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Haninger

Power Options for Switches

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I use a Cisco SG-200-08 switch for my audio system, television, and AppleTV. The switch is connected (via Cat6 in the wall) to a Verizon router which is in a closet on a different electrical circuit.

 

Currently, I'm using PoE from that closet to power my Cisco switch, but I've been told to avoid PoE because it can negatively effect SQ. Not sure if that is true, but would appreciate thoughts.

 

As the Cisco switch is on the same electrical circuit as my audio system, I could power with a LPS and I might have an extra output already. Does anyone know the input DC voltage and amps required for the Cisco SG-200-08? For some reason, I can't find this information online.

 

Thanks!

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Or, just take a look at the original wall wart - it should be labeled with the V and A rating.

 

 

Sent from my iPad using Computer Audiophile


 

Analog:  VPI Scoutmaster / Shelter 501MkII, Sony XRD1 HD FM, Nakamichi BX-300  Music Server:  i7-6700K/Asus RTX2080 OC Gaming, HQPlayer

DACs:  dCS Debussy, Lampizator Golden Atlantic, McIntosh D150 / MCT450 CD/SACD

Digital Add-ons:  Uptone JS-2s and LPS-1s, ISO REGENS     NAA:  NUCs (2), SoTM SMS-200 Ultra / tX-USB Ultra / Network Switch Clock Mod

Preamp:  McIntosh C500P (SS)   Amp:  McIntosh MC452

Speakers:  Wilson Yvette    Signal Cables:  Transparent Ultra Gen V    Power Cables:  Shunyata and PS Audio

GIK Room Treatments   PS Audio P10 AC Regenerators (2)  Dedicated 20 AMP AC circuit

 

 

 

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One thing to consider is that the higher end Cisco switches don't appear to use an SMPS power supply. They use a standard 3-Prong AC cable stright to the wall verses an external brick. I can't say for sure if the internal power supply is an SMPS or not but based on my own caveman testing with an AM radio it's far less noisy then the other switches I've tested from the likes of Belkin, Linksys and ASUS ...etc which all use an external SMPS brick.

 

I use a Cisco Catalyst 2960G which uses the standard 3prong cable as described. Whether or not any of this matters in terms of SQ is another story but I sleep better thinking it might only because all my computer audio related gear shares its ports so maybe there is less chance of all those physical connections polluting each other from an electrical standpoint. In terms of delivery of the 1/0's I have no belief it matters at all.

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One thing to consider is that the higher end Cisco switches don't appear to use an SMPS power supply. They use a standard 3-Prong AC cable stright to the wall verses an external brick. I can't say for sure if the internal power supply is an SMPS or not but based on my own caveman testing with an AM radio it's far less noisy then the other switches I've tested from the likes of Belkin, Linksys and ASUS ...etc which all use an external SMPS brick.

 

I use a Cisco Catalyst 2960G which uses the standard 3prong cable as described. Whether or not any of this matters in terms of SQ is another story but I sleep better thinking it might only because all my computer audio related gear shares its ports so maybe there is less chance of all those physical connections polluting each other from an electrical standpoint. In terms of delivery of the 1/0's I have no belief it matters at all.

 

I can guarantee that even the higher end Cisco routers--with built in power supplies--are using an SMPS. Notice how their IEC inputs don't have a switch to go from 120>240V operation? They are labeled 100V-240V input. Only SMPS units do that. A linear would have a dual primary and a switch to series or parallel them.

 

 

Sent from my iPad using Computer Audiophile

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I can guarantee that even the higher end Cisco routers--with built in power supplies--are using an SMPS. Notice how their IEC inputs don't have a switch to go from 120>240V operation? They are labeled 100V-240V input. Only SMPS units do that. A linear would have a dual primary and a switch to series or parallel them.

 

 

Sent from my iPad using Computer Audiophile

 

You may very well be right..

 

But I do know that whatever PS they are using inside the Catalyst Cisco switch is significantly "quieter" then the other flavors I mentioned previously.

 

I should note that I'm not against SMPS's by any means (heck, every audio component I own uses one) but those cheap little "bricks" given away for a few pennies with most gear are almost always VERY nasty in terms of their radiated pollution and backwash.

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On 12/1/2017 at 2:33 AM, Superdad said:

 

I can guarantee that even the higher end Cisco routers--with built in power supplies--are using an SMPS. Notice how their IEC inputs don't have a switch to go from 120>240V operation? They are labeled 100V-240V input. Only SMPS units do that. A linear would have a dual primary and a switch to series or parallel them.

 

 

Sent from my iPad using Computer Audiophile

 

Hi Superdad,

 

Can i power the Cisco SG-200-08 and the AQVOX switch with the LPS-1?

 

Regards

 

 


Fully Grounded Audio Room - Topaz 1KVA - DIY Power Bar with OYAIDE outlets - MacMini (late 2012) Server  - LUSH USB Cable - DENAFRIPS Terminator DAC - Tellurium Ultra Black XLR - KINKI EX-M1 - PMC Twenty5 26. (power cords LessLoss DFPC Signature)

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Thought I should chime in. I have the Cisco 2960 as well. 

 

I removed the internal SMPS (12V) and installed a 2.1mm DC input. I am currently, using a JS-2 to power the switch. Having tried two other much cheaper LPSs, I can say the LPS quality does make a difference. 

 

Compared to a Netgear Nighthawk switch, powered using the same setup, the Cisco clearly sounds better.

 

Also, I don’t recall the difference between internal SMPS vs. external LPS. I did this a long long time ago. 

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I use a JS-2 to power my Cisco switch also. I don’t know if the sound improvement is due to supplying the switch with cleaner power, that reduces noise on the output, or if the JS-2 puts less noise back onto the AC line than the SMPS. Either way, it’s just better!  I’ll buy the EtherRegen when it’s available and hope for more improvement. 


SonicTransporter > UltraRendu > Ayre QX-5 Twenty > Ayre KX-R Twenty > Ayre MX-R Twenty > YG Kipod II Signature Passive

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My recollection, from the one time I opened my Cisco 2960, is that the 12V SMPS supply in it is rated at just 0.6A—well within the capabilities of an UltraCap LPS-1.2.

I have not bothered to mod mine for an external supply because, well obviously we have our own switch coming soon. 9_9

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On 1/8/2017 at 4:25 PM, Haninger said:

Currently, I'm using PoE from that closet to power my Cisco switch, but I've been told to avoid PoE because it can negatively effect SQ. Not sure if that is true, but would appreciate thoughts.

 

Don't worry, PoE to power the switch works just fine as long as you don't use wrong type (shielded) of cables to connect your audio devices. Network signals between switch and devices are transformer isolated. Shielded cables would connect grounds together and create possibility for all kinds of dirty leakage currents. One of the points of using ethernet for audio is that it allows isolation for example USB doesn't. So only use standard UTP cables!

 

I also power some of my switches and all wireless access points over PoE.

 

 

All built in PSUs of switches are SMPS for efficiency, size and heat reasons.

 


Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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