Hi,
I have this amp over 10 years, recently I notice the power output from it is getting weaker and weaker. I use to turn up only 30% last time for a seal box IDQ 12" , now I need to turn the gain up to 70% for same sound level.
I am not a qualify electrician but some simple job of soldering and replace component is not a problem for me.
Do anyone face similar problem before? If replace all those old cap will fix the problem?
Thanks.
I have this amp over 10 years, recently I notice the power output from it is getting weaker and weaker. I use to turn up only 30% last time for a seal box IDQ 12" , now I need to turn the gain up to 70% for same sound level.
I am not a qualify electrician but some simple job of soldering and replace component is not a problem for me.
Do anyone face similar problem before? If replace all those old cap will fix the problem?
Thanks.
Check the rail voltages first...compare with the good one, it it's the same no need to change caps.
if not maybe the gain knob became deteriorated...
Did anything change in your system in that ten year period or more recently??
As for weather or not the amp needs caps, I suggest that you visually inspect them for swelling and venting.
And try to bear in mind that even the best electrolytic caps made only have a 5 year shelf life, and that lifespan can be less or longer in use depending on abuse level of the design.🙂
Oh and I have the rail spec if you need it...
1moreamp,
Over ten years a lot of thing changes, this is my 3rd car, cable upgrade, new battery, alternator... But all change are meant to give more power to the whole sound system. In the beginning the amp was pair with 2x kickers (spl), later in sq with Shiva than IDQ (last 3 years). The slowly deterioration happen about 2 years ago. I did open it up for visual inspection, not swelling and leaking visible, but can't check under the cap as it is very tight, can't ever slip a paper in. Everything is still original.
Thanks.
Over ten years a lot of thing changes, this is my 3rd car, cable upgrade, new battery, alternator... But all change are meant to give more power to the whole sound system. In the beginning the amp was pair with 2x kickers (spl), later in sq with Shiva than IDQ (last 3 years). The slowly deterioration happen about 2 years ago. I did open it up for visual inspection, not swelling and leaking visible, but can't check under the cap as it is very tight, can't ever slip a paper in. Everything is still original.
Thanks.
Slipping paper underneath lol you have been reading some forum posts haven't you now??? That was one of the old tricks from the phoenix days for the 12 volt side caps to test for leakage.
The main rail caps don't usually leak as much as they lose value. Typically I have seen ten year old cap lose as much as 50% of their rated value in UFD. So say 10,000ufd caps will read as low as 5000ufd and typically around 6500ufd after 10 years of service.
These numbers come for all the MS-2250, and MS2125's and the like that I repaired over the years. I am doubtful the Xenon's fair much better then those great old battleships did.
Any-hoo the real readings you need on old caps is ESR and you will need a ESR meter for that, and a simple cap meter to read their standing value. Plus once you have gone to that much trouble, replacement is not much harder or longer.
The big caps your looking at are rated at 160 VDC and their are both positive and negative rails in this amp so there is a potential above 200+ VDC in there so please be careful tinkering around with the amp turned on or there will be huge sparks on any error you might make.😉
This amp has a 1 to 4 ohm power rating. PG did this by raising and or lowering the internal HV rails by way of a load sensing circuit. This sense circuit can not be bypassed as it is integral to the supply's operation. It will set the rails based on speaker LOAD sensing. So rail spec can vary and with no speaker connected while testing it will be as high as the factory allows, which is about +&- 120 VDC or about a 240 VDC potential.
I would also look for weak or bad solder joints on all the brass colored bus bars they added above the board to carry current. I have seen a number of these solder joints go bad with age and a weak current carrying ability shows up as lost power.
Other then that you might possibly have a sense circuit fault casing the amp to turn on in a lower ohm mode while playing into a higher load this would drop your power off a bit. Its all about that 1 ohm to 4 ohm 1200 watt rating. It does not matter weather at 1 ohm or 4 ohm s the amp will not produce anything but 1200 watts, and actually at 1 ohm its more like 1180 watts according to outside testing.
Hope this helps some....C🙂
The main rail caps don't usually leak as much as they lose value. Typically I have seen ten year old cap lose as much as 50% of their rated value in UFD. So say 10,000ufd caps will read as low as 5000ufd and typically around 6500ufd after 10 years of service.
These numbers come for all the MS-2250, and MS2125's and the like that I repaired over the years. I am doubtful the Xenon's fair much better then those great old battleships did.
Any-hoo the real readings you need on old caps is ESR and you will need a ESR meter for that, and a simple cap meter to read their standing value. Plus once you have gone to that much trouble, replacement is not much harder or longer.
The big caps your looking at are rated at 160 VDC and their are both positive and negative rails in this amp so there is a potential above 200+ VDC in there so please be careful tinkering around with the amp turned on or there will be huge sparks on any error you might make.😉
This amp has a 1 to 4 ohm power rating. PG did this by raising and or lowering the internal HV rails by way of a load sensing circuit. This sense circuit can not be bypassed as it is integral to the supply's operation. It will set the rails based on speaker LOAD sensing. So rail spec can vary and with no speaker connected while testing it will be as high as the factory allows, which is about +&- 120 VDC or about a 240 VDC potential.
I would also look for weak or bad solder joints on all the brass colored bus bars they added above the board to carry current. I have seen a number of these solder joints go bad with age and a weak current carrying ability shows up as lost power.
Other then that you might possibly have a sense circuit fault casing the amp to turn on in a lower ohm mode while playing into a higher load this would drop your power off a bit. Its all about that 1 ohm to 4 ohm 1200 watt rating. It does not matter weather at 1 ohm or 4 ohm s the amp will not produce anything but 1200 watts, and actually at 1 ohm its more like 1180 watts according to outside testing.
Hope this helps some....C🙂
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