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Vintage threads from the first ten years

mustard values

10/19/2005 9:34 PM
anonymous	mustard values Hello. I would like to know the 'correct' voltage ratings of the caps used in vintage marshalls. I know there were a few .022/400, but what about the .68 and .1? Which were the voltage ratings for these?

10/19/2005 10:34 PM
Dai Hirokawa	(As found in old Mashalls) it was 160V for the .68uF and 400V for the .1. The .68uF's voltage rating doesn't need to be that high for the cathode bypass though (it could be 6V). I forget but the voltage ratings may not have been made really low for the Philips mustards probably due to vacuum tube circuits (which typically run higher than solid state) being more common at the time they were in production. Also the .1uF in the PI grounding a grid doesn't need to be 400V. It can be lower. In JCMs you'll find 250V for that one and the .1uF presence.

10/19/2005 10:34 PM

Dai Hirokawa
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(As found in old Mashalls) it was 160V for the .68uF and 400V for the .1. The .68uF's voltage rating doesn't need to be that high for the cathode bypass though (it could be 6V). I forget but the voltage ratings may not have been made really low for the Philips mustards probably due to vacuum tube circuits (which typically run higher than solid state) being more common at the time they were in production. Also the .1uF in the PI grounding a grid doesn't need to be 400V. It can be lower. In JCMs you'll find 250V for that one and the .1uF presence.

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10/20/2005 11:26 AM
anonymous	Dai, Thank you very much. I didn't know the correct values used in these amps, but now, thanks to you, I know for sure. There's a lot of argumentation about who really made these caps, BTW. And that was just 40 years ago!

10/20/2005 9:17 PM
Dai Hirokawa	hi, check this page out for some good info on the Philips mustards (don't forget to look at the datasheet too!) : http://amp-restoration.com/parts_info/mustard.html

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