Brief Odac impressions - Page 99

It's happened (just once) to me also (sudden muting of ODAC, requiring replug). But I don't think it's ever happened with my onboard audio. I don't have another USB DAC.

Always fun to join a battle. :-D .

I have a 60cm cheapo ebay USB cable without a ferrite bead collar, and I have my quite solid clip+ 12cm cable with ferrite bead.

Listening (non DBT) with etymotics, O2/ODAC to folk and electro and I can't hear a difference.

Disclaimer, my expectation bias was : to not hear a difference.

The result of this worthless attempt is that I haven't tested the question in an objective manner, I've meaninglessly added a worthless opinion and I am happy to use ferrite-beadless cables with a much more convenient length to them and will not bother buying a more expensive one.

Ha ha!!!
Edited by lorriman - 2/10/13 at 8:08am

I was having the same problem until I put my PC on a UPS with voltage regulation. Haven't had a drop out since.

Which reminds me, when I turn my electric heater on or off I get a sharp transient.

A usb cable has a  +VDC and a GND or -VDC.

A usb cable has a +Data and a -Data. 

 

The voltage is DC, not analog.

The Data is DC not analog.

 

Any AC being introduced in the lines from the PC should be handled by the Choke in the ODAC.

Any induced RFI or EMI should be handled by the shield of the cable and the ferrite bead.

 

 

 

Alex

AFAIK a choke is effectively the same as a ferrite bead. And it's doing the same job as a ferrite bead. One of the reasons why my expectation bias was against hearing any difference because the ODAC designer already had this covered.

And I don't think chokes have anything to do with AC, but I could be wrong. That would be diodes and capacitors.

rather than re-writing this in my own words: Chokes definitelty have something to do with AC.

 

A ferrite bead is a passive electric component used to suppress high frequency noise in electronic circuits. It is a specific type of electronic choke. Ferrite beads employ the dissipation of high frequency currents in a ferrite ceramic to build high frequency noise suppression devices. Ferrite beads may also be called blocks, cores, rings, EMI filters, or chokes.^[1]

 

The name comes from blocking—“choking”—high frequencies while passing low frequencies. It is a functional name; the same inductor is often called a “choke” if used to block higher frequencies, but a “coil” or “inductor” if, say, part of a tuned circuit.

 

Ferrite beads are one of the simplest and least expensive types of interference filters to install on preexisting electronic cabling. For a simple ferrite ring, the wire is simply wrapped around the core through the center typically 5 or 7 times. Clamp-on cores are also available, which can be attached without wrapping the wire at all. Although the wire is not coiled around the core for this type of ferrite bead, the introduction of the ferrite core around the wire increases the self-inductance of the wire and thus still has the effect of absorbing energy from the noise traveling in the wire. If the fit is not snug enough, the core can be secured with cable ties, or if the center is large enough, have the cabling looped through one or more times. Small ferrite beads may be slipped over component leads to suppress parasitic oscillation.^[2]

 

^{A choke is a coil of insulated wire, often wound on a magnetic core, used as a passive inductor which blocks higher-frequency alternating current (ac) in an electrical circuit while passing signals of much lower frequency and direct current by having an impedance largely determined by reactance, which is proportional to frequency. Chokes are typically used as the inductive components in electronic filters.}

 

^Alex

let me add that many poeple really do not understand AC, AF, RF, DC what these things really are and how to they relate if at all.

 

i could sit here and BS you with things like: hey what frequency is the DC for the USB buss that supplies the USB Power to the ODAC?

 

the idea for a usb cable that shielded and or has a ferrite bead....it to try to remove or keep out unwanted noise from entering the ODAC or circuitry in any way....either coupled or induced or coming from inside on the power or data lines.

 

sources for errant noise are

 

1. From inside the PC, induced usually via radiation.

2. RFI or EMI into the cable outside of the PC, from a stong magnetic source, electrical source ac , etc...

 

there is no way this type of interferance would normally affect the digital bits from the pc to the dac....it would have to really be somthing very powerful to negate the full amplitude of the digital bits....or interfere with the timing between  bits.

 

if your envionment is fairly 'clean' you could use plain wires without shielding or grounding on one end....and all would be fine.

 

using a ferrite bead vs no-ferrite bead should not attenuate any of the actual content of those difital bits..there is no real way that a ferrite bead to remove these bits which if it could could then affect the downstream sound....

 

a ferrite bead is a passive device, it just is there....and when unwanted AC comes along...it help reduce or remove it from getting into the ODAC etc....so other wierd stuff wont happen...

 

Alex

Ah, I see. But, seriously, since when did anyone but a student talk of RF as AC? If you say 'AC' then no one is going to understand that you mean anything other than low frequency AC from power rails etc. After all, chokes/beads block high frequencies, not what is commonly understood when one says 'AC'.

if you dont understand it, then you dont understand it...so the ignorance keeps on going and people guess and make incorrect assumptions....ac circuit theory and dc circuit theory.....two seperate worlds but intertwine.....its very, very basic but to many its really confusing...take some time and try to understand the differences etc..

 

I am years out of the formal college days but am a student for life....

 

and I am still learning....

 

Alex

So... My Odac sometimes crashes when I plug other things into the wall.. that's always cool.

It used to crash when I would change the speed setting on my fan too. I wasn't sure what to blame and it didn't/doesn't bother me enough to complain. I just figured I'd see if anyone else had a problem like this or knew why it happened.

 

Is it a standalone ODAC or an ODAC+O2 combo? What does "crash" mean in this case?

You're having power problems.  Pick up an automatic voltage regulator of some sort and plug the device powering your odac into it.  That should fix your dropouts.

Yup, sometimes mine will cut out. Not very often but it's usually when i'm turning something on or off, or switching something on my comp. I've had my ODAC since they first came out and it's still going strong at over 1500 hours of use. 

 

~M

 

+1

 

I have had this problem two or three times over a period of eight months or so (not once a day) with a Behringer UCA-222. I never considered reconnecting it, but rebooting has restored the audio. Although I haven't had a similar problem on the PC with the ODAC, I shut it down every night, a process which tends to hide some O/S defects.