In Reply to: I'm Bored, part ll. MA-1 pictures posted by Cousin Billy on March 9, 2014 at 04:50:53:
Billy.
Without being condescending,you are going about these upgrades all wrong.You have ample room in there do much better capacitance upgrades than you are doing.
First,the 1.5uf clarity across the huge 27000uf capacitors is doing very little other than making the cap see a slightly lower ESR.The problem is,you really need about 1% of the value of the cap you are shunting to be a truly effective shunt and some even say 10%.
Secondly,the computer grade high capacitance electrolytics are extremely slow and have dielectric absorption that is out of sight and out of mind.What that does is,filter out higher frequencies being those caps feed the output tubes and the signal is riding on that rail.
The very least I would do is increase the shunt capacitance across the 27000uf caps to 100uf poly..CDE and Unlytic make them and I use them a lot..They have a 30uf@600v that is the size of a D cell battery and then they make a 100uf@600v that is the size of a small 6 oz Dixie cup.You can even put them in place of the of the 100@350v which would be about 50@700v,being they are in series.You can you a 30uf there and be fine..It's not the amount of capacitance as much as it is the quality of capacitance.I would shunt the 27000ud with a pair of these 100uf polys and I guarantee a huge difference..You can buy them right on ebay cheap because they are govt surplus.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
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Follow Ups
- RE: I'm Bored, part ll. MA-1 pictures - Michael Samra 13:10:20 03/12/14 (27)
- Mike, that output stage supply operates at only 125VDC - Lew 16:49:20 03/12/14 (25)
- RE: Mike, that output stage supply operates at only 125VDC - Cousin Billy 04:18:54 03/13/14 (21)
- 4700uF Panasonic - Lew 11:39:36 03/13/14 (0)
- RE: Mike, that output stage supply operates at only 125VDC - Lew 07:12:31 03/13/14 (19)
- 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)
- RE: Mike, that output stage supply operates at only 125VDC - Michael Samra 17:50:40 03/12/14 (2)
- OTL circlotron - Lew 19:01:19 03/12/14 (1)
- RE: OTL circlotron - Michael Samra 15:49:33 03/19/14 (0)
- And there I have my answer!!!!!!!!!! - Cousin Billy 16:01:46 03/12/14 (0)