This is one of the few amps that I recommend replacing all of the capacitors. The rail caps are the least likely to fail but if you're replacing the rest, you may as well replace those.
When cleaning the pads for the small caps, a fiberglass scratch pen works very well. If you buy one, get refills for it. Watch for corroded vias on caps where there is a trace on the top side of the board. If the via is gone, you'll have to install the cap a bit off of the board to allow you to solder to the trace on top.
If you decide to replace the rail caps, use the chipquik. Work it well into the via, straighten the legs of the cap (so they don't tear out the vias) and heat both legs alternately to allow you to pull both legs at once.
When cleaning the pads for the small caps, a fiberglass scratch pen works very well. If you buy one, get refills for it. Watch for corroded vias on caps where there is a trace on the top side of the board. If the via is gone, you'll have to install the cap a bit off of the board to allow you to solder to the trace on top.
If you decide to replace the rail caps, use the chipquik. Work it well into the via, straighten the legs of the cap (so they don't tear out the vias) and heat both legs alternately to allow you to pull both legs at once.
Ok got the amp, amp powers up and produces audio.
The RCA jacks were rusted solid so I replaced them with new ones I have in stock....only because they are the same as a Rockford HD amp.
I also replaced the 2 10uf 35v caps on the input board.
The 25k gain pots are trashed. I have the exact same pots from a Rockford 250m2 but they are 5k.
What would be the result of installing the 5k instead of the 25k for testing purposes and long term use?
I know the value but can anyone give me an idea of the size and or part number for the originals?
The RCA jacks were rusted solid so I replaced them with new ones I have in stock....only because they are the same as a Rockford HD amp.
I also replaced the 2 10uf 35v caps on the input board.
The 25k gain pots are trashed. I have the exact same pots from a Rockford 250m2 but they are 5k.
What would be the result of installing the 5k instead of the 25k for testing purposes and long term use?
I know the value but can anyone give me an idea of the size and or part number for the originals?
I think they're only being used as voltage dividers so I don't think it will doanything other than reducing the input impedance of the amp.
Mouser has Piher 15mm pots but they don't appear to have the correct configuration to allow the original shaft to be used for the 25k pot. The 531-PT15NH-10K may work if the pot is only a voltage divider.
Mouser has Piher 15mm pots but they don't appear to have the correct configuration to allow the original shaft to be used for the 25k pot. The 531-PT15NH-10K may work if the pot is only a voltage divider.
The voltage isn't the issue. The output impedance of the head unit could be but probably isn't an issue.
You could use the correct value and use a screwdriver to adjust the gain. In my opinion, that would be the best option if you can't find the original pots.
What wrong with the originals? If the back has popped out, it can be popped back it. If they're noisy, they can generally be cleaned.
You could use the correct value and use a screwdriver to adjust the gain. In my opinion, that would be the best option if you can't find the original pots.
What wrong with the originals? If the back has popped out, it can be popped back it. If they're noisy, they can generally be cleaned.
The preamp output impedance of the head unit is 50 ohms.
The legs are broke off one pot and one has popped apart.
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