The All Purpose Advice Thread

@songmic do your USB cables have ferrite chokes on them? I was picking up radio on one of my USB cables a while ago. Didn't know it was physically possible for the noise to get transmitted over, but it did.

 

Sounds like a typical ground loop. Are all of the power cables on the same outlet? If you're spanning two outlets it can be an issue. Also, USB will transmit power and is grounded so it can create a ground loop from the computer. There really are so many variables but the simple solution is to put everything on the same power strip or at least outlet, keep analog cables away from power cables, especially RCA (balanced doesn't matter so much), and if that fails try putting a power conditioner like a Furman or the Emotiva CMX-2 and see if that helps.

Also, the best thing you can do is ditch USB and go for SPDIF coax or optical. Optical from a good source might be your best bet as it will provide galvanic isolation.

 

For <$300 just pick up a cheap pro interface like a Steinberg or Focusrite. They have XLR line outs for your amp. The Modi 2U is fine, mostly neutral; you'll need the appropriate RCA-to-XLR cables and I recommend a filtered power strip for it as well if you don't have one already.

Do not buy the multibit Modi for mixing or mastering.

 

You toggled the input to BNC and coaxial but did not actually provide an input for such? Don't assume the hum is isolated to the USB input, it's more likely that it's only present when there is signal being fed to the DAC in some way. Is the hum persistent or intermittent? When did this start?

 

I'd grab something with both quality like the Modi, but a wide array of inputs and outputs, @k4rstar thanks for listing such a product, @Story that would be my choice as well [maybe not that exact brand but an interface with a modi 2U]

Also @Story what part of hilton head are you in? I'm near Myrtle my self, your most likely the only local I've met here

 

The fact that the XLR interconnects eliminate the noise (or lower it enough so you can't hear it) tells us it is "common-mode noise". Look here:

http://www.prosoundweb.com/topics/analog/dirty_ac_power_where_to_lay_the_blame_for_noise_problems/

I got around a problem like this by getting a quality isolation transformer (Topaz 91002-31) and a quality TrippLite PS power strip. I plugged everything into the power strip and then I plugged the power strip into the isolation transformer.

 

No ferrite chokes on my USB cable, they are USB PYST.

Yes, they are all on the same grounded power strip plugged into a grounded outlet. The Mjolnir 2's power cable is physically away from the XLR and RCA cables, they don't touch. I will try a power conditioner or S/PDIF or optical inputs.

The noise is persistent. I hadn't noticed before this because I was using Gungnir Multibit's XLR outputs all the time with Mjolnir 2. I first noticed it after trying its RCA outputs the first time with Torpedo 3.

 

@songmic Same issue here, I think it's just a function of using single ended cables. Posted about it here: http://www.superbestaudiofriends.org/index.php?posts/142547/.

Further color:

• I use 75ohm coax from player to Yggdrasil, no USB. Blue Jeans digital coax cable.
• My player's coaxial digital output is transformer isolated: http://audiopraise.com/vanityhd/overview.php
• Power cables into one conditioner.
• Power cables cross RCA at right angle.
• Amp not stacked on DAC.
• Didn't just happen with T3, also happened with a PrimaLuna amp hooked up to Yggdrasil via RCA.

 

This is random and if you don't want to answer don't feel the need, but I picked up a couple vinyls of a few of my favorite albums today to decorate a room.

I was kind of wondering how much a really good vinyl set up would cost? And in this case I mean good enough to sound worthy of Focal Utopias and a EC Aficionado amp (hypethetically / hopefully speaking).

I've focused all my research and auditioning on dacs and amps and never looked on the vinyl side so I'm a total noob.

I'm not even looking for products I don't want to waste your time, just like a general estimate for a player cost like 1k? 5k? I'll eventually do research on my own, but if you say like 10k I'll know just not to bother . Thanks in advance guys.

 

Lots of different approaches to system building when it comes to analog, many more variables at play then with a digital front end.

Fantastic answers here: http://www.superbestaudiofriends.or...equired-for-a-good-turntable.2957/#post-85834
http://www.superbestaudiofriends.org/index.php?threads/budget-vinyl-rigs.1462/

Since there's more than one approach even a ballpark figure isn't easy. You could be looking at ~$2k for a solid deck, ~$500-1000 for a cart and ~$800-1.5k for a nice tubed phono section. That is absolutely not to say cheaper than that would be no good, you could also build something for a fraction of those figures that you would still enjoy listening to more than a Yggdrasil, who knows.

Options in all categories open up if you shop used and have a little patience. The solid advice though is to figure out if the vinyl thing is for you or not, and then skip mid-fi tables altogether.

 

Thanks!

Dang that gives me a lot to think about. One of the reasons I really love digital is existances like Tidal really make it super easy to discover new music that sounds good (I'm also excited to get a Dac soon that hopefully will reveal a difference between Tidal Masters and regular).

Vinyl sounds super tempting and amazing, but the actual act of collecting the music sounds expensive over time vs something like Tidal. Thanks again for the links they're great. And I actually share a similar philosophy for headphones (as in I prefer skipping mid-fi like 500 dollar headphones and going straight from 100-200 dollar to 1000+ dollar instead of 600 dollar (like uh... Skip HD700 and go straight to HD800SDR from H600 I guess is an almost ok analogy?)

Anyway point is it sounds really good, but it doesn't sound feasible for me right now. But I'll keep an eye out to try a high end vinyl rig.

