I have a ADS equalizer with a burnt transformer it has a three wire output with outputs of 13.5v and 61v. Finding a replacement is impossible, can I use two seperate transformers by sharing the same common wire on the output side? Also do I need to use audio transformers?
I would suggest a power supply transformer of the proper VA, Primary and secondary voltages that match the one you are replacing. Audio transformers are for audio signal transformation. It sounds like the failed transformer is custom wound by the manufacturer for that application. You might try them for replacement parts. Hope this helps
Regards,
Brannon
Regards,
Brannon
It may help to know the model of your ADS EQ. Something tells me there is a reason for the old transformer to have burned up.
Sure ADS SS2 MKI I know just enough about electronics to electrocute myself. Not really I can do somethings by building my own speaker crossovers. RC boat electronics etc. I am not sure where to start I have checked for any outer signs of burning of all components sall good and no burn smells. The transformer is toast this I know. I do know how to use all of the meters I have along with my small portable 2 ch. oscilloscope. I can test but I don't know how to trace and isolate something like this.
Mike,
Ixnay makes a good point. If you replace the old transformer with a new one without finding the circuit fault first you'll likely smoke the new one. You could start by looking around the web for a schematic. If none can be found, try contacting the manufacturer assuming they're still in business.
Ixnay makes a good point. If you replace the old transformer with a new one without finding the circuit fault first you'll likely smoke the new one. You could start by looking around the web for a schematic. If none can be found, try contacting the manufacturer assuming they're still in business.
You can try to troubleshooting without a schematic or vendor help but it can be much more difficult. Start looking for the easy things first. Isolate the unit from the mains AC. Validate there is no voltage on the power supply filter capacitors. Does it have a fuse? If its blown, don't just replace it. Look downstream of the fuse and start checking diodes and capacitors with your DMM for shorts and grounds to find the cause. It can seem daunting but you just might get lucky. Hope this helps.
Brannon
Brannon
Sometimes the bad component is actually the transformer. It might be worth trying to power up the device using a dual output bench supply with variable current limiting. If it comes up okay then could be just a bad transformer. Another thing to do might be to check transistors and or power rails for dead shorts with DVM. Visual inspection might also show bulging electrolytic capacitors.
So, you say that the transformer has 13.6 and 61 (maybe you meant 6.1) volt output. Was that labeled somewhere or did you measure that? I know that you said that the transformer is shot so that must mean that there is nothing lighting up or that you have measured 0 voltage somewhere. I just want to know how you came to the conclusion that you did and what you might have or measured so far.
I tested the transformer with the outputs connected then disconnected. no power on either. On the manual it shows power output 13.5v and 61v. The model number of the transformer is a P-100686 that I cannot even crossover with a newer replacement. Here are the specs on the power supply. I hav not measured anything internally yet. I don't know where to begin.
Attachments
Mike,
That screenshot is very helpful. Having said that, you are stating that there is no voltage to be found on either output of the transformer. The mistake that I have made in the past is in not setting my meter to AC when measuring from the transformer. Dc setting of course would be from the output of the power supply itself. I know that you know, yet, I have to ask because of my past experience. Does this EQ have a fuse on the AC line itself? Once we get past that, there will be a good start on those pesky questions behind us that I have stated so far.
I look forward to help from others here as well since I am not a tech, but more of a builder.
That screenshot is very helpful. Having said that, you are stating that there is no voltage to be found on either output of the transformer. The mistake that I have made in the past is in not setting my meter to AC when measuring from the transformer. Dc setting of course would be from the output of the power supply itself. I know that you know, yet, I have to ask because of my past experience. Does this EQ have a fuse on the AC line itself? Once we get past that, there will be a good start on those pesky questions behind us that I have stated so far.
I look forward to help from others here as well since I am not a tech, but more of a builder.
If you buy a new transformer, it will be rating the AC voltage. Rectified and filtered by a capacitor,
that will be 1.4 times higher (square root of 2).
So you need a 40V AC and a 2x9V AC transformer. This will give the voltages you see with an DC voltmeter.
Simpler to get are two transformers, one 2x20V and one 2x9V. Both rated 100mA. You connect the 2x20 in series and have 40V.
