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  #51  
Old 27th January 2020, 08:45 PM
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Greg. Greg. is offline
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Default Re: Phono II advice Please!

I recall that back in the day when upgrading PSU II, several of us used ceramic caps on the PCB underside to bypass all the large PSU caps.
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  #52  
Old 28th January 2020, 08:42 AM
bob orbell bob orbell is offline
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Default Re: Phono II advice Please!

Thanks' for correction John, I should have read all the chapter on ceramic capacitors. Bob
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  #53  
Old 31st January 2020, 09:32 AM
Lyndon Johnson Lyndon Johnson is offline
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Default Re: Phono II advice Please!

Thanks everyone for your responses. So in summary I have learned that I may hear an improvement if I fit a 10nF capacitor in parallel with each of the four diodes in the HT rectifier bridge, as this will help suppress any switching spikes from the diodes.
Also, 10nF capacitors in parallel with C1,2 and 4 will further reduce the ESR and so help reduce ripple in the DC.
In both cases these can be ceramic.

I will go ahead and let you know how I get on.
Lyndon.
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  #54  
Old 31st January 2020, 01:45 PM
John Caswell John Caswell is offline
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Default Re: Phono II advice Please!

Hi Lyndon,
You wrote "In both cases these can be ceramic."
Ideally they should be ceramic disc types min 1kV rating, which are now becoming difficult to source, as Murata have ceased manufacture.
I bought a batch from eBay suppliers.

John
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  #55  
Old 31st January 2020, 01:53 PM
Lyndon Johnson Lyndon Johnson is offline
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Default Re: Phono II advice Please!

I have ordered Vishay 300V ac ceramics RS part number 183-7414.
There were higher voltage alternatives at higher prices.
Lyndon
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  #56  
Old 31st January 2020, 04:43 PM
John Caswell John Caswell is offline
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Default Re: Phono II advice Please!

Hi Lyndon,
They'll be fine.

John
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  #57  
Old 31st January 2020, 05:34 PM
Chris Chris is online now
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Default Re: Phono II advice Please!

A very interesting post. Something that could have been included in the original design?

I have included some links:

http://www.hagtech.com/pdf/snubber.pdf

https://www.diyaudio.com/forums/powe...-test-jig.html

Chris.
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  #58  
Old 3rd February 2020, 11:24 AM
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Default Re: Phono II advice Please!

Good source for high voltage ceramic caps.

http://www.banzaimusic.com/High-Voltage/
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