Digital input jack upgrade

[richidoo]

I just swapped the $2 Switchcraft RCA jack I was using for digital input on my Buffalo2 DAC with a WBT Nextgen. The difference is night and day, even playing internet stream. Low mids sound "louder," everything is clearer and more focused. More palpable tone, more intense music.

The switchcraft jack had a circle washer tab for negative contact. It was screwed down with the panel nut. So there was resistance between the nut and the tab, and resistance between the nut and the threads. The barrel on scwitch craft is .0005" too small, so many jacks are too loose, like my Black Cat Veloce digital cable. That's why I switched the jack, to prevent the signal from dropping out when the jack loses contact. But I didn't expect this big improvement in SQ. 

WBT is good stuff! Gold plated copper, with short solid one piece contacts molded into the plastic body, no metal threads.

I was already using WBT Nextgen on the analog outputs.

[DaveC]

I just swapped the $2 Switchcraft RCA jack I was using for digital input on my Buffalo2 DAC with a WBT Nextgen. The difference is night and day, even playing internet stream. Low mids sound "louder," everything is clearer and more focused. More palpable tone, more intense music.

The switchcraft jack had a circle washer tab for negative contact. It was screwed down with the panel nut. So there was resistance between the nut and the tab, and resistance between the nut and the threads. The barrel on scwitch craft is .0005" too small, so many jacks are too loose, like my Black Cat Veloce digital cable. That's why I switched the jack, to prevent the signal from dropping out when the jack loses contact. But I didn't expect this big improvement in SQ. 

WBT is good stuff! Gold plated copper, with short solid one piece contacts molded into the plastic body, no metal threads.

I was already using WBT Nextgen on the analog outputs.

I hate reading these kind of reviews... WBT isn't cheap and I'm a cheapskate! I have a couple pairs of brass RCA female jacks and brass speaker binding posts I'd like to replace with copper, but finding these things at a reasonable price is very difficult.

Have you tried BNC jacks? I believe the male end needs to applied with crimping tools but when I was purchasing a digi coax SPDIF cable DH labs recommended BNC connections over RCAs.

[richidoo]

Hi Dave, I feel as you do, that $45 is too much to pay for a freaking jack, so I have used Switchcraft because it is American and decent quality metal. But I think those temporary contacts screw up the impedance, and of course they are too small.  But I'm sure there are decent RCAs that lie in the middle. Vampire makes some, but I've not tried them. I think ARC uses Vampire, I know Cary did back in the hayday... But the cheapest Vampires are $10-15 each iirc.

I have a few BNC jacks on hand, even a nice one from Neutrik, but I'm too lazy try it! My cable can convert RCA to BNC, so I wlil give it a whirl to quench the curiosity.

[DaveC]

I sprung for Vampire copper RCAs for my amp ($40/pr), but the preamp got brass as I needed 5 pair. I plan to replace the 1st input and main output with copper RCAs sometime in the future. I have used Switchcraft and it's good for what it is... still nowhere near as good as copper. For RCA plugs, I just bought some Furutechs with up-occ copper center pin for about $45 for a set of 4 at partsconnexion, they are having a 20% off sale right now.

I was just looking for copper binding posts and found these Pomona tellerium copper w/ gold plating. I may put them on my amp and hardwire my speakers...

http://www.pomonaelectronics.com/pdf/d3750-3760-3770_101.pdf

It's too bad all the brass stuff sounds so bad and the copper stuff is so expensive... seems like every brass connection you get rid of is a noticeable improvement though.

[richidoo]

Good to know about the pomonas.  Cardas makes some solid copper speaker posts that aren't too outrageous.

The Switchcraft specs say they use copper alloy. But brass is a copper alloy, so....

[rollo]

   The WBT RCA is good. The Audio Note for about $17 [ Parts Connection] is worth a try. I switched from WBT to Audio Note. It is silver over copper. BTW not a silver guy at all but these changed my mind.
  If you use male WBT RCAs try taking off the outer barrel. Or any other RCA for that matter. Made a difference for us. Try and report back. I will offer no comments as to not precondition your experiment.


charles

[Lizard_king]

Rich,

Depending on which SPDIF receiver chip your DAC is using, a BNC is way better than RCA. I have an all out Audio Note Dac Kit Dac and I changed the RCA to a Kings BNC 75 Ohm connector. I then use Ohm ah ha wire from the connector to the board. After some break in time, let me tell you the music shined!

