Capping unused outputs

[Gaius Julius]

Hi all,

I ordered some rca an xlr plugs yesterday to cover unused outputs in my system. I have a pair of unused, non-switchable XLR outputs on my DAC (Antelope Audio Zodiac) and two pair of unused, non-switchable RCA outputs on my preamp (The Gryphon BelCanto) one pair analog out and one pair d-out.

My reasoning is as follows: if these outputs are in parralel to the used outputs, any static that is picked up is going through the signal. (Don't know if this is correct, can anyone confirm this?) So capping unused outputs should hopefully improve signal to noise ratio.

I plan to test it by:

1 listening to the amount of static on high volume without signal before and after

2 "measuring" to the amount of static on high volume without signal before and after with a phone-app

3 normal listening test with music before and after

The caps should arrive later this week, possibly early next week. In the meantime any input/correction on my theory and proposed tests is appreciated.

 

[tinkywinkydipsylalapo]

I ordered some rca an xlr plugs yesterday to cover unused outputs in my system. I have a pair of unused, non-switchable XLR outputs on my DAC (Antelope Audio Zodiac) and two pair of unused, non-switchable RCA outputs on my preamp (The Gryphon BelCanto) one pair analog out and one pair d-out.

My reasoning is as follows: if these outputs are in parralel to the used outputs, any static that is picked up is going through the signal. (Don't know if this is correct, can anyone confirm this?) So capping unused outputs should hopefully improve signal to noise ratio.

Not too sure simply covering the sockets with caps, or just inserting plugs into them, will help, but some seem to swear by the use of 'shorting plugs', which have a resistor connected between their + and - connectors, on unused analogue inputs, as a means of stopping RF interference getting in through those inputs.

Not tried it myself, as life's too short (if you'll pardon the pun), but the idea's been around for ages and, as I say, some seem to think it makes a big difference. However even the advocates suggest the efficacy may vary from product to product, depending on the way the input stages are designed.

Google 'RCA shorting plugs' and you'll find endless suggestions and discussions!

 

[Gaius Julius]

I think most modern preamps have a design that shorts the inputs when they aren't used. I can try to see if capping inputs makes a difference other than keeping dust out.

The outputs can only be covered as shorting them would damage components.

 

[Gaius Julius]

So, the caps arrived today.

Installed them: 2XLR caps on the antelope audio zodiac dac outputs, 4 RCA caps on the Gryphon BelCanto preamp outputs and 6 on the remaining inputs. On a very high volume (11 out of 20 on the stepped relays) without signal the difference seemed to be 3db at 15 cm from the speaker according to my iphone app. However this is volume level is never used, with signal it would propably send the speakercones flying through the room.

While listening at normal volume I couldn't really hear any differences, so that's a bit disappointing.

Oh well, the caps do look very fancy. I now get what people mean when they talk about hifi jewelery *smile* And they'll keep the contacts clean, so that's good

Equipment used:

Caps: Sieveking RCA and XLR caps, DAC: Antelope Audio Zodiac Silver, Preamp: The Gryphon BelCanto, Amp: The Gryphon S100, Speakers: Usher Be 718DMD