It's a good idea to bleed them individually, just for the sake of redundancy. And the bleeder can double as a voltage equalizer in series stacks.
Rodd, the effect of the bleeder on the amp circuit is just to load the supply a little bit more. Its effect on supply impedance is pretty small (like fifth decimal place), though in the direction of lowering the impedance.
Rodd, the effect of the bleeder on the amp circuit is just to load the supply a little bit more. Its effect on supply impedance is pretty small (like fifth decimal place), though in the direction of lowering the impedance.
SimontY said:
I've never had a problem but in theory, the very large peak currents can do all sorts of toastiness to the insides. Be careful of thin types with high inductance, like vapor-deposited metal film types (although I think these usually have low inductance due to construction) and electrolytics. 'Lytics in particular because of their high energy density, inductance and ESR.
If in doubt about a capacitor, charge it from a good stiff supply to 1.5 to 2 times its rated voltage and repeatedly short its terminals... YEAH, BEHIND A 1" THICK PLATE OF PLEXIGLASS!
(Since most people don't have such plexi, most people shouldn't atempt this. 
)Tim
Go for the gold!
Don't try this at home kids!
My personal record:
I was modding a Dynaco Stereo 70, and kept feeling like It needed more capacitance in the PS. So I kept dasiy chaining caps to it while it was on the bench. I had just finished aobut 4 months of stripping parts from the local universitiy's reuse center (had the personal record for pounds of junk hauled away!), so I had lots of HV screw terminal big can caps.
The bench was shakey.. but the amp was sounding mighty fine.. but then the bench started to collapse....and my beloved '70, (with the original mint Mullards!) was in danger! So I reached out to save it..... and WHAMO!!! 500VDC, with 10,000uf to back it up.. right through the chest... through both arms....
I can't tell you how good that felt. Every nerve trace in my chest and arms hurt for days - it seemed.
All I know, is I gained such a physical memory of the event that my arms hurt and my heart started to speed up and palpatate just about every time I saw any tube gear, for almost a year after that. Especially when I saw exposed HV.....Ouch.
Oh yeah.. i could feel the flavor of the DC, and visited it long enough to feel the tiny amount of AC that was still floating on top. I tend prefer to use scopes to see that, though. The 'lick 'n touch' method is not reccommended.
Don't try this at home kids!
My personal record:
I was modding a Dynaco Stereo 70, and kept feeling like It needed more capacitance in the PS. So I kept dasiy chaining caps to it while it was on the bench. I had just finished aobut 4 months of stripping parts from the local universitiy's reuse center (had the personal record for pounds of junk hauled away!), so I had lots of HV screw terminal big can caps.
The bench was shakey.. but the amp was sounding mighty fine.. but then the bench started to collapse....and my beloved '70, (with the original mint Mullards!) was in danger! So I reached out to save it..... and WHAMO!!! 500VDC, with 10,000uf to back it up.. right through the chest... through both arms....
I can't tell you how good that felt. Every nerve trace in my chest and arms hurt for days - it seemed.
All I know, is I gained such a physical memory of the event that my arms hurt and my heart started to speed up and palpatate just about every time I saw any tube gear, for almost a year after that. Especially when I saw exposed HV.....Ouch.
Oh yeah.. i could feel the flavor of the DC, and visited it long enough to feel the tiny amount of AC that was still floating on top. I tend prefer to use scopes to see that, though. The 'lick 'n touch' method is not reccommended.
Sounds like you had some nasty-assed ground loop. No way in hell should 10,000uF be needed for 200mA!!!
(Oh, and something of condolances to your rather shocking experience)
Tim, showing the pure, raw, inhumane, technical engineer in him
P.S. If you consider that you sunk even as much as 100mA (unlikely(?) since you're still alive), that would be beans for the power supply which could dish out twice as much without excessive sag. I doubt the caps had much effect on increasing the shock...unless the amp then fell to the ground and shorted the rail, releasing the 1.25kJ stored...
(Oh, and something of condolances to your rather shocking experience)
Tim, showing the pure, raw, inhumane, technical engineer in him
P.S. If you consider that you sunk even as much as 100mA (unlikely(?) since you're still alive), that would be beans for the power supply which could dish out twice as much without excessive sag. I doubt the caps had much effect on increasing the shock...unless the amp then fell to the ground and shorted the rail, releasing the 1.25kJ stored...
Re: Go for the gold!
I have no intention calling you names, but I don't belive you touched 10.000uf/500v with both hands and stayed alive to tell that story...
On first place there is no chance that you could let lose those caps.. it neutralizes all of your muscles.. You can't move, and...
You stick to it till you're dead...
And your remark; Don't try this at home kids!.... Maybe you should play with things you understand... Why would you use such capacity on tube amp?????
If you don't understand what you're doing, don't do it or ask somebody who knows.. Electricity is not something you play with..
Yeah right...KBK said:
I have no intention calling you names, but I don't belive you touched 10.000uf/500v with both hands and stayed alive to tell that story... On first place there is no chance that you could let lose those caps.. it neutralizes all of your muscles.. You can't move, and...
You stick to it till you're dead...
And your remark; Don't try this at home kids!.... Maybe you should play with things you understand... Why would you use such capacity on tube amp?????
If you don't understand what you're doing, don't do it or ask somebody who knows.. Electricity is not something you play with.. 
I think clinging to the idea that anything below a certain voltage, x, or frequency, y, is "safe", is itself a hazard. Under the right circumstance something thought to be safe can become dangerous.
For example, something I would have thought to be an urban turned out to be factual last year per a Reuters or AP report from Spain. A toutist there killed himself with an DMM set to read ohms when both probes penetrated the skin. (How and why is too wierd and kinky to report here and maybe the moderators would object.) While outer skin has a resistance measures in M-ohms, and thus protects us somewhat, once past the epidermis resistance drops very low. Humans conduct quite well on the inside. So once the probes penetrated the skin the frequency of the test signal plus the samll voltage and current involved was enough tio cause cadiac arrest.
This should bring to mind the safety rule not work around live equipment if you have cuts or scrapes (even scraped knunkles) on you hands unles you cover them with band-aids (sticking plaster).
For example, something I would have thought to be an urban turned out to be factual last year per a Reuters or AP report from Spain. A toutist there killed himself with an DMM set to read ohms when both probes penetrated the skin. (How and why is too wierd and kinky to report here and maybe the moderators would object.) While outer skin has a resistance measures in M-ohms, and thus protects us somewhat, once past the epidermis resistance drops very low. Humans conduct quite well on the inside. So once the probes penetrated the skin the frequency of the test signal plus the samll voltage and current involved was enough tio cause cadiac arrest.
This should bring to mind the safety rule not work around live equipment if you have cuts or scrapes (even scraped knunkles) on you hands unles you cover them with band-aids (sticking plaster).
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