Javier
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Post by Javier on Sept 10, 2013 8:12:27 GMT
If it is of any help, I tested all voltages were OK and that all opamps were working fine in my CHAmp before placing them on the filter board.
The LM4562 are spec'ed to +/-17Vmax so 24V means almost 60% over voltage, do you have any gear on which you could test the opamps?
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Deleted
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Post by Deleted on Sept 10, 2013 8:32:04 GMT
If it is of any help, I tested all voltages were OK and that all opamps were working fine in my CHAmp before placing them on the filter board. The LM4562 are spec'ed to +/-17Vmax so 24V means almost 60% over voltage, do you have any gear on which you could test the opamps? Hi Javier i am sure it is my fault. i already new the psu socket should not have been grounded, but i completely forgot what Frans had told me. all part of the ;earning curve i guess! i am glad i ordered a pre-built Ember now and not the kit. i have just removed the socket from the case and the 4 opamps, as suggested. at my power toggle switch, i have 24v going in, but when i switch the toggle on the voltage disappears completely. is there anything else on the board that i may have goosed? "NO" is the answer i am looking for  could you just confirm these are correct before i order? uk.farnell.com/texas-instruments/lm4562na-nopb/op-amp-audio-dual-hf-8-dip-powerwise/dp/1685366 |
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solderdude
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Post by solderdude on Sept 10, 2013 9:16:58 GMT
If you measure in Ohms setting on the PCB directly between + and - (ground connection must be open) and measure in both directions (no power and no wiring connected) what values do you get in both directions ? If is very low (a few Ohms) desolder the TLE2426, it may have been shorted. it's the small transistor alike part IC1. It should be able to handle a shorted output (is what basically happened) If readings are still the same new tips will need to be posted. I am guessing the TLE may have shorted. In that case it is possible the opamps are still O.K. do NOT insert the opamps till a +/-12V has been confirmed to be present with a working TLE2426 in place. TLE2426: uk.farnell.com/texas-instruments/tle2426clpe3/virtual-ground-reference-2426/dp/1207287Also possible you did something wrong with a power LED or such so just check the PCB alone. When you can't figure it out and have skype PM me, and I will talk you through it (in the evening only) if need be. To remove the TLE put a big blob of solder on all 3 pins and heat it. When solder flows GENTLY pull out the part. If you have desolder litze clean out the pads. If you don't have this but do have compressed air (in a can or otherwise) you can use this too. Make the solder flow and 'blast' the solder out of the hole. beware of splatter which is HOT and check the underside of the PCB for small drops of solder. |
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Deleted
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Post by Deleted on Sept 10, 2013 10:10:55 GMT
If you measure in Ohms setting on the PCB directly between + and - (ground connection must be open) and measure in both directions (no power and no wiring connected) what values do you get in both directions ? If is very low (a few Ohms) desolder the TLE2426, it may have been shorted. it's the small transistor alike part IC1. It should be able to handle a shorted output (is what basically happened) If readings are still the same new tips will need to be posted. I am guessing the TLE may have shorted. In that case it is possible the opamps are still O.K. do NOT insert the opamps till a +/-12V has been confirmed to be present with a working TLE2426 in place. TLE2426: uk.farnell.com/texas-instruments/tle2426clpe3/virtual-ground-reference-2426/dp/1207287Also possible you did something wrong with a power LED or such so just check the PCB alone. When you can't figure it out and have skype PM me, and I will talk you through it (in the evening only) if need be. To remove the TLE put a big blob of solder on all 3 pins and heat it. When solder flows GENTLY pull out the part. If you have desolder litze clean out the pads. If you don't have this but do have compressed air (in a can or otherwise) you can use this too. Make the solder flow and 'blast' the solder out of the hole. beware of splatter which is HOT and check the underside of the PCB for small drops of solder. Frans looks like you were right about the TLE. 27 ohm both ways while fitted, open circuit when removed. i will order a replacement from farnell, i guess it will be worth trying again when new TLE and power socket are fitted (and volts tested as you explained already)? thanks for your help. will let you know how it goes. gonna get a tin of compressed air now. |
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solderdude
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Post by solderdude on Sept 10, 2013 10:46:44 GMT
Sometimes it already is enough to blow forcefully through a straw.
Just be sure the solder is melted properly through and through.
Another way that works well is heat the solder till it flows and 'tap' the PCB on a table or something.
When you fitted the new one connect the power supply WITHOUT the opamps and check if you have +/- 12V (black lead on ground, red lead on + and -.
There you should see +/- 12V.
Do not worry if it is a few % off between + and -.
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Deleted
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Post by Deleted on Sept 10, 2013 13:38:01 GMT
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Deleted
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Post by Deleted on Sept 12, 2013 15:28:40 GMT
"these e-bay sockets look nice."
socket came today. they do look better than the one i had previously and also the plug is a tighter fit.
fitted it earlier and now the led's work, where as they did not before.
just waiting on the rail splitter now, and fingers crossed the opamps will be ok.
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Deleted
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Post by Deleted on Sept 20, 2013 18:23:01 GMT
got the rail splitter at long last, so hopefully Sunday i will finish my filter.
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Deleted
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Post by Deleted on Sept 21, 2013 20:17:58 GMT
Frans
what would be your recommended pot settings for my filter? (lcd2r2)
thanks
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solderdude
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Post by solderdude on Sept 21, 2013 21:11:50 GMT
Start with fully counter clockwise (so all the way to the left).
If you like a little bit more highs you can turn it up a bit.
The LCD2 should become much less dark sounding regardless of the position of the potmeter.
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Deleted
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Post by Deleted on Sept 22, 2013 12:31:48 GMT
oh bo...x !!
fitted the rail splitter, voltages were fine +12v and -12v.
fitted the opamps, connected to sources and amp. switched on and nothing happens.
no volt readings.
removed opamps and voltages have returned, so i guess i must have goosed the opamps?
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Deleted
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Post by Deleted on Sept 22, 2013 16:07:22 GMT
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Javier
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Post by Javier on Sept 22, 2013 16:54:06 GMT
Yes, that is the one Simon.
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solderdude
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Post by solderdude on Sept 22, 2013 16:56:09 GMT
Very possible you fried the opamps but was hoping the TLE2426 may have 'protected' the opamps by failing first.
The opamps are correct.
4 Opamps won't bring you near their minimum order price.
One option you have is try each opamp you have individually (so one at a time).
With a bit of luck one failed first and protected the other 3.
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Deleted
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Post by Deleted on Sept 22, 2013 17:22:26 GMT
thanks guys.
i have managed to find other items on farnells that i could now get to bulk out the order.
i bought a labelling machine off ebay to label the filter enclosure, so i could order some batteries for that (it takes 6).
it also can be run from an external psu, so i may go for one of them instead.
its turned into a bit of a saga, this filter. i have to confess i am "more at home" with a spanner or hammer in my hand ,than a soldering iron.
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