4953256
Cheers,
Patrick
Last edited:
You can convert USB 5vdc to compact +-12vdc, tiny filter caps, for example....
https://www.diyaudio.com/community/threads/simple-head-amp-tests-rkz-0512-switcher.364547/