Caps are new CDE Illinois 47uF/500V
Amp is original Peavey Classic 30
Supplier is Mouser
Can I assume that these are new enough that they don't need reforming before I install them?
If I DO need to reform them, the best I can do for now is 50VDC and then 100VDC with the equipment I have on hand...
If I install them as is and let the amp idle for a few minutes or hours will they reform (at lease somewhat) while the amp is idling?
I want this amp to be as hum free as possible.
Amp is original Peavey Classic 30
Supplier is Mouser
Can I assume that these are new enough that they don't need reforming before I install them?
If I DO need to reform them, the best I can do for now is 50VDC and then 100VDC with the equipment I have on hand...
If I install them as is and let the amp idle for a few minutes or hours will they reform (at lease somewhat) while the amp is idling?
I want this amp to be as hum free as possible.
I don't know about your PSU caps, but caps in photo flash don't take ling to reform. Just a few flash charge/discharge cycles and they are ready to go again. I can't think yours would need more than that, if anything. Just install them and use them - they will take care of themselves.
Would say that new (less than a couple of years old) would have been formed when they were made and should be perfectly fine to use.
Even "new" electrolytic capacitors can actually be years old, having sat on the shelf in the warehouse(s).
There will be a 4 digit date code on them, consisting of the last two digits of the year of manufacture, (00 to 99),
and the month (01 to 12). At least some reforming through a series 10k power resistor is best (in the right polarity).
Never connect capacitors to be reformed directly to a voltage supply, the current must be limited (with 10k resistor).
There will be a 4 digit date code on them, consisting of the last two digits of the year of manufacture, (00 to 99),
and the month (01 to 12). At least some reforming through a series 10k power resistor is best (in the right polarity).
Never connect capacitors to be reformed directly to a voltage supply, the current must be limited (with 10k resistor).
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It's odd that my caps DO have a date code, but it is just "29". Can't believe it means 2012_09. I called Illinois Caps to get it deciphered; everyone out for vacation until tomorrow. Meanwhile the protocol for reforming is minutes to an hour soak at progressively larger voltages like 100, 200, to the rated limit, through a 10K to 33K current limiting resistor of 5 or 6 watts.
What I have is a vintage HP (later Keysight) 6228B dual DC power supply. No high wattage resistors bigger than 50 ohms and no Radfio Shack in the mall any mire. I can dial in current limiting in the HP which should work. I can daisy chain the 2 50V sides to get 100V max and limit the current to 500mA (I think, never tried it before) so I could give them an hour at 100V even if the date code turns out to be fresh (<6 months).
So All Is Well. Thanks.
What I have is a vintage HP (later Keysight) 6228B dual DC power supply. No high wattage resistors bigger than 50 ohms and no Radfio Shack in the mall any mire. I can dial in current limiting in the HP which should work. I can daisy chain the 2 50V sides to get 100V max and limit the current to 500mA (I think, never tried it before) so I could give them an hour at 100V even if the date code turns out to be fresh (<6 months).
So All Is Well. Thanks.
Current should be limited to 10mA or less, if possible. Use several low wattage resistors in series
if necessary, to get around 10k.
if necessary, to get around 10k.
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Will do (limit current to 10mA).
Found out that the date code of "29" means 2nd half of 2019, i.e. a bit more than a year old. So I'll do what I can to break them in. I have an HP 6228B dual dc power supply. With the dual outputs in series I can get to 100Vdc and can control the current. I'll test how low it can go before I install the caps. Wish I could go higher, but I give them a good few hours at 50V, then 100V, and then put 'em in...
Found out that the date code of "29" means 2nd half of 2019, i.e. a bit more than a year old. So I'll do what I can to break them in. I have an HP 6228B dual dc power supply. With the dual outputs in series I can get to 100Vdc and can control the current. I'll test how low it can go before I install the caps. Wish I could go higher, but I give them a good few hours at 50V, then 100V, and then put 'em in...