So Im looking into buying a broken Diamond D7104. I am no electronics engineer.. but I know a guy whose got a ton of experience in the field and is OK with taking a look at it.
I have found 2 of these.
1- Is missing an inductor (what my buddy called it) inside the unit, and is missing 2 of the 6 caps inside of it. It powers on just fine, but only 1 of the 4 channels is working.
2- Hasnt been touched as far as I can tell, but from what little info I have on it when powered on the red power light flickers on and off.. and obviously no sound.
Any ideas as to what could be wrong with either? Especially the first one.
I have found 2 of these.
1- Is missing an inductor (what my buddy called it) inside the unit, and is missing 2 of the 6 caps inside of it. It powers on just fine, but only 1 of the 4 channels is working.
2- Hasnt been touched as far as I can tell, but from what little info I have on it when powered on the red power light flickers on and off.. and obviously no sound.
Any ideas as to what could be wrong with either? Especially the first one.
1: These amps had problems with the inductor shorting out. It may have been pulled by someone prior to your ownership. Its a very common issue with Diamond/Esoteric amps of this series. A suitable replacement will have to be hand made most likely for the amp to be original and as intended....
2: the second amp could have lots of possible reasons for not powering on. The red led flickering on and off sounds like the internal protection circuitry shutting the amp down after it detects issues inside the amp. but this is just a guess without any internal pics of the amp to view, and or hands on diagnosis of its symptoms...
Hand made? That doesnt sound like fun. Can they not be bought close to the original quality?
That would make sense though. I told my buddy it was missing an inductor and heres what he said.
"The only way that thing, could have come loose is if one of the outputs shorted and pulled a ton of current, heating up the solder joints and then it just fell out, I've seen that before. The missing Caps are odd, either they were never installed, because some amps are the same for several models so they just don't put all of the parts in, or someone has had it open, impossible to tell without looking at the solder joints first hand."
The guy who has the amp now has never opened it, but he bought it from someone else. More than likely, the caps have been missing from a long time ago, but the inductor coming off may be new. It is still bouncing around inside the amp.
That would make sense. The guy told me that he is going off memory that is whats wrong with it.. he didnt check first hand, and he said he wont because hes selling it as is or for parts.
My EE buddy said neither would be easier to fix than the other, especially without being able to diagnose them on hand.. so its a matter of which I get cheapest. I am leaning towards the one with the screwed up power supply/short.
How do you keep the inductor from shorting out? I dont want to have this amp fixed and it blow up on me later with a common issue.
I have seen inductors break there connections to the board before but usually its just one of the connections not all of them, and usually its due to excessive shock and vibration.
In this case yours would have four connections if its the toroid filter for both rails, they have two ins and two outs. They short due to lose windings and the insulation scuffs off the wires and they short against each other or the core itself. Either way its a rewind or replace to repair in most cases. If your lucky you might find the short and be able to clear it with some simple insulating materials. But this is only sometimes.
A Ebay seller had dozens of these old boards he was selling and Patrick of robotunderground on Ebay bought them all. So maybe he can sell you spare parts since these are custom designed for each amp and are a manufacturer only part. Its either that or try to save the toroid to rewind to spec.
The toroid issue might end up be the hardest to deal with due to lack of available parts and design info from the manufacturer. The amp might run without the filter but its was there most likely for design reasons to improve power supply noise issues and overall SQ of the amp.
Without pictures of the amp we are all dealing with arbitrary ideas here, and basically just guessing as to what is really going on with your parts only amp buys. You might want to hold off on buying into unknowns like this especially since your relying on others to be able to repair these unknown issues.
Oh for the toroid to have melted off the board the board would likely be so damaged as to not be able to repair the board let alone the toroid. You really need pictures of what you getting into before this becomes a money sink of no returns. Caveat Emptor < buyer beware >
In this case yours would have four connections if its the toroid filter for both rails, they have two ins and two outs. They short due to lose windings and the insulation scuffs off the wires and they short against each other or the core itself. Either way its a rewind or replace to repair in most cases. If your lucky you might find the short and be able to clear it with some simple insulating materials. But this is only sometimes.
A Ebay seller had dozens of these old boards he was selling and Patrick of robotunderground on Ebay bought them all. So maybe he can sell you spare parts since these are custom designed for each amp and are a manufacturer only part. Its either that or try to save the toroid to rewind to spec.
The toroid issue might end up be the hardest to deal with due to lack of available parts and design info from the manufacturer. The amp might run without the filter but its was there most likely for design reasons to improve power supply noise issues and overall SQ of the amp.
