I'll have a look during this long ongoing week end, I should have some spare parts I didn't plan to use soon
Hello Chris!
Well I finally am finding the time to start the project...I finished up my new workplace in my garage!
Good LED lights and a solid workbench!
I have been practicing removing and re-soldering a few diodes on an old ethernet board I had not in use....used the solder paste and YIHUA 898D hot air gun to re-solder...watching the solder melt is neat!!
Trying to figure out what the hot air gun temp should be so I wont burn the small chips up. Its a variable with the type of tip you use and distance from the board etc..so a little more practice for me.
I will post some pix once I get going .
Alex
Well I finally am finding the time to start the project...I finished up my new workplace in my garage!
Good LED lights and a solid workbench!
I have been practicing removing and re-soldering a few diodes on an old ethernet board I had not in use....used the solder paste and YIHUA 898D hot air gun to re-solder...watching the solder melt is neat!!
Trying to figure out what the hot air gun temp should be so I wont burn the small chips up. Its a variable with the type of tip you use and distance from the board etc..so a little more practice for me.
I will post some pix once I get going .
Alex
All the IC's are down via the hot air gun method...look good, checked for shorts with a meter...had to remove one via solder wick...looks better in person than in pix...sorry for the not so high quality pix!!
This is my new workspace, in the garage...the LED light overhead helps with seeing stuff....the head magnifier is a blessing as well!!
The hardest part is getting the solder paste down across the small pads and understanding how much is really needed.
Not much at all!!!
I am still missing the Blue LED from Farnell but will complete the install and wait for the LED...suppossed to be in June 26th!! I might just get a different color...I think digi key has green ones available.
Alex
This is my new workspace, in the garage...the LED light overhead helps with seeing stuff....the head magnifier is a blessing as well!!
The hardest part is getting the solder paste down across the small pads and understanding how much is really needed.
Not much at all!!!
I am still missing the Blue LED from Farnell but will complete the install and wait for the LED...suppossed to be in June 26th!! I might just get a different color...I think digi key has green ones available.
Alex
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Well its all soldered up and except for the Blue LED its ready for testing.....just have to get the nerve to power it up!! LOL.
The solder paste helps installing multiple 805 parts very nice and easy....I tacked paste on a whole row of parts, set each part in the paste carefully and then hot air'd the entire row, watching the paste turn into molten solder, nice and shiney!
It took awhile to figure out the hot air gun temp and the air flow so the parts were not moved in the hot air process.
I also quickly applied some alcohol right after the hot air process quickly to cool down the parts and board. I measured several parts and they seem ok.
Alex
The solder paste helps installing multiple 805 parts very nice and easy....I tacked paste on a whole row of parts, set each part in the paste carefully and then hot air'd the entire row, watching the paste turn into molten solder, nice and shiney!
It took awhile to figure out the hot air gun temp and the air flow so the parts were not moved in the hot air process.
I also quickly applied some alcohol right after the hot air process quickly to cool down the parts and board. I measured several parts and they seem ok.
Alex
Attachments
![WP_20170526_13_32_59_Pro[13088].jpg](/community/data/attachments/556/556893-260e8e925c15a384f9ae6eea904130bc.jpg)
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Ok, connected the 18vdc, 4.5 amp dc supply....and the +5 and -5 are fine...
It WORKS!! First time!! Yeah!
I will give a listen over the next few days and let you know my opinion on how it sounds and how it compares to my several other head amps....
Its such a good feeling to have it work the first time!!..
Seems dead silent, no hum present at full volume etc..
Nice job Chris....this makes me feel more confident with the smaller parts and the hot air
gun tool.
Alex
It WORKS!! First time!! Yeah!
I will give a listen over the next few days and let you know my opinion on how it sounds and how it compares to my several other head amps....
Its such a good feeling to have it work the first time!!..
Seems dead silent, no hum present at full volume etc..
Nice job Chris....this makes me feel more confident with the smaller parts and the hot air
gun tool.
Alex
Congrats
Congrats Alex !
Up and running at the first power up !, it's not always this way !
It's very pleasant to have a little project and pcb used on another part of the globe...
Could you measure voltage across the 7.5R (R5), it 'll give us idle current.
If you running a 18V supply, watch temp of 7805 when playing loud, it may be hot but nothing anormal.
Congrats Alex !
Up and running at the first power up !, it's not always this way !
It's very pleasant to have a little project and pcb used on another part of the globe...
Could you measure voltage across the 7.5R (R5), it 'll give us idle current.
If you running a 18V supply, watch temp of 7805 when playing loud, it may be hot but nothing anormal.
Voltage across R5 = .365v
With music playing and my Beyer T1's attached..300 ohm.
I dont notice much happening with the X-feed switch...I assume the middle position is "no-x-feed", down is low and up is "high"?
The 7805 is warm, but I can touch it with no issue, I will put a thermocouple on it and measure later.
Alex
With music playing and my Beyer T1's attached..300 ohm.
I dont notice much happening with the X-feed switch...I assume the middle position is "no-x-feed", down is low and up is "high"?
The 7805 is warm, but I can touch it with no issue, I will put a thermocouple on it and measure later.
Alex
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Ok, you certainly won't need a heatsink. I got it very hot while testing the amp with 16R load at full power, but it's not a common use case.
Most of my cans are 250/300 ohms, one is 50 or so..
and we arent playing sine waves!!
Its still amazing on how these small chips with the paste work so well with the hot air gun!
I was really wondering if I was going to burn them up via thermal damage!
One thing I have noticed is turning off the amp while music is playing or not there is a small but noticeable turn off transient...a very small, mild pop sound, not really a pop but a mild thump...nothing that will hurt anything...turn on is pretty instant. no pop or thump etc..
Alex
and we arent playing sine waves!!
Its still amazing on how these small chips with the paste work so well with the hot air gun!
I was really wondering if I was going to burn them up via thermal damage!
One thing I have noticed is turning off the amp while music is playing or not there is a small but noticeable turn off transient...a very small, mild pop sound, not really a pop but a mild thump...nothing that will hurt anything...turn on is pretty instant. no pop or thump etc..
Alex
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