I looked at Farnell.UK
theres only one 47uf/500V, a more expencive Cornell Dubilier
if you can do with 450V there are more options
but printmounted remember to also look at can size, pin type and spacing
is it hole throug like this http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6997581
or this snap-in http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=4148932
theres only one 47uf/500V, a more expencive Cornell Dubilier
if you can do with 450V there are more options
but printmounted remember to also look at can size, pin type and spacing
is it hole throug like this http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6997581
or this snap-in http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=4148932
Thanks for the help and pointers.
I've found one from Germany rated at 500V that fits the bill and I'll order some other bits from them too to make the postage worthwhile.
Unfortunately I don't yet know enough to say with confidence that the B+ will be sufficiently less than 450V to be able to get away with a 450V rated cap, hence the need for a 500V-rated to cover all bases and avoid things going up in smoke!
Kind regards.
I've found one from Germany rated at 500V that fits the bill and I'll order some other bits from them too to make the postage worthwhile.
Unfortunately I don't yet know enough to say with confidence that the B+ will be sufficiently less than 450V to be able to get away with a 450V rated cap, hence the need for a 500V-rated to cover all bases and avoid things going up in smoke!
Kind regards.
Unfortunately the world wide parts shortage has made 500 volt caps rather hard to find. I was planning to offer a parts kit for the Simple SE but I can't seem to get 500 volt caps from a good supplier either right now. If you are using the 375-0-375 volt power transformer a 450 volt cap is not recommended. The voltage can go over 450 volts during warm up.
As suggested motor run caps rated for 370 VAC mounted off the PC board are an entirely usable solution. I usually recommend the addition of a motor run cap in parallel with C2. The board can be operated without C2 if a 100 uF or larger motor RUN cap is added. Do not use a motor START cap.
A 33 uF or 39 uF cap of 500 volt rating can be used for C1 if you can find those. Axial lead caps can often be used if the negative lead is folded back alongside the can and the assembly is covered with heat shrink.
As suggested motor run caps rated for 370 VAC mounted off the PC board are an entirely usable solution. I usually recommend the addition of a motor run cap in parallel with C2. The board can be operated without C2 if a 100 uF or larger motor RUN cap is added. Do not use a motor START cap.
A 33 uF or 39 uF cap of 500 volt rating can be used for C1 if you can find those. Axial lead caps can often be used if the negative lead is folded back alongside the can and the assembly is covered with heat shrink.
During my hunt I emailed this company below who were very helpful and offered to get me sample of F&T 500V caps to test with a view to a bulk order of around 140 or so to make it worthwhile. I think I must have given the impression I was after a good few rather than just a couple, so after putting him right we took it no further. Maybe of use to you if you can stomach importing them from the UK?
AudioCap: The Audio Capacitor Online Shop
Although I've not any ordered yet, I've pretty much settled on these below, also from Germany:
Tube-Town Online-Store - JJ 47 µF @ 500 V cjj-47-500
All I know about them is that they should fit in the PCB, don't know if they're any good or not!
If buying from the States they may be good value at the moment with the Pound and Euro so weak.
Motor RUN caps are usually metalized polypropylene. They must pass continuous AC current as long as the motor is running. Wimpy caps explode, so they are usually rather high quality low ESR caps.
Motor START caps are usually non polarized electrolytics since they are only used to start the motor and are then disconnected. Avoid these for any audio application. In fact just avoid them for any application!
C2 is the primary ripple filter in the Simple SE. It can be an electrolytic on the PC borad, an external motor run cap, or both. Using an electrolytic and a motor run cap in parallel will offer improved performance over either one alone. THe total capacitance here should be at least 100 uF. If you have an electrolytic in the board, use whatever you can find cheap on Ebay. 40 uF seems to be common. I have used them. I have also used 100 uF and a 600 uF. If there is no electrolytic in the board and the motor run cap is the only cap use at least 100 uF. The tolerance isn't important as long as you have enough total capacitance.
C1 is the input cap in the Simple SE. It can be an electrolytic on the PC borad, an external motor run cap, or both. There doesn't seem to be much performance advantage from using two types of caps here. The total capacitance value has an effect on the B+ voltage. Values from 25 to 47 uF will give similar voltages. The smaller values are easier on the rectifier tube. Don't go over 47 uF total. Your rectifier might not survive the start up surge.
If I have to use a lone 100uf motor-run cap at C2, where it should be connected? Should I wire/solder it on PCB C2 location? Or should I wire it like supplemental cap as shown in a wiring diagram and leave the PCB C2 location empty.
Can this be used as C2? Its 33uf/500v and all other specs seem to be in order. If not then I must find a 100uf motor run I guess.
http://www.mouser.com/ProductDetail...=sGAEpiMZZMtZ1n0r9vR22dX5NZxAiz78XSJkUEu8NK4=
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I said C2 by mistake..I meant to say C1.
Will this 33uF/500v cap work for C1, since 47uF/500v are out of stock. George mentions using 33/39uF if 47uF can't be found.
380LX330M500H012 Cornell Dubilier Aluminum Electrolytic Capacitors - Snap In
Will this 33uF/500v cap work for C1, since 47uF/500v are out of stock. George mentions using 33/39uF if 47uF can't be found.
380LX330M500H012 Cornell Dubilier Aluminum Electrolytic Capacitors - Snap In
I was just looking through Mouser and they have several 500V CDE caps in stock. They don't have the 47uF, but they do have the 33uF that imnewbie mentioned. They also have the 120uF for the C2 position. I also see a 150uF that's the same height as the 33uF, if that is important. The board will fit up to a 35mm diameter cap. I run a 220uF 35x35mm on mine. There are other options as well and Digikey also appears to stock them. No Panasonic or Nichicon 500V to be found anywhere still.
33uF/500V - 22mm D x 25.4mm L
120uF/500V - 30mm D x 30mm L
150uF/500V - 35mm D x 25.4mm L
33uF/500V - 22mm D x 25.4mm L
120uF/500V - 30mm D x 30mm L
150uF/500V - 35mm D x 25.4mm L
Are there any advantages of using only a motor run capacitor instead of an electrolytic cap at C1? I'm thinking about using one 40uF or 45uF motor run capacitor at C1(wiring it onto PCB C1 location) instead of using the 33uF electrolytic capacitor. 40uF or 45uF motor run are available for $12 shipped on ebay (brands are CSC and Packard).
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