I've finally got the itch to work on my old Orion 2150gx. The rail caps in my particular amp are not defective but they appear to have been subjected to extreme heat. I am having a heck of a time trying to source the axial 50 volt 3300 microfarad caps I need with a 105 celsius rating. 85 celsius rated caps are easy to come by but i'd really like to bump them up to last longer in the heat this amp is bound to produce. Other than the fact that it would look odd is there any issues with taking identically rated radial caps and laying them on their side in place of the axials?
As always, I suggest using components as close to the originals as possible. If the originals were 85C components and survived for 20+ years, it's unlikely that they need to be upgraded.
The condition of the shrink wrap isn't necessarily a good indicator of the condition of the capacitor. I've removed and checked a lot of these axial capacitors and most were well within tolerance and passed all tests my LC tester could perform. These are typically high quality capacitors with good seals so the capacitors maintain their original specs (within tolerance) for a long time.
These are likely on the secondary and will produce very little heat themselves. The amp shuts down at ~80c so there is very little chance of them seeing anything greater than their 85C rating.
Now to answer your question. You can use radial capacitors and extend the leads but it will (slightly) change the performance of the capacitor. The main difference is likely to be the impedance at high frequencies. The effective ESR will also increase slightly. None of these are likely to make an audible difference but you should be aware that, all else being equal, an axial cap with short leads would likely be better than a radial cap with extended leads.
The condition of the shrink wrap isn't necessarily a good indicator of the condition of the capacitor. I've removed and checked a lot of these axial capacitors and most were well within tolerance and passed all tests my LC tester could perform. These are typically high quality capacitors with good seals so the capacitors maintain their original specs (within tolerance) for a long time.
These are likely on the secondary and will produce very little heat themselves. The amp shuts down at ~80c so there is very little chance of them seeing anything greater than their 85C rating.
Now to answer your question. You can use radial capacitors and extend the leads but it will (slightly) change the performance of the capacitor. The main difference is likely to be the impedance at high frequencies. The effective ESR will also increase slightly. None of these are likely to make an audible difference but you should be aware that, all else being equal, an axial cap with short leads would likely be better than a radial cap with extended leads.
If i am reading this right you are saying the ones in the amp are most likely good. That would be great because its just one less thing for me to buy for this repair. The shrink wrap on the caps has indeed shrunk to the point where it no longer covers the ends of the caps. The caps are not leaking or bulging by any means though. Or were you simply saying that 105c caps were not a necessity in this application and new 85c caps would be suitable as a replacement. Would it be worthwhile to upgrade the power supply input caps to 105c? Do these caps typically see higher temps than the rail caps?
The original caps are likely still good.
105C caps are not likely needed and if replacements are needed, good quality 85C caps would be suitable.
The power supply primary caps (across B+ and ground) often run much hotter than the secondary capacitors and 105C caps are needed in some amplifiers (I don't know if they're needed in this amp). If the primary side caps are within tolerance, there's no reason to replace them.
105C caps are not likely needed and if replacements are needed, good quality 85C caps would be suitable.
The power supply primary caps (across B+ and ground) often run much hotter than the secondary capacitors and 105C caps are needed in some amplifiers (I don't know if they're needed in this amp). If the primary side caps are within tolerance, there's no reason to replace them.
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