As this seems to be a very old device, it is a very good idea to change the mentioned capacitors and diodes. That may cost you less than 10$ extra. The transformers should be about 5$ each. Plus P&P. Calculate. Is the thing worth it? There is still the risk it may have other failing parts... maybe sell it on eBay unrepaired, better than butchered.
If you mail order the transformers, just include the extra parts. You got to find out the right values in uF, but larger does not matter. 63V and 25V are the usual ratings. The diodes should be 1N4002 or the like. So nothing complicated, just very usual parts.
Even if you change the transformer and the caps and diodes, measure the voltage when you power it on. The transformer can tollerate about 10-20 seconds of a short (hopefully). If the AC or DC voltage is lower than expected, there is a short somewhere- these voltages only fuel further stabilizing cirquits! This needs attention!
If you post good pictures of the clean PCB, some here may have other ideas that help you.
Good luck.
that will be 1.4 times higher (square root of 2).
So you need a 40V AC and a 2x9V AC transformer. This will give the voltages you see with an DC voltmeter.
Simpler to get are two transformers, one 2x20V and one 2x9V. Both rated 100mA. You connect the 2x20 in series and have 40V.
As this seems to be a very old device, it is a very good idea to change the mentioned capacitors and diodes. That may cost you less than 10$ extra. The transformers should be about 5$ each. Plus P&P. Calculate. Is the thing worth it? There is still the risk it may have other failing parts... maybe sell it on eBay unrepaired, better than butchered.
If you mail order the transformers, just include the extra parts. You got to find out the right values in uF, but larger does not matter. 63V and 25V are the usual ratings. The diodes should be 1N4002 or the like. So nothing complicated, just very usual parts.
Even if you change the transformer and the caps and diodes, measure the voltage when you power it on. The transformer can tollerate about 10-20 seconds of a short (hopefully). If the AC or DC voltage is lower than expected, there is a short somewhere- these voltages only fuel further stabilizing cirquits! This needs attention!
If you post good pictures of the clean PCB, some here may have other ideas that help you.
Good luck.
Last edited:
I did check the voltage for AC power, I have uploaded some pics maybe there is something that jumps out at someone. I did visually checked all caps and none are leaking or puffed. Also before taking out the transformer I Cleaned Pots and faders with DetoxIT D5 and then used DetoxIT F5 on the faders.
Attachments
I was so hoping that there was a simple answer for this such as a power fuse. Wouldn't that be nice? You have stated everything that I have asked so far, so we can move on. Without knowing what might have happened downwind in the circuit, the idea of replacing the transformer will 2 replacements may be your best bet.
Then as suggested in previous posts, you can then measure voltages when the unit is powered up again (assuming of course that the replacement transformers get you in the ballpark without adjustment needed in the power circuit). Anyway, you can only go as fast as parts are discovered, needing to be replaced.
I agree with the thinking that many if not all electrolytic capacitors and maybe more components should be replaced without question just due to their age. Even though a cap doesn't 'look bad' it doesn't mean that it isn't, or at least performing below expectation. Wish that a schematic would be available to help us out.
I also look forward to the continued support of those who have experience in this field.
Then as suggested in previous posts, you can then measure voltages when the unit is powered up again (assuming of course that the replacement transformers get you in the ballpark without adjustment needed in the power circuit). Anyway, you can only go as fast as parts are discovered, needing to be replaced.
I agree with the thinking that many if not all electrolytic capacitors and maybe more components should be replaced without question just due to their age. Even though a cap doesn't 'look bad' it doesn't mean that it isn't, or at least performing below expectation. Wish that a schematic would be available to help us out.
I also look forward to the continued support of those who have experience in this field.
I tested every combination as I did with power, Nothing I was a little surprised, I figured I was going to get some type of ohm reading or continuity. 000.0000000000000
You mean that all of the windings do NOT have ohmic continuity?
They all read open circuit on the ohms range? That seems very unlikely.
And when you short the meter leads, the reading is zero?
They all read open circuit on the ohms range? That seems very unlikely.
And when you short the meter leads, the reading is zero?
Last edited: