Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Medman on November 01, 2013, 12:17:19 pm
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Is the can on top of caps for safety or something else. I am doing a revibe and I am thinking about mounting filter caps on top on board. Thanks JP
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That 'sardine' can protects you from touching the caps and getting a nasty jolt! The caps on my revibe are on top of the chassis but I used different style caps...
(http://home.comcast.net/~seluckey/amps/revibe/revibe_11.jpg)
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I like your chassis sluckey I have looked at those walnut sided chassis and wondered if I could make them work you even got a reverb tank on yours.
Bill
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Im slow I missed it was a revibe . looks cool
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Originally manufacturers used cap cans to save money..because it was quicker and easier and cheaper for them to just connect one can to the amp and solder 3 wires than it was to connect 3 or 4 caps into a board and solder 6 or 8 wires. Nowadays we know that unless you use each of the sections in parallel with just one ground, or unless you have a custom can with separate grounds, then using cap cans is not the best way to go. They are also more expensive than discrete caps and are not available in as many values.
Greg
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Nowadays we know that unless you use each of the sections in parallel with just one ground, or unless you have a custom can with separate grounds, then using cap cans is not the best way to go.
If you plan wisely there is no issue using cap cans still to this day. Using them grouping the power amp nodes' grounds from the preamp nodes together is fine. If using the familiar (Marshall & Doug's) buss bar approach there is nothing gained using separate caps as it negates the effort in doing so. So caps cans are fine there too. Cap cans can be better than discrete caps having lower ESR, impedance, & higher voltage ratings w/ less space used inside your chassis. Either way, using them in the power amp section is a good choice. Don't believe everything you see and read. Many people have many other issues in building their stuff that's easy to point a finger at cap cans unnecessarily. A primary example is tranny placements; proximity & orientation - this can easily blow the cap can issue along with grounding technique right out of the water.
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If you plan wisely there is no issue using cap cans still to this day. Using them grouping the power amp nodes' grounds from the preamp nodes together is fine. If using the familiar (Marshall & Doug's) buss bar approach there is nothing gained using separate caps as it negates the effort in doing so. So caps cans are fine there too. Cap cans can be better than discrete caps having lower ESR, impedance, & higher voltage ratings w/ less space used inside your chassis.
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I look to them first mainly because I have never gotten a bad one. Cans also add space a in the chassis and usually make for a cleaner build. I also think i have a preference to them as they were used in radio often and the first amp I ever built was a Marshall Plexi Clone. Plus they simply look cool to me. Look at Sluckey's revibe. Very pretty build and those 2 black caps just seem to fit the design. I wish the higher voltage ones from the past were still readily available. Like on a Princeton Reverb 1164, I have seen the caps zip tied to the edge of the board, but it is still a lot of parts inside a small chassis. It is true you must replace 2 or more caps at time which could be more money, but I know a very few people who will not replace all the filter caps when replacing one, but I have seen it done.