Cisco 2940 switch set up - help needed

[Lindsayt]

there also the argument that using a switch with an external wall wart would be better as you can add a linear PSU to reduce PSU noise

You can also bypass the internal power supply in a Cisco or HP Procurve business switch.

Some models, eg C2924M even have sockets for DC input on the back of them.

[Bencat57]

@montechristo358 thanks for your suggestion but two things come to mind . First is adding a decent LPSU will greatly increase the cost but as you say may well work well .

The other is that these are switches designed to be used in a small business and often in large mutiples around a network . Cisco design and make the internal power supply to a high standard and with very low noise in mind as adding lots of noise to the system could make it not work . These were never meant to be cheap switches it is just that there are so many about as they an old design. I doubt that a home switch with LPSU would improve on the low noise these come with as standard .

[Lindsayt]

Here's some photos of the power supply from an old Cisco 2924M XL switch:

https://cromwell-intl.com/networking/ci ... ch-repair/

I don't know if this is a quality power supply or not.

[karatestu]

It's a switch mode. Nuff said, although if it's good enough for Linn

[CN211276]

It is my understanding that the Cisco swiches have good power supplies, I would not consider adding one.

[montechristo358]

@montechristo358 thanks for your suggestion but two things come to mind . First is adding a decent LPSU will greatly increase the cost but as you say may well work well .

The other is that these are switches designed to be used in a small business and often in large mutiples around a network . Cisco design and make the internal power supply to a high standard and with very low noise in mind as adding lots of noise to the system could make it not work . These were never meant to be cheap switches it is just that there are so many about as they an old design. I doubt that a home switch with LPSU would improve on the low noise these come with as standard .

assumption? or do they publish specs? have your measured (appreciate that's a dirty word, but for a PSU noise I think its fair)

[montechristo358]

it also doesn't have to be expensive. the 12V version of Docs recommended Chinese LPSU is less than £50 last time I looked

[Bencat57]

Used testing the best I have my ears which tell me that when connected background mush and noise is very much reduced and the music sounds better . Do I need to prove this ? Not really my equipment my music , my ears . Could it be just my brain fooling me , yep that is very likely but as it is me listening not that bothered . The above may all be true and you may well be right that an off board LPSU would improve matters but in my case as the unit does not have any input for the supply then no real point wondering . It will still put the cost up by 200% plus (now units will attract VAT on entry so at least 20% on the £50 cost ) as this brand new in the box switch cost £25 delivered and works feels very well made and according to my brother will work longer than I will live now with what it does . If I was foolish enough to fall for the audiophile switches at £1000 plus then being ocd about a power supply makes sense in the context of what I spent and what improvement I got will just relax and listen to the music unless some kind person comes along and lets me have a load of items to test for nothing .

Please do not read this as me being defensive or not doubting what you are saying I have heard what better LPSU units can do and have three of them already to power my media server , MiniDSP units and Media Player all of them worth doing . Powering my router and for me no difference but as I have the unit to try worth listening to . It is just with the switch there is no chance to use one it currently sounds very good so I need to just leave it alone .

[montechristo358]

interesting so you reckon you can hear a difference with the Cisco switch installed?

wasn't questioning your assessment so much as the statement you made that Cisco make to a very high quality standard

The first is fair comment the latter just an assumption unless tested

[Bencat57]

if you read back on the thread i do say that yes the audio quality was improved . I also found that the picture quality on my 4K TV for both 4k and HD playback was more detailed and clearer . This may say lots of things about the quality of my network but this switch has most certainly improved things in a good way.