BF862 based SE Class A Headamp without the HEAT

[Julian RO]

It looks good but my headphones are AKG712-812. 😀
What happens if we put a few more 2sk209bl?

 

[xrk971]

Each is good for maybe 10mA. You need about 120mA for 32ohm cans. You might want to match those JFETs to reduce chances of current hogging.

 

[Julian RO]

Because I have some smd 2512 resistors, I thought of making a pcb for them.
The output capacitor will sit horizontally on the pcb, not vertically.

 

[xrk971]

Nice work. Looking forward to seeing the build.

 

[vdupham]

Hi can you share schematic with volume pot ?

 

[kees52]

Where can I get the bf862? because I had order it on ali, but these are mosfets reprinted, I am
for a punishment for this sellers, hoppa into jail.

There are maybe good ones, but difficult to see.

By the way Europe Union is started investigation into this fake business from China and ali/ebay.

 

[shattered_dream]

Hmmmm....
This amp suitable for a 250 ohm headphone ?

 

[twocents]

I was looking for a small portable amp for my DT880-250 headphones. I wanted class A and I wanted longer battery life and low rejected heat.

First sentence of this thread should answer your question.
If you have BF862 - don't hesitate. Build this little amp. Sounds gorgeous.

 

[xrk971]

Hmmmm....
This amp suitable for a 250 ohm headphone ?

Yes.

 

[shattered_dream]

First sentence of this thread should answer your question.
If you have BF862 - don't hesitate. Build this little amp. Sounds gorgeous.

Nope, built the 2sk209BL Version since I didnt have the chance to get hands on the BF862...
Just asked cause I am thinking about buying a DT990 Pro 250 Ohm version...

 

[xrk971]

The 2sk209bl will work even better as it can handle a higher voltage. This will let you push higher volts for higher impedance cans (not that 18v was lacking with the BF862’s).

 

[shattered_dream]

I got the version made from Julian RO with the integrated psu, which delivers 12,2V.....
Got it today, and testing now right at the moment... Sound is quite good 😀

 

[Julian RO]

You can change the value of the resistor at the ADJ pin for more volts.
The value/quality of the output capacitor is also very important.

 

[shattered_dream]

Still using it with the 12 V... More than enough power...
Output caps are Nichicon fine gold caps I had in my closet....

Btw fantastic sounding amp especially if U use a good sound card...

 

[Julian RO]