PCB based invert 3886 chipamp assembly and comments

[digi01]

this thread is build for talking about 3886inv gainclone and assembling.any suggestion is welcomed.
feel free to post your finished gc.

Series PCB design tips:
AN-1192
BPA200 Application Note
LM3886 DATA SHEET
LM338 regulator
LT108* DATA SHEET
DRV134 DATA SHEET
and,much information comes from Chip Amps forum,thanks everybody🙂

Pcb boards detail:
BLD driver
Regulaotr power supply
LM3886 INV AMP
The size of these three PCBs is totally the same,I like the layout style of tight & compact pattern.I think this way is mentality of designing of GAINCARD too.
I have not designed the unregulated power supply PCB.
If you want to assemble a PCB based unregulator igc,there are two very good unregulator pcb design:
BrianGT's rectifier PCB
peranders ultra fast rectifier bridge
bigparsnip's ultra fast rectifier bridge

cheers
digi

 

[digi01]

3886igc and regulator psu connections.

 

[digi01]

The file releasing😎 attached zip package includes 3886igc +regulator+BLDdriver,gerber output files and nc drill output files.
for gerber viewer,
I recommend CAMtastic,the CAMtastic DXP free viewer supports a wide range of import formats, including ODB++ and Gerber viewer...
url:http://www.altium.com/camtastic/downloads/viewer_rego.asp

enjoys
digi

 

[idex]

Wow, thanks.

 

[jleaman]

Going to be printed tonight and put into book : O ) thanks digi.


I also need to email you about some ideas and questions.

 

[B.I.G]

10x for sharing this with us ! 😉

 

[digi01]

to assemble an integrated stereo amp with regulator power supply.
step by step pic😎
first,for 3886inv boards.
because it is a regulated gainclone,so small caps is all right😀
finally,I use 4x 330uf/50V silmic caps for decoupling.

 

[digi01]

all resistors is KOA SMD for gain setting.

 

[digi01]

second,for regulator PCB.
pic,screw the liner regulaotr on the heatsink first.

 

[digi01]

then solder the big caps finally.the big caps that I used is nichicon 6800uf/50V.

 

[Evilsizer]

looking good! wish i could find some heatsinks like that.

 

[digi01]

thank you Evilsizer🙂
If there is not shipping problems,I am glad to help you to buy some.its price is reasonable.

ok,the end pic.I am still need to find some quality wires to hook up all these patterns.

 

[jawbreak]

Can I buy the boards already printed or anything?
Looks really good, great work!

 

[JimD]

digi

On the 3886 IGC is there any reason why you couldn’t use a 1k/22k or a 620R/20k (for higher gain) resistor combination instead of the 10k/220k combination you specify? Would you need to change the size of the 4.7uf input capacitor if you did use the lower value resistor combinations?

Out of curiosity what is the cost of the heatsinks, size, and what do they weight? Do you know what shipping would be to the states? I would like to get some balanced line driver and regulator boards (if still available) and could use the heatsinks if not too expensive.

Thank you
Jim

 

[digi01]

Hi Jim,

digi
On the 3886 IGC is there any reason why you couldn’t use a 1k/22k or a 620R/20k (for higher gain) resistor combination instead of the 10k/220k combination you specify? Would you need to change the size of the 4.7uf input capacitor if you did use the lower value resistor combinations?

Because the combination of the small resistors,will reduce the input impedance.then the amp input should be driven by a low impedance source such as an op amp or buffer.here is some discuss:
url, http://www.diyaudio.com/forums/showthread.php?postid=322850#post322850

BTW,for a small resistors 3886 igc,
P-A has a wonderful design 😉the famous industry QRP-02 gainclone.
url, http://home.swipnet.se/~w-50719/hifi/qrp02/index.html

Out of curiosity what is the cost of the heatsinks, size, and what do they weight? Do you know what shipping would be to the states? I would like to get some balanced line driver and regulator boards (if still available) and could use the heatsinks if not too expensive.

the price is $3USD per one,80x138x40(mm).the weight is 0.8kg(approx)...
YGPM🙂

digi

 

[digi01]

the picture reveal another assembly way,the liner regulator is installed on a aluminium chassis.and the diodes is shifted by a international rectifier.

 

[digi01]

sch for this set up:http://www.diyaudio.com/forums/showthread.php?postid=526349#post526349

 

[Vuamp2]

sch for this set up:http://www.diyaudio.com/forums/showthread.php?postid=526349#post526349

Gigi01,

Any recommendation for people with Center tap secondry instead of dual secondary output pair Transfomr?

 

[digi01]

to Vuamp2,
i c,then you have to use the unregulator solution.because NSC is not offer a passive regulator chip with high current output.

edit,mistake modify.

 

[Aunkst]

I soldered up 2 of my four today. I built these two on the cheap to use with the computer. they sound great. no hum. I am happy.

I will keep updating as I put them into some cases.