artarama Posted December 10, 2011 Share Posted December 10, 2011 So I'm diving in to replace the capacitors on my new Luxman R1120 Receiver that has been sitting in someones storage long enough to have spyder webs on the inside. I am replacing many of the capacitors but before I get too far along I need some reasurance. The pyhsical size of the replacement capacitors I have purchased are in some cases much smaller than the original equipment. My question is: If the specifications for Micro Farads & Voltage are correct will a much physically smaller unit function as well as a larger one? Is this just a function of newer manufacturing abilities? I know there are temperature and operating tollerances as well but those specs are acceptable. An example is the original equipment (Nippon Chemi Con)16V, 220 micro Farad cap measures 10mm in diameter and is 20mm tall. The replacement (NTE) is also 16V, 220 micro Farads but is only 6mm in diameter and 11mm tall. (About half the size) None of the original capacitors look bad ie. leaking or domed tops. I don't want to take any steps backward by putting in any lesser, newer equivalents. I kind of feel like I am replacing a big block Chevy with a new "Volt" engine (or is that a battery?) Thanks. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted December 10, 2011 Share Posted December 10, 2011 voltage, capacitance, and the temp rating of the cap has to be considered. if you have the same voltage, same caapacitance, and the same temp rating you are good. For power supply capacitors, going bigger in capacitance is not a problem. For signal capacitors, you need to keep the capacitor values the same. While you are in there, google around on your unit. some vintage gear does well by adding by-pass capacitors along power supply capaciters. Use a solder wick or a solder removel gizmo to remove the old caps and be careful not to overheat the circut trace to much since it can peel off pretty easy. Also becareful on overheating the leads on the new capacitor since excessive heat will damage the capacitor. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted December 10, 2011 Share Posted December 10, 2011 Newer technology has allowed the size of capacitors to be greatly reduced. Whatever you do, make sure that the rated working voltage of the replacements is at least the same as what's in there now. Also, go for the highest ripple current rating for the power supply electrolytic caps that you can find. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted December 10, 2011 Share Posted December 10, 2011 ...I kind of feel like I am replacing a big block Chevy with a new "Volt" engine (or is that a battery?)... It's more like replacing a 1968 Ford 390 ci (335hp) cast iron big block with a 2012 Ford 3.7L (305hp) all aluminum small block. [] Quote Link to comment Share on other sites More sharing options...
artarama Posted December 10, 2011 Author Share Posted December 10, 2011 It's more like replacing a 1968 Ford 390 ci (335hp) cast iron big block with a 2012 Ford 3.7L (305hp) all aluminum small block. This is a much better analogy! Thanks for all the advice. The soldering is going along fine, Solder wick is indespensible, I got a new tip for the iron and I am being very carefull. I have good light and have stripped it down far enough to have good access and working space. When I told my wife my buddies on the Klipsch forum had come through with good advice that the physical size doesn't matter, her response was "that's such a guy thing to say" ! Quote Link to comment Share on other sites More sharing options...
mustang guy Posted December 10, 2011 Share Posted December 10, 2011 It's more like replacing a 1968 Ford 390 ci (335hp) cast iron big block with a 2012 Ford 3.7L (305hp) all aluminum small block. This is a much better analogy! Thanks for all the advice. The soldering is going along fine, Solder wick is indespensible, I got a new tip for the iron and I am being very carefull. I have good light and have stripped it down far enough to have good access and working space. When I told my wife my buddies on the Klipsch forum had come through with good advice that the physical size doesn't matter, her response was "that's such a guy thing to say" ! "Size doesn't matter!" We should make t-shirts. [] BTW, fritz knows a lot more about this topic than I do. Quote Link to comment Share on other sites More sharing options...
