In Reply to: RE: Mike, that output stage supply operates at only 125VDC posted by Lew on March 13, 2014 at 07:12:31:
With no load it can exceed 150 volts so a 200V device is prudent.
I don't agree with Dave's assessment that the quality of the cap is more valuable than the value of the part. There are timing constants involved, and since the amp is full power to 2 Hz you can get into trouble if the timing constants in the power supply are not as low as that of the amp itself.
In the stock driver supplies the timing constants are to -3 db at about 0.8 Hz. If you cut the value in half you will introduce IM distortion no matter what kind of cap you have. IOW the 200uf amounts seen in the supply are adequate, don't allow for less than that value or you open a can of worms. As we all know, once such a can is open, it take a whole lot bigger can to get them all back inside again :)
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Follow Ups
- Correction- the supply voltage is a little higher. - Ralph 11:48:52 03/13/14 (18)
- SUCCESS. Thank you everyone - Cousin Billy 16:08:57 03/16/14 (5)
- SUCCESS. Then a step backwards - Cousin Billy 17:56:45 03/17/14 (4)
- RE: SUCCESS. Then a step backwards - Lew 10:21:43 03/18/14 (3)
- just a FWIW - Ralph 12:14:45 03/18/14 (2)
- I guess you are suggesting - Lew 13:13:07 03/18/14 (1)
- not exactly - Ralph 13:27:31 03/18/14 (0)
- RE: Correction- the supply voltage is a little higher. - tyu 12:01:57 03/13/14 (11)
- Some of the older amps had lower voltages - Ralph 14:15:41 03/13/14 (10)
- My education continues - Cousin Billy 17:23:42 03/13/14 (3)
- an I raise the 200uF values simply by installing a film cap across each 100uF pair? - Lew 19:06:37 03/13/14 (2)
- RE: an I raise the 200uF values simply by installing a film cap across each 100uF pair? - Cousin Billy 04:15:06 03/14/14 (1)
- RE: an I raise the 200uF values simply by installing a film cap across each 100uF pair? - Lew 11:00:58 03/14/14 (0)
- I guess I measure about 132V, most days,... - Lew 16:32:52 03/13/14 (4)
- In the case of Billy's amps - Ralph 08:30:19 03/14/14 (3)
- Last Question? - Cousin Billy 10:02:10 03/20/14 (2)
- the downside - Ralph 10:44:01 03/20/14 (1)
- RE: the downside - Cousin Billy 13:08:36 03/20/14 (0)
- RE: Some of the older amps had lower voltages - tyu 15:58:52 03/13/14 (0)