PS Audio (Paul McGowan) you tube “Phase Linear Gear”

[Gibsonian]

I'm with Paul. Since doing this on my first 700 which was basically stock but recapped, I've tried to do in on most everything, preamp or power amp. I can typically hear the difference.

 

[mlucitt]

This is actually a very useful thread (and still on topic).
It is important to point out capacitor AC ratings, and never to use a DC only rated capacitor on an AC circuit as Don pointed out.
Capacitors for use in filtering AC are of two different types regardless of uF value.
Type X is a capacitor rating for "across the line" or AC Hot (black) to Neutral (white). This cap should fail open but if it shorts it will open a circuit breaker or blow a fuse. Type X shows up as X1 which is tested to 4,000 Volts, and X2 which is tested to 2,500 Volts.

Type Y is a capacitor rating for "line to ground" or AC Hot to Ground and AC Neutral to Ground. This cap should also fail open but if it shorts and the chassis is not grounded, the case will become "hot". Type Y shows up as Y1 tested to 8,000 Volts, and Y2 tested to 5,000 Volts.

Many AC caps are dual rated such as Mouser P/N 72-VY2103M63Y5US63V0, which is a X1 and Y2 rated capacitor (X1 to 440VAC, Y2 to 300VAC).

 

[marcok]

I'm with Paul. Since doing this on my first 700 which was basically stock but recapped, I've tried to do in on most everything, preamp or power amp. I can typically hear the difference.

But it's necessary for the age and not for noise .
In this case l generally saw loss in path , hum , short and so on .
These are faults . IMHO .
Ciao
Marco

 

[Gibsonian]

But it's necessary for the age and not for noise .
In this case l generally saw loss in path , hum , short and so on .
These are faults . IMHO .
Ciao
Marco

I agree , not for noise, but not for age. Allows the capacitor to behave differently. It simply sounds better.

 

[wattsabundant]

These do, Mouser P/N 598-103MWR630K. At the 630VDC rating, the AC rating is 220VAC; more than adequate for use across the rectifier terminal pairs which should never see more than 200VAC.
Datasheet attached.

Funny you picked this one: A suitable alternative to the film would be Mouser ceramic disc. P/N 72-AY2103M61Y5VS63L0
I have been using this AC-rated ceramic capacitor across the power switch for a long time. P/N 72-VY2103M63Y5US63V0
It is a Y2 300VAC rated capacitor, and the price is $0.48ea. I honestly can't tell what the difference is between the two.

Indeed the cap mentioned above is rated for 220 VAC, although it is peak voltage, not RMS. Of interest is the DVDT spec, but the spec is not defined.

The ceramic disc I mentioned earlier was just one of many that came up in a search at Mouser. I can recall one ceramic disc failure which was used across a power switch on a preamp. I think it had a broken lead. I've seen, I would guess 2 dozen 1000VDC film caps that have ruptured. They typically lasted 5 years or more before failing and did not have an AC rating. These were used "across the line" on a 208 volt, 3 phase source. Finding a suitable cap rated for that application did not reveal a lot of options.

Summary: The film caps may very well be suitable. It may take 5-10 years before we would know for sure. If they do fail, the expected failure mode would be a short circuit and result in a blown line fuse.

Edit: This was posted befored I saw Marks' response above which makes this post somewhat redundant.

 

[mlucitt]

Edit: This was posted befored I saw Marks' response above which makes this post somewhat redundant.

Don, between the two of us we have both seen our share of blown caps. I appreciate your insights. BTW, I just ordered 100 of that ceramic cap you called out. I did the research and found that the cap you mentioned has straight leads (my cap had kinked leads), and your cap is 2mm smaller.
Your cap has a temperature rating of 5VS, mine was 5US. I could not find that spec, but the two ratings are in the same class, so they are similar.
Thanks for your input.

 

[MusicSteve]

These do, Mouser P/N 598-103MWR630K. At the 630VDC rating, the AC rating is 220VAC; more than adequate for use across the rectifier terminal pairs which should never see more than 200VAC.
Datasheet attached.

Funny you picked this one: A suitable alternative to the film would be Mouser ceramic disc. P/N 72-AY2103M61Y5VS63L0
I have been using this AC-rated ceramic capacitor across the power switch for a long time. P/N 72-VY2103M63Y5US63V0
It is a Y2 300VAC rated capacitor, and the price is $0.48ea. I honestly can't tell what the difference is between the two.

I bought and install the P/N 72-AY2103M61Y5VS63L0 for the bridge rectifier 4x. will this also work for the power SW?

 

[mlucitt]

I bought and install the P/N 72-AY2103M61Y5VS63L0 for the bridge rectifier 4x. will this also work for the power SW?

Yes, the cap you specified above is a safety-rated 440VAC cap, perfect for across the contacts of the power switch. Are you using both sets of switch contacts, if two sets are available?

BTW, these caps are not in stock at Mouser until Feb 17, 2023.

 

[MusicSteve]

Yes, the cap you specified above is a safety-rated 440VAC cap, perfect for across the contacts of the power switch. Are you using both sets of switch contacts, if two sets are available?
BTW, these caps are not in stock at Mouser until Feb 17, 2023.

Thanks . I bought a bunch of these because of this this thread , not to long ago, since the other ones were out of stock, so I bought the 2nd kind since they were in stock at that time . I do have the 2-sw Power-sw , So I will use them. I know this Brand is in everything related to input power,,,,