Over the weekend I used hot air to set up the power supply elements on 2 - D3's. A little touch up with a fine tip iron. I'm using a single Salas Ultra BiB v1.3 positive reg for the floating supply & a Salas Reflector-D for the 5 volts.
One of them is spot on with -15.02v, -5.02v & +4.92v. The other I have -10v, -0v & +5v.
I ordered enough parts to fill 2 boards and rounded up to 10 when ordering on most of them, so I do have a spare part or two. Here are photos of front & back, anybody see anything that will cause my -5v reg to fail? Any help is very much appreciated.
Aguaazul
Shared album - Blue Water - Google Photos
Shared album - Blue Water - Google Photos
One of them is spot on with -15.02v, -5.02v & +4.92v. The other I have -10v, -0v & +5v.
I ordered enough parts to fill 2 boards and rounded up to 10 when ordering on most of them, so I do have a spare part or two. Here are photos of front & back, anybody see anything that will cause my -5v reg to fail? Any help is very much appreciated.
Aguaazul
Shared album - Blue Water - Google Photos
Shared album - Blue Water - Google Photos
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Yep, I soldered 3 resistors together, plug that leg into ground, then the other end of the resistors go to the voltage pins, I'm measuring by touching the resistor legs.
Shared album - Blue Water - Google Photos
It's good to send out reminders though!
Aguaazul
Hi Aguaazul,
From looking at your photos I think it would help to re-flow all your solder joints with some flux, in particular there a few areas of solder around X2 that look like they haven't flowed into the joint properly.
Also a voltage of +4.92 is a bit low for the +5 reg - I would re-flow that board too. (edit - this will probably come up to voltage when the poly caps are soldered on.)
From looking at your photos I think it would help to re-flow all your solder joints with some flux, in particular there a few areas of solder around X2 that look like they haven't flowed into the joint properly.
Also a voltage of +4.92 is a bit low for the +5 reg - I would re-flow that board too. (edit - this will probably come up to voltage when the poly caps are soldered on.)
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Hey Ryan,
Thanks for your help.
I own 4 DC3 boards. Two of them have decent step 1 voltages, enough to move on.
Board #1 has -14.996, -4.997 & + 4.996.
Board #2 has -14.999, -5.011 & + 4.993.
Board #3 is messed up (was #1). As I populated it some more, I lost a trace when solder paste bridged some pins on the TDA1541A socket. I attempted to remedy it, still have not given up.
Like you mentioned, once the poly caps get in there, hopefully the voltages come up where they need to be. I've been planning these builds for over a year. The spare time on my hands recently gave me the window to get these built.
After I get these tested & running, (if all is well) I'd like to try a dual board setup. Perhaps a quad board attempt, I have my name on the list for 2 more boards.
I have a smattering of TDA's laying around. TDA1541, & TDA1541A R1 for testing. Some CD players with TDA1541A's inside and 5 NOS TDA1541A's. Still looking for some elusive TDA1541A S1.
In the 1st board I built, the one with no -5 voltage, I had transposed R27 & R29 positions, looking at the schematic, not that that should have really hurt anything in the -5 volt range, but I moved them to their correct positions.
I did re-flow everything in the -5 volt range, no help, then I replaced X2 & Q2 parts, all is well now.
I think you had it pegged with the X2 situation, Q2 I changed just for the heck of it.
I'm getting there. Thanks again!
Aguaazul
Thanks for your help.
I own 4 DC3 boards. Two of them have decent step 1 voltages, enough to move on.
Board #1 has -14.996, -4.997 & + 4.996.
Board #2 has -14.999, -5.011 & + 4.993.
Board #3 is messed up (was #1). As I populated it some more, I lost a trace when solder paste bridged some pins on the TDA1541A socket. I attempted to remedy it, still have not given up.
Like you mentioned, once the poly caps get in there, hopefully the voltages come up where they need to be. I've been planning these builds for over a year. The spare time on my hands recently gave me the window to get these built.
After I get these tested & running, (if all is well) I'd like to try a dual board setup. Perhaps a quad board attempt, I have my name on the list for 2 more boards.
I have a smattering of TDA's laying around. TDA1541, & TDA1541A R1 for testing. Some CD players with TDA1541A's inside and 5 NOS TDA1541A's. Still looking for some elusive TDA1541A S1.
In the 1st board I built, the one with no -5 voltage, I had transposed R27 & R29 positions, looking at the schematic, not that that should have really hurt anything in the -5 volt range, but I moved them to their correct positions.
I did re-flow everything in the -5 volt range, no help, then I replaced X2 & Q2 parts, all is well now.
I think you had it pegged with the X2 situation, Q2 I changed just for the heck of it.
I'm getting there. Thanks again!
Aguaazul
I'm using the built in OP. I'm using a TDA1541 R1 to test. There is a problem then, both sides the lowest it will go is 20mA. Here are photos:
(Open in new window or tab)
When I measure R32 & R33 on the board, they are only 1K Ohm, so I pulled out a fresh one from the package, it's spot on a 2K Ohm.
I forgot to solder the J2. Now it's really off, AOR1 is 77.5mA at the lowest. AOL1 can only get down to 169mA.
Thanks for looking.
Aguaazul
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
(Open in new window or tab)
When I measure R32 & R33 on the board, they are only 1K Ohm, so I pulled out a fresh one from the package, it's spot on a 2K Ohm.
I forgot to solder the J2. Now it's really off, AOR1 is 77.5mA at the lowest. AOL1 can only get down to 169mA.
Thanks for looking.
Aguaazul
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Yup, that was the case for my build also. Once a signal was fed to the dac board the DC offset trimmed right to 0V for both channels
