[Danberg]

Have been reading "Audio Circle" with great interest since joining recently. I would like to add Auricaps to my current CD player after reading several posts.  

I have no experience in mods and would like advice on how to properly accomplish my 1st attempt at this.  My question specifically refers to comments made in the post "Upgrading the Cambridge Audio D500 CD Player."  
He states that "putting two 0.47UF 600V Auricaps across the hot/neutral wires in the power input of the player is supposed to filter all sorts of crud out of the power."  
He put them "behind the fuse, so they don't fail and catch fire while the unit is un-attended."

The CD player I want to mod, Rotel RCD-975.

My Questions:
1.  The specs (0.47UF 600V) stay the same regardless of the manufacturer of the CD player?  If not, what specs are recommended?

2. Does he mean connect caps across the AC wires (hot/neutral) that come in through the chassis prior to them connecting to anything on the circuit board?  If not, please describe in more detail.

3.  Cause for alarm?! What?! "Install BEHIND the fuse SO THEY DON'T FAIL AND CATCH FIRE, while the unit is un-attended."   Why would they possibly catch fire?  Is this a mod "for professionals only"?  Or does he mean, insert them somewhere on the wires BETWEEN the fuse and the circuit board?

5. Any recommended sources for Auricaps?

[mgalusha]

Dan,

I'll try to help.

The specs (0.47UF 600V) stay the same regardless of the manufacturer of the CD player? If not, what specs are recommended?

That is plenty and it doesn't really matter what type of CDP it is.

Does he mean connect caps across the AC wires (hot/neutral) that come in through the chassis prior to them connecting to anything on the circuit board? If not, please describe in more detail.

The caps are connected in parallel to each other and to the power input.  One lead of each cap is connected to the hot side (black) and the other to the neutral side  (white). Note the colors listed are semi-standard and may not be the same in your CDP. It really doesn't matter which is hot and neautral for this mod since you are connecting the caps across the leads.

Cause for alarm?! What?! "Install BEHIND the fuse SO THEY DON'T FAIL AND CATCH FIRE, while the unit is un-attended."  Why would they possibly catch fire? Is this a mod "for professionals only"? Or does he mean, insert them somewhere on the wires BETWEEN the fuse and the circuit board?

This is a good idea. The industry makes special AC line rated capacitors that will not short if they fail. Some caps will present a short circuit if they fail. The AC Line rated caps are thus safer. I don't believe the AuriCaps are AC Line rated. This isn't to say that you will have a problem, you probably won't but putting them after the fuse is safer in that if they fail and short the fuse will simply blow.

You can purchase them from quite a few places. Antique Electronics carries them as does The Parts Connexion and Michael Percy.

As with all mods involving AC power, use caution and don't attempt it if you are not certain of your abilities. Not trying to preach just don't want any fried AC members.

mike

[ginger]

He means putting a capacitor across the active and neutral wires of the mains input. For this duty auricap is a massive overkill. Use Auricaps for audio path capacitor upgrades BUT not for filtering High Frequency hash from the mains.

***** VERY IMPORTANT ******
In addition any capacitor which you wire across the mains MUST BY LAW be Class X Safety Rated, either X1 or X2.

Ceramic Disc or metalised polypropylene caps are far more suitable for this application than Auricaps.

In addition if you already happen to be using a powerboard with an inbuilt filter then its a waste of time (and money).

Its unfortunate that amongst the very useful info you find on this site and other similar sites there is some bullshit, occasionaly very dangerous bullshit.

In this case, due to the voltage rating of the Auricap its probably not dangerous, just a waste of money.

If you want to try this mod, buy a X1 Safety Rated ceramic disc or metalised polyproylene cap of the same value. A typical capacitor for this  is less than $1 Australian (about 75 US cents). Pay careful attention to the wiring - you don't want the capacitor leads shorting to anything, particularly not you or anything your likely to come in contact with.