 

I agree with @cskippy, this sounds like a ground loop.

Maybe getting a Jensen Isomax XLR-to-RCA box to connect the balanced outs of the Gungnir Multibit to the T3 would do the trick.

 

Serious question here:

If everything is plugged into the same power strip, how could it be a ground loop?

 

I am not an electrical engineer so all this could be rubbish, but as I understand it you don't need a difference in ground potentials to hear a ground loop. Say you have a loop that goes power socket -> PC -> Gungnir Multibit -> T3 -> power socket. This is a physical loop in space and any magnetic flux enclosed by this loop can induce a ground current. A typical source of magnetic flux would be a nearby power transformer so often the current will be at 50/60hz. Because in an unbalanced RCA connection the ground being connected is audio ground you can then hear this. In an XLR connection the ground loop would be made by the cable shield which is supposed to be connected directly to chassis ground but not directly to audio ground so even if you induce a ground current it should not affect the audio signal (so long as your balanced equipment is wired correctly, which it sounds like the Schiit stuff is).

I believe a way to avoid the ground loop with unbalanced connections would be to entwine your RCA cable from the back of the T3 around the T3 power cable back to the socket and then across to the Gungnir Multibit power cable and wrap around that all the way back to the Gungnir Multibit RCA. Then do similarly with the USB connection between the PC and the Gungnir Multibit. The idea is to reduce the area enclosed by the ground loop and so lower the possible induced current. Of course you need some pretty long interconnects to do this. I don't know if anyone has been crazy enough to actually do this in practice.

 

Thanks for the help, guys.

I'm on the north end, maybe four miles after the bridge near Folly Field beach area.

Are y'all saying that I should get an audio interface and a DAC (Modi u2)?

Maybe I could get a UAD interface so that I could use their DSP plug-ins - would I need a separate DAC in conjunction to an interface? Or will am interface itself suffice for transparency and quality etc

Thanks again

 

I'm looking for a reliable pair of wireless IEMs for running. I'd like them to work with android os, stay in my ears, produce sound, and not break for a few years. I'd like to spend less than $150. All the reviews for stuff like this online are paid BS and say every pair of sports BT headphones will meet my requirements, but I have found this not to be true. Any recommendations/experiences appreciated. Thanks.

 

Occurs with multiple sources + RCA cables only strongly suggests to me that the RCA cables are picking up noise from something, Length of the cable matters little if the interference is very powerful or close enough to the cable. Possible sources of noise are either a power cables running in parallel (i know you indicated they are separated), transformers inside amps, or nearly anything broadcasting EMF. This is exactly why balanced XLR cables are used in pro envrironments.

If it is EMF on the cables, note that use of an Isolation transformer per @Garns works only if the transformer is far enough away from the source of the interference so that cables on both sides don't both pick it up. I speak from experience on this and I own a couple of the Jensen boxes as well as other isolation things.

Is there a reason not to just go with XLR cables and call it a day here?

USB cables can pick up the same types of interference, it doesnt matter what the brand is. You can buy a cheap USB with ferrite donuts from Amazon to test that out.

 

Passive XLR splitters that switch between outputs (versus ones that switch inputs) are comparatively rare. I have one of these which is very good but is not really cheap. You can also get it with a volume control which is more useful but costs even more.

I highly suggest that you start by trying a very inexpensive, unswitched Y splitter such as https://www.amazon.com/Hosa-YXM-121...qid=1498412407&sr=8-2&keywords=xlr+y+splitter. I use these in several places in my system and I don't find they affect sound much at all, although they do drop the input signal by some amount. I have not found that to be a problem with a good amp. These simply make much more sense than spending money on a switching assembly for outputs.

I tried MULTIPLE 'inexpensive' passive XLR switching solutions before going with the goldpoints. To me this is one area where you get what you pay for, the cheap ones sound really bad.

 

An update to my post above, as this point got me curious. With T3 knob maxed and Utopia on I did the following:

• Unplugged TV (already turned off)
• Unplugged Ethernet to Oppo
• Unplugged coaxial cable to Yggdrasil
• Unplugged USB cable in back of Yggdrasil (Mac Mini already off)
• Turned Oppo off
• Turned cable modem and router off (same room, different outlet, but likely same circuit)

Earlier today I tried shielded vs. unshielded power cables on Oppo and Yggdrasil as I had been using unshielded power cables recently. T3 has always had a shielded power cable. While doing so I moved the T3 to the floor, a couple feet away from Yggdrasil. Power cable nowhere near RCAs. I also tested when the central air was both on and off.

Nothing above did anything to change the hum, meaning I think the hum is just a function of the Yggdrasil being on and using RCA cables with a volume knob maxed or close to it. Haven't ever tried XLR out.

As a sanity check, I then tried the headphone out of my Peachtree integrated with volume knob maxed. Quieter hum than with T3 on hi Z setting with Utopia. With Utopia, low Z setting on T3 hums more quietly than hi Z setting (each with volume knob maxed).

Interestingly, when I turned the cable modem back on, I heard a couple pops through the headphones, but the hum didn't change.

In a few weeks, I may throw my Cardas power cables back on as a final check. They have a toroidal filter on them that "makes the ground leg look much longer than it actually is. This helps to eliminate noise on the ground leg." (Source: personal email with Cardas). I was using those power cables when I first got the T3, but it's been so long I