[davide256]

The annoying thing about the Eitr is that its power supply is stepped down AC wall wart. I've gotten big gains from other components in the digital signal path by replacing/upgrading their DC power supplies but so far the Eitr
stymies me on how to make a like PS improvement...

 

[PunchLine]

The annoying thing about the Eitr is that its power supply is stepped down AC wall wart. I've gotten big gains from other components in the digital signal path by replacing/upgrading their DC power supplies but so far the Eitr
stymies me on how to make a like PS improvement...

You are aware Schiit explicitly and unequivocally states there's no room whatsoever for a power supply upgrade?

It's in the product Q/A area.

 

[PunchLine]

My main gripe with with the Eitr is the single directional USB port. I would have loved it to charge my DAP.

A bnc instead of RCA would've a welcome change too.

 

[Ableza]

My main gripe with with the Eitr is the single directional USB port. I would have loved it to charge my DAP.

A bnc instead of RCA would've a welcome change too.

 

[Ableza]

The annoying thing about the Eitr is that its power supply is stepped down AC wall wart. I've gotten big gains from other components in the digital signal path by replacing/upgrading their DC power supplies but so far the Eitr
stymies me on how to make a like PS improvement...

The P/S is a linear low-noise unit, but you could replace it with another if you choose. It's 6VAC 1.5A.

 

[PunchLine]

Thanks for the tip, my good man, but it's not an issue of physical interface.

As far as I know, RCA interface doesn't have exact and specified impedance, whereas BNC is either 50 or 75ohm. Thus, theoretically, given a matching impedance cable, BNC performs better than RCA.

 

[theveterans]

Thanks for the tip, my good man, but it's not an issue of physical interface.

As far as I know, RCA interface doesn't have exact and specified impedance, whereas BNC is either 50 or 75ohm. Thus, theoretically, given a matching impedance cable, BNC performs better than RCA.

Most of the RCA cables I see advertised as digital COAX is specked to 75 ohms and the XLR digital is specked at 110 ohms IIRC

 

[PunchLine]

Most of the RCA cables I see advertised as digital COAX is specked to 75 ohms and the XLR digital is specked at 110 ohms IIRC

I think "advertised" is the operative word.

Blue jeans cables suggests true 75ohm isn't attainable with rca plugs.
http://www.bluejeanscable.com/articles/75ohmrca.htm

Not trying to push any bottons, merely for educational purpose.

 

[Ableza]

Thanks for the tip, my good man, but it's not an issue of physical interface.

As far as I know, RCA interface doesn't have exact and specified impedance, whereas BNC is either 50 or 75ohm. Thus, theoretically, given a matching impedance cable, BNC performs better than RCA.

S/PDIF is a 75 ohm spec. RCA or BNC. It’s the same.

 

[PunchLine]

S/PDIF is a 75 ohm spec. RCA or BNC. It’s the same.

No, RCA plugs aren't true 75ohm. Peruse the link to blue jeans cables above.

There's a reason you'll find almost exclusively bnc on pro equipment. Professionals shun RCA.

 

[Ableza]

No, RCA plugs aren't true 75ohm. Peruse the link to blue jeans cables above.

There's a reason you'll find almost exclusively bnc on pro equipment. Professionals shun RCA.

Except that it doesn't matter unless your cable run is over 10 meters. RCA will sustain a 75-ohm cable impedance to that length. Or at least it does according to ANSI.

 

[whodiini]

Lots of confusion here. There are 2 parts of a cable: the cable and the connector. The cable is typically coaxial and can be the same whether it uses a RCA and BNC connector. A coax cable is uniform impedance whether it is 1 inch or 100 ft. Now the connector: a BNC can be the same impedance as the cable. If it is the same impendance, a signal will propagate without relfections. It is is mismatched, then the signal will be distorted by reflections. The problem with RCA is that it is a cheap connector designed to be the lowest cost you can get away with. It was never intended to be used for impedance matched circuits. The impedance is governed in a connector by 2 things - the material or dielectric insulator and the diameter of the connector. Since RCA has a set diameter, then the only way you can get the right impedance is to find a material that makes it the right impedance. I know of only 1 manufacturer that claims a impedance matched RCA connector. The rest of the RCAs are not the same impedance. Now the question is whether the impedance mismatch is of any practical difference in an RCA. For audio signals, no because the frequency is low, For digital, where the frequency, esp with DSD is high, yes. I prefer to simply use balanced cables instead of RCA where there is a choice instead of using an adapter.

 

[zalive]

Regarding reflections, I'm not sure whether they do any harm at all if coax is sufficiently long. Reflection travels back to the source then forth to the receiver. In case transition is already sampled reflection should not harm it.
However the quality of connector is not just about impedance, as jitter is not the only aspect of the transmission.

For the example I've made a coax using cheap Rean (Neutrik) RCA connectors, and in comparison to better RCA connectors the detail and airiness is not on the same level. While the impedance on both is wrong on both and cable length was sufficient to avoid S/PDIF transfer jitter. So I guess the answer for the difference is on the noise side, not on the jitter side. Lousy conducting material (funky alloys), Eddy currents in a meaty metal body...

Recently I've started using Taiwanese RCA connectors from the ebay, which are good for analog connections too. It's one point contact system with minimum metal (tellurium copper) used (hollow centre pin, one point outer contact, plastic socket instead of metal one), similar to Eichmann Bullet RCA's (but much cheaper lol). Person which recommended them replaced his WBT's on his analog interconnect with those, and was amazed of the improvement. He uses similar for digital interconnects too. Because a quality connector is a quality connector wherever you use it - noise is a noise.

 

[davide256]

Regarding reflections, I'm not sure whether they do any harm at all if coax is sufficiently long. Reflection travels back to the source then forth to the receiver. In case transition is already sampled reflection should not harm it.
However the quality of connector is not just about impedance, as jitter is not the only aspect of the transmission.

For the example I've made a coax using cheap Rean (Neutrik) RCA connectors, and in comparison to better RCA connectors the detail and airiness is not on the same level. While the impedance on both is wrong on both and cable length was sufficient to avoid S/PDIF transfer jitter. So I guess the answer for the difference is on the noise side, not on the jitter side. Lousy conducting material (funky alloys), Eddy currents in a meaty metal body...

Recently I've started using Taiwanese RCA connectors from the ebay, which are good for analog connections too. It's one point contact system with minimum metal (tellurium copper) used (hollow centre pin, one point outer contact, plastic socket instead of metal one), similar to Eichmann Bullet RCA's (but much cheaper lol). Person which recommended them replaced his WBT's on his analog interconnect with those, and was amazed of the improvement. He uses similar for digital interconnects too. Because a quality connector is a quality connector wherever you use it - noise is a noise.

Suffering attention deficit? This thread is about Eitr, and USB/SPDIF converters... lets not go off topic with personal "religious arguments" about cable design principles.

 

[davide256]

My main gripe with with the Eitr is the single directional USB port. I would have loved it to charge my DAP.

A bnc instead of RCA would've a welcome change too.

mm, perhaps + BNC ... I really wouldn't have bought the Eitr if it meant buying a different high cost coax cable.