Without pictures of the amp we are all dealing with arbitrary ideas here, and basically just guessing as to what is really going on with your parts only amp buys. You might want to hold off on buying into unknowns like this especially since your relying on others to be able to repair these unknown issues.
Oh for the toroid to have melted off the board the board would likely be so damaged as to not be able to repair the board let alone the toroid. You really need pictures of what you getting into before this becomes a money sink of no returns. Caveat Emptor < buyer beware >
An externally hosted image should be here but it was not working when we last tested it.
Here is a picture of the amp thats missing the inductor and the 2 caps. I know that doesnt do much good.. but I dont have it on hand.
I have found a total of 4 Diamond D7 amps that need repair. 2 D7104s, a D7152, and a D7402.
saw those amps, but not impressed on the price. i wrote the one missing the inductor and caps off as being unsuccessfully messed with, not that anything has fallen out. might believe the cap would break off from extreme vibration, but not the inductor. wondering if he still even has the inductor. kind of hard to re-wrap thin air
Ok I see that one of the mylar input caps for one of the channels is missing. See the large metal rack in the middle there are supposed to be four of those large rectangular mylar caps there, one is missing. no biggy there but it does need to be replaced.
As for the two missing rail caps, I am not sure as my memory is faded now about these but it would not hurt to replace all of those and include two extras to fill the empty spaces.
The large toroid I was talking about is in plain site between those caps. So what ever is broken off and bouncing around inside is probably not a toroid as this amp only had two of them and I see both of them in the picture where they belong. The larger one in between the caps is the big failure item I saw on all of those boards that were sold on ebay a couple years ago now.
So thanks for the picture it helps bunches. But what I see does not match your description in a few places. This amp is fairly old now so cap replacement is not too unexpected with age and use. The missing Mylar in the middle is likely the part bouncing around inside the amp and they are fairly common to come by since PPI used the same cap in their amps. in fact I was once told that these amps were designed by X PPI engineers after PPI went under so similarities will exist between the two different amps.
I can't attest to its repair-ability as I am not the tech working on it but your EE buddy might find it feasible to bring her back to life for reasonable efforts and moneys. ...hope some of this is useful and helpful...
As for the two missing rail caps, I am not sure as my memory is faded now about these but it would not hurt to replace all of those and include two extras to fill the empty spaces.
The large toroid I was talking about is in plain site between those caps. So what ever is broken off and bouncing around inside is probably not a toroid as this amp only had two of them and I see both of them in the picture where they belong. The larger one in between the caps is the big failure item I saw on all of those boards that were sold on ebay a couple years ago now.
So thanks for the picture it helps bunches. But what I see does not match your description in a few places. This amp is fairly old now so cap replacement is not too unexpected with age and use. The missing Mylar in the middle is likely the part bouncing around inside the amp and they are fairly common to come by since PPI used the same cap in their amps. in fact I was once told that these amps were designed by X PPI engineers after PPI went under so similarities will exist between the two different amps.
I can't attest to its repair-ability as I am not the tech working on it but your EE buddy might find it feasible to bring her back to life for reasonable efforts and moneys. ...hope some of this is useful and helpful...
A simple list of common failures I found on these back in the day....
1: Shorted dual filter toroid, and blown power supply caused by shorted toroid
2: Broken thru hole connections on the filter boards up front where the controls are placed.
3: Blown channels, outputs and drivers mostly
4: Bad solder joints on the buss bars used in the power supply, and that cage in the middle is a common ground buss bar for the audio channels so its a must look at to check its integrity of solder connections.
5: failed fans and drivers for the fans and the temp control system for the fans.
I am sure there could possibly be other issues but these top my list of suspects from my experience working on these long ago.
1: Shorted dual filter toroid, and blown power supply caused by shorted toroid
2: Broken thru hole connections on the filter boards up front where the controls are placed.
3: Blown channels, outputs and drivers mostly
4: Bad solder joints on the buss bars used in the power supply, and that cage in the middle is a common ground buss bar for the audio channels so its a must look at to check its integrity of solder connections.
5: failed fans and drivers for the fans and the temp control system for the fans.
I am sure there could possibly be other issues but these top my list of suspects from my experience working on these long ago.
Ok I see that one of the mylar input caps for one of the channels is missing. See the large metal rack in the middle there are supposed to be four of those large rectangular mylar caps there, one is missing. no biggy there but it does need to be replaced.
As for the two missing rail caps, I am not sure as my memory is faded now about these but it would not hurt to replace all of those and include two extras to fill the empty spaces.
The large toroid I was talking about is in plain site between those caps. So what ever is broken off and bouncing around inside is probably not a toroid as this amp only had two of them and I see both of them in the picture where they belong. The larger one in between the caps is the big failure item I saw on all of those boards that were sold on ebay a couple years ago now.
