Sgheadphones DIY A47 pocket amp kit

[jasonhanjk 0]

NJM4556AD is good because it has better phase shift than OPA2134PA.

Will do further eval when board finish this weekend.

 

Cost for 4556 about $2.00.

[digi01 0]

Thanks Digi 01. I may not use Protel as I am more use to eagle.

By the way, please comment when the PCB design is out. Had seen your masterpiece...

this is my standard comy PCB layout.use 2 opa134 single opamps.ALPS vol mount on boards.wish can give you some ideas

 

[digi01 0]

silk lay

 

 

 

[digi01 0]

if remove the volume pot.the PCB boards size is 37mmx37mm,very minize.I have design a sub-boards for CHA47 hook up.

 

hearty cheers~

[Absolute0 0]

Sounds remarkably fun, but I don't really want to get my hands "dirty", and I don't have a need for a portable amp. Nevertheless, have fun, guys!

[jasonhanjk 0]

Nice. Here's mine:

[jasonhanjk 0]

Board.

[jasonhanjk 0]

Component only:

[jasonhanjk 0]

PCB routing. Too bad only one jumper in red. Try to get 0 next time.

 

61mm lenght and 79mm width. Is this good Tropical? Or you want smaller?

TLE cost $3 so might as well use opamp as virtual ground.

[tropicalrips 0]

i think we can leave out the rail-spilter and use 2 resistors, can the rail-spilter be optional with the mounting already on the PCB?

 

if we want to the PCB to be smaller , the op-amps need to be side by side, but i think that will leave it with at least 1 or 2 jumper wires for power cause the power pins on the op-amps will be crossing each other

 

i'll do a mock-up of the side by side layout to see what has to be done

[jasonhanjk 0]

Ok, new one. I don't really like the 2 resistor as it will fail most of the time. The config will be 3x2 opamp, left, right and ground.

 

Now the PCB is 1.8" x 2.85", about 46mm x 72mm. Mock up??

 

By the way, what pot you want to use?

[jasonhanjk 0]

4 jumpers.

[tropicalrips 0]

3x2 op-amps...left,right and ground... ...meta42... i like where this is going

 

the board layout looks good, if using L/R/G with 3 op-amps, then will the op-amps still be dual or single channel?

 

the jumpers are for the power rite

 

can try with the op-amps turn 90' this will make the board tighter/smaller

 

for the pot, if we going to use a small one, then the mini Alps will be good, its also easier to get then the panasonic pots.

[jasonhanjk 0]

Something like that...

It is dual opamp per channel. One for amplification and the other for buffer. Err, something like Pimeta and A47 combination.

 

Yes, jumper for power. If you want a tighter board I can remove another 2 cap.

Can tell me the board size that you want so that it can fit into a casing.

 

Can have the serial number for pot asap so I can finish design by this weekend....

 

Thanks...

[tropicalrips 0]

for the pot i hav the Farnell no. 919-287-1

but there's 2 versions of the mini alps, one 1 vertical mount, the other horizontal

Alps part no. will hav to check...

 

i prefer 4 caps but i don't think this board will fit into any of my cases, but it will make a good desktop amp