Cheers,
Ginger
(Electonic Design Engineer - Adelaide, AUSTRALIA)

[StevenACNJ]

Chris @ VH audio also carries the Auricaps .47uf 600V (or 1500V). I use the 600V.

I use them through out my system across the AC mains with excellent results.

1. My BPT 3.5 Signature comes from the factory with them installed standard on each recepticle.

2. DVD Player

3. CD Player

4. On each of my 5 monoblock amps.

[MaxCast]

Sounds like you can put these things on anything.  It takes two .47, 600v  wired in parallel across hot and neutral.  Has anyone have experience with Auri's versus the cheeper ones ginger speaks of?

[Andrew JC]

I have been looking into this for a past few days. As far as I can tell Parts Connexion seems to have the best price. However, I don't know what the shipping charges are from Canada.

[Gordy]

Hi All,  I've bought small parts from Parts Connexion on several occasions and don't recall shipping to be anything outlandish ($5-8ish?), as opposed to UPS type shipping to Canada  .

I found out the hard way how easy it was to waste money using the best parts in inappropriate ways (thank you Paul!).  Ginger knows of what he speaks, leave the Auricaps for crossover/signal mods!

Hope this helps...
All the best, Gordy

[randytsuch]

If you go over the audio asylum, at the tweak section, there are quite a few posts on the "auricap mod" or something like that.  Most people have talked about doing it to a CDP.

Seems like more than a few people have done it, and not have a problem.  But, AFAIK, you can only use X or Y caps LEGALLY (per code), for AC mains, like Ginger said.

So, if you do have a problem, and something bad happens, your insurance could refuse the claim for this.

I have x caps in my power conditioner, but was going to get a couple of auricaps, and try them in my CDP.

Randy

[james_b]

The Auricaps do have one lead colored red, and the other is black. They state the red is to be connected to the hot line, and the black to neutral. If your player has an IEC inlet, the easiest way to install them is to solder them on the inside of the chassis on the IEC hot and neutral pins.

[markC]

The Auricaps do have one lead colored red, and the other is black. They state the red is to be connected to the hot line, and the black to neutral. If your player has an IEC inlet, the easiest way to install them is to solder them on the inside of the chassis on the IEC hot and neutral pins.

But this would put the caps ahead of the fuse rather than behind it. So if you had a short the protection you would rely on would be your 15 or 20 amp breaker rather than your 2 or 3 amp fuse in the cdp.

[kana813]

Dear Ginger, Electonic Design Engineer -

Have you tried the Auricaps?

[StevenACNJ]

MarkC

"But this would put the caps ahead of the fuse rather than behind it. So if you had a short the protection you would rely on would be your 15 or 20 amp breaker rather than your 2 or 3 amp fuse in the cdp"

Trust me the fuse will blow before the breaker goes.

[markC]

MarkC

"But this would put the caps ahead of the fuse rather than behind it. So if you had a short the protection you would rely on would be your 15 or 20 amp breaker rather than your 2 or 3 amp fuse in the cdp"

Trust me the fuse will blow before the breaker goes.

Even if the cdp is turned off when the cap shorts?

[kana813]

For those of you considering the use of Auricaps on AC line, I've installed
dozens of them in place of the cheap prerectification filter caps used
in CDP power supplies and other equipment with SMPS units.  These modified power supplies are in use all over the world. There's never been a single case of a Auricap failing.  IMO, for AC noise filtering, Auricaps
are more than worth their asking price.  BALANCED POWER TECHNOLOGIES, and a host of other equipment makers use them in their
produces.

[james_b]

I built a John Risch power filter used on my front projector & satellite HT system, using the recommended parts and it worked well. Later I modified it by placing two .47 uF 600V Solen capacitors inside, on the IEC inlet in the same manner as the Auricap tweak. I thought I would try them since they are cheaper, and they made an even further nice improvement in my video picture. They have been in it for a couple of months now of good use with no problem.