So thanks for the picture it helps bunches. But what I see does not match your description in a few places. This amp is fairly old now so cap replacement is not too unexpected with age and use. The missing Mylar in the middle is likely the part bouncing around inside the amp and they are fairly common to come by since PPI used the same cap in their amps. in fact I was once told that these amps were designed by X PPI engineers after PPI went under so similarities will exist between the two different amps.
I can't attest to its repair-ability as I am not the tech working on it but your EE buddy might find it feasible to bring her back to life for reasonable efforts and moneys. ...hope some of this is useful and helpful...
You guys are great.
It sounds like I was using the wrong term for the piece that is missing. The little red thing, maybe I shouldve stuck to that description instead of getting all fancy.
So there are actually 3 missing caps.. 2 over by the torroid, and the one in the rectangle.. but all 3 of these missing caps wouldnt cause the issue?
Heres a dumb question. If the amp still works on the 1 channel, you would assume the power supply is OK, right? If the other 3 channels arent working, you would assume it has blown outputs on those 3 channels, right?
What exactly are "blown outputs"? I mean what part of the part are people referring to when they say outputs?
Anyone know what these amps are worth in repaired working condition?
You can't see the outputs as they are clamped to the sink inside on the walls of the amp. This amp has SMD and thru hole construction you will likely find burnt open SMD resistors in all the bad channels. pennies to fix, a pain to find at least for me as I have vision problems. It will take a younger persons eye or a good mag lens light to service the amp.
You should ask your EE friend to explain some of this to you as I am sure his location close to you will prevent some very long diatribes from being posted here on the technology as a whole. He will likely explain it in better depth and detail that a simple forum page answer can.
You could check the blue book of car audio for value. Its a fancy gold finished door stop to me until it repaired properly..lol...and where I live it will cost you to throw it away unless you find a free recyclers to handle it for you.
You should ask your EE friend to explain some of this to you as I am sure his location close to you will prevent some very long diatribes from being posted here on the technology as a whole. He will likely explain it in better depth and detail that a simple forum page answer can.
You could check the blue book of car audio for value. Its a fancy gold finished door stop to me until it repaired properly..lol...and where I live it will cost you to throw it away unless you find a free recyclers to handle it for you.
I wanted to update this. My buddy got it, reinstalled the coupling cap and put a few caps in place of the missing caps.. and its working great!
To try and make sure it stays that way, he recapped the whole thing for me. 50-60+ caps IIRC.. he actually upgraded a lot of the caps as well for more storage.
"You can see the bus bars over the caps, really stupid design, and they all used to be 470uF sized, the same as the 2 that are under each bar which still are 470uF, new, but same size. I went with 1000uf for the rest of them since the room was there and with car amps and capacitance the more the better, to a point. That changed the storage there from 9400uF to 16940uF, or 1.8 times larger. These are the input DeCoupling, they do the same thing adding in some huge Farad cap do, just not to that extent, but increasing the value never hurts.
The 6 large caps there, technically 3 when it showed up here since they were all broken off, were originally 1000uF each, and are now 2200uF, so an increase from 6000uF to 13200uF, or 2.2 times larger there. Those are the DeCoupling caps for the higher voltage the power supply makes for the amplification."
Car Audio pictures by RDCXBG - Photobucket
Hes got the whole thing back together and its working great. Hopefully he will ship it out either tomorrow or Monday. Excited to see if I can audibly hear a difference over my small Kenwood KAC 8405 that Im using right now.
To try and make sure it stays that way, he recapped the whole thing for me. 50-60+ caps IIRC.. he actually upgraded a lot of the caps as well for more storage.
"You can see the bus bars over the caps, really stupid design, and they all used to be 470uF sized, the same as the 2 that are under each bar which still are 470uF, new, but same size. I went with 1000uf for the rest of them since the room was there and with car amps and capacitance the more the better, to a point. That changed the storage there from 9400uF to 16940uF, or 1.8 times larger. These are the input DeCoupling, they do the same thing adding in some huge Farad cap do, just not to that extent, but increasing the value never hurts.
The 6 large caps there, technically 3 when it showed up here since they were all broken off, were originally 1000uF each, and are now 2200uF, so an increase from 6000uF to 13200uF, or 2.2 times larger there. Those are the DeCoupling caps for the higher voltage the power supply makes for the amplification."
Car Audio pictures by RDCXBG - Photobucket
Hes got the whole thing back together and its working great. Hopefully he will ship it out either tomorrow or Monday. Excited to see if I can audibly hear a difference over my small Kenwood KAC 8405 that Im using right now.
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