Arkytype Posted December 12, 2011 Share Posted December 12, 2011 I recently recapped my McIntosh C504 preamp and C502 amplifier. The smaller physical size of many of the replacement caps was surprising. I did increase the value of the power amp's main filter caps about 30%. speakerfritz wrote: For power supply capacitors, going bigger in capacitance is not a problem. For larger power amps, one needs to be mindful of the inrush current--too much will blow the mains fuse. While it may be tempting to replace say a vintage 30,000 uFD capacitor with one of the same size but double the value, you will probably blow the mains fuse everytime! Lee Quote Link to comment Share on other sites More sharing options...
djk Posted December 12, 2011 Share Posted December 12, 2011 A 30,000µF cap will generally blow a 25A bridge rectifier unless you add inrush current limiting. Quote Link to comment Share on other sites More sharing options...
artarama Posted December 13, 2011 Author Share Posted December 13, 2011 I'm holding to the original values as close as possible, only varying the voltage rating when I have to. So far I have replaced 38 caps on the two main "power boards" but there are at least another 30 - 40 in other places. I am also replacing the 4 power transistors as one is bad. Should I "soldier" on with my soldering or let them go until they actually fail (if that is in my lifetime) ? How about replacing the caps on the phono stage, any risk of changing the sound for the better or worse? I am still enjoying the project, I just don't want to change this unit any more from original than is necessary or prudent. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted December 13, 2011 Share Posted December 13, 2011 I'm holding to the original values as close as possible, only varying the voltage rating when I have to. So far I have replaced 38 caps on the two main "power boards" but there are at least another 30 - 40 in other places. I am also replacing the 4 power transistors as one is bad. Should I "soldier" on with my soldering or let them go until they actually fail (if that is in my lifetime) ? How about replacing the caps on the phono stage, any risk of changing the sound for the better or worse? I am still enjoying the project, I just don't want to change this unit any more from original than is necessary or prudent. Once you start replacing the caps in the tuner sections, a complete realignment will be necessary. So, if you don't have the required test equipment and know how to do this, I'd leave well enough alone. Regarding the phono section, depending on how much capacitor values have changed, the resulting sound after replacement can be different. Whether it will be pleasing or not is indeterminate. The same can be said for the preamp and amp sections also. But, since you're already committed in that part of the circuit, I'd certainly finish the job there. Quote Link to comment Share on other sites More sharing options...
djk Posted December 13, 2011 Share Posted December 13, 2011 "Once you start replacing the caps in the tuner sections, a complete realignment will be necessary" Changing dried out electrolytics will not affect the alignment. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted December 14, 2011 Share Posted December 14, 2011 "Once you start replacing the caps in the tuner sections, a complete realignment will be necessary" Changing dried out electrolytics will not affect the alignment. I didn't look at the schematic for this unit, but if the multiplex section uses discrete components, replacing the electrolytics with those having different values/characteristics can throw things off. Some say it can't happen, but in my experience it has. Quote Link to comment Share on other sites More sharing options...
artarama Posted December 18, 2011 Author Share Posted December 18, 2011 I'm waiting on more capacitors for now. I had hoped to finish this project before I had to "clean-up my mess" for the Holiday's but that is probably not going to happen. I am leaning toward replacing all capacitors since I am so far into it and would like to feel like I did a through job. I can always have someone else align it if needed and in the mean time I have also started to look for a signal generator. I would like to be able to work on all of my equipment start to finish and enjoy learning a new skill. Hopefully the education won't be too expensive, and there is a wealth of experience right here. Thanks tube fanatic and djk! The comment about dried out capacitors has always struck a cord so I decided to open an old one up to have a look. It was in fact the very definition of "dried out". Almost powdery, nothing that could remotely be described as "moist" or "maliable". I still am not sure what sonic affect that would have but it was very dry. FYI I have also stumbled on several actual lectures on YouTube from MIT and Stanford. You can actually audit classes on electronics, solid state chemestry etc. pretty cool. Way over my head for now, but some of it sticks. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted December 18, 2011 Share Posted December 18, 2011 Doing a complete tuner section alignment on a receiver like this is not something that should be attempted if you don't have the experience; it's much too easy to mess things up! At the very least you will need an AM sweep generator, an FM stereo signal generator with calibrated output, and an oscilloscope. For educational purposes, it would be better to find an old solid state mono tuner and play around with that. There are probably some online tutorials on the procedure to be followed. In any event, good luck, and don't hesitate to ask if you need any more advice. Quote Link to comment Share on other sites More sharing options...
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