I just swapped the $2 Switchcraft RCA jack I was using for digital input on my Buffalo2 DAC with a WBT Nextgen. The difference is night and day, even playing internet stream. Low mids sound "louder," everything is clearer and more focused. More palpable tone, more intense music.

The switchcraft jack had a circle washer tab for negative contact. It was screwed down with the panel nut. So there was resistance between the nut and the tab, and resistance between the nut and the threads. The barrel on scwitch craft is .0005" too small, so many jacks are too loose, like my Black Cat Veloce digital cable. That's why I switched the jack, to prevent the signal from dropping out when the jack loses contact. But I didn't expect this big improvement in SQ. 

WBT is good stuff! Gold plated copper, with short solid one piece contacts molded into the plastic body, no metal threads.

I was already using WBT Nextgen on the analog outputs.

[richidoo]

Thanks I will definitely try that. I am pretty sure that the receiver is built into the DAC chip.  I have two 2" solid copper leads to the PCB SPDIF input, could be better.  I have some nice 75ohm coax, and maybe I can tie it down closer to the chip.

[bpape]

I would agree that BNC is far superior to RCA of any sort.

Bryan

[Bunky]

I use the BNC on my Minimax DAC with the Black Cat Silverstar75 digital cable .

[DaveC]

I just got a USB DAC and will have no need for my spdif converter and ~10' DH Labs 75 Ohm digi cable w/ a BNC on one end an an RCA on the other...    But now I need a longer USB cable... 

I ordered the Pomona binding posts for my amp and speakers, the price is far less than any other copper binding post I've seen... by a lot.

   The WBT RCA is good. The Audio Note for about $17 [ Parts Connection] is worth a try. I switched from WBT to Audio Note. It is silver over copper. BTW not a silver guy at all but these changed my mind.
  If you use male WBT RCAs try taking off the outer barrel. Or any other RCA for that matter. Made a difference for us. Try and report back. I will offer no comments as to not precondition your experiment.


charles

I looked into those AN RCA jacks, can't find what the base material is made out of anywhere. They are about 1/2 the price of any RCA jack I can find that is all copper, but if you have compared them to WTB and give a thumbs-up I will give them a try.

[DaveC]

Hey Rich, have you tried these? Go down and check out jkeny's response, and he suggests a better part to use... very interesting... Since I have a USB DAC now it's one less thing for me to worry about, but looks like a great idea for spdif. 

http://www.head-fi.org/t/446375/usb-24-192khz-m2tech-hiface/1440#post_6771760

[richidoo]

Not tried that yet, but very interesting!

The attenuator also establishes a precision impedance which is very important to reducing jitter. That's probably the magic with these attenuators used for SPDIF. But with the .5V signal of SPDIF we want as little voltage attenuation as possible.

I couldn't find any 75 attenuators from Miniwatt, but the Pasternack attenuator mentioned is 75ohm.

I wonder if terminating a 75ohm coax cable with 75 resistor right at the receiver chip would do as well at reducing jitter as the attenuator without the deliberate insertion loss? But the attenuator sure is easier to install!

[DaveC]

The Pomona binding posts were one of the best upgrades I've done for the money. Since this isn't a thread about posts, here's a link if you're interested, I posted my impressions in the Omega forum at AC since those are the speakers I'm running.

http://www.audiocircle.com/index.php?topic=108936.0

[rollo]

Not tried that yet, but very interesting!

The attenuator also establishes a precision impedance which is very important to reducing jitter. That's probably the magic with these attenuators used for SPDIF. But with the .5V signal of SPDIF we want as little voltage attenuation as possible.

I couldn't find any 75 attenuators from Miniwatt, but the Pasternack attenuator mentioned is 75ohm.

I wonder if terminating a 75ohm coax cable with 75 resistor right at the receiver chip would do as well at reducing jitter as the attenuator without the deliberate insertion loss? But the attenuator sure is easier to install!

   I believe a pulse transformer at the input of the SPDIF is the way to go. Provides a true 75 Ohm input. Wether BNC or Coaxial the trannie does make a difference for the good.
   

charles