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xrk971 Pocket Class A Headamp GB
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Old 28th January 2017, 07:46 AM   #11
Mituisho is online now Mituisho  Hong Kong
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Join Date: Apr 2015
Location: Hong Kong
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 1 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards
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Old 28th January 2017, 07:51 AM   #12
Morde is offline Morde  Finland
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Join Date: Oct 2014
Default Let's make it 2 pieces... =)

Quote:
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 2 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards

Last edited by Morde; 28th January 2017 at 07:52 AM. Reason: Mituisho was faster than me
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Old 28th January 2017, 08:17 AM   #13
bogde is offline bogde
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Join Date: Aug 2016
Quote:
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 2 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards
bogde - 2 boards
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Old 28th January 2017, 09:07 AM   #14
faltinsen is offline faltinsen
diyAudio Member
 
Join Date: Feb 2015
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 2 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards
bogde - 2 boards
faltinsen - 2 boards
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Old 28th January 2017, 12:34 PM   #15
xrk971 is offline xrk971  United States
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Join Date: Oct 2012
Location: Metro DC area
xrk971 Pocket Class A Headamp GB
Quote:
Originally Posted by xrk971 View Post
Below items are all available from Mouser (circa $20)

Description Part No Qnty
n-channel power MOSFETs ZVN4306GTA 2
n junction JFET BF862 771-BF862-T/R 2
Panasonic OSCON 390uF 20v output caps 20SEPF390M 2
Output cap bypass WIMA 1uF MKS caps MKS2C041001F00KSSD 2
Input bypass Wima 2.2uF MKS caps MKS2B042201F00JSSD 2
Panasonic OSCON 100uF 25v rail caps 20SEP100MX 2
Switchcraft 3.5mm stereo jacks 35RAPC4BV4 2
Alps stereo pot with power switch RK0971221Z05 1


Plus you will need the following 0805 1% metal thin film SMT resistors (qnty):
33R(2), 47R(2), 270R(12), 1k(2), 15k(1), 47k(2), 100k(2), and qnty 4 x 100nF X7R 0812 MLCC bypass caps, and basic 3mm red or green LED.
Please note, I found a typo in the BOM:

SMT resistors should have qnty 4 x 270R and qnty 8 x 470R. Also from previous errata the 100nF X7R caps should be 1206 - but I think if you have 0805, they could be fitted in the same pads.
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Old 28th January 2017, 02:43 PM   #16
Morde is offline Morde  Finland
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Join Date: Oct 2014
I don't get it. By looking at the schematic provided, I can't seem to find where to put the 470R resistors? I even tried to seach through the main design thread... Or is the final schematic not yet published?
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Old 28th January 2017, 02:46 PM   #17
xrk971 is offline xrk971  United States
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Join Date: Oct 2012
Location: Metro DC area
xrk971 Pocket Class A Headamp GB
Sorry I will post schematic soon. The 470R are the qnty 4 in parallel power resistors to give 118ohms or close to 120R. I do this to spread the heat load over a wider surface area to dissipate heat and four 0805 resistors are cheap compared to a larger SMT power resistor.

If you look at the layout you will see four in parallel from mosfet output to ground.

Click the image to open in full size.
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Old 28th January 2017, 06:52 PM   #18
vanofmonks is offline vanofmonks  United States
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Join Date: May 2006
Quote:
Originally Posted by faltinsen View Post
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 2 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards
bogde - 2 boards
faltinsen - 2 boards
vanofmonks - 1 board
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Old 28th January 2017, 11:27 PM   #19
M_Balou is offline M_Balou  Europe
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Join Date: Dec 2005
Location: North of Germany
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 2 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards
bogde - 2 boards
faltinsen - 2 boards
vanofmonks - 1 board
M_Balou - 2 boards
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Old 28th January 2017, 11:44 PM   #20
dwpeterson is offline dwpeterson  United States
diyAudio Member
 
Join Date: Feb 2013
Default One for me please...

Quote:
Originally Posted by M_Balou View Post
xrk971 - 2 boards
pcgab - 2 boards
zman01 - 2 boards
stellarelephant - 2 boards
samoloko - 1 pcb
lui04 - 2 boards
Morde - 2 board
cyteen - 2 boards
funch - 2 boards
syyma - 2 boards
av-trouvaille - 2 boards
Mituisho - 2 boards
bogde - 2 boards
faltinsen - 2 boards
vanofmonks - 1 board
M_Balou - 2 boards
dwpeterson - 1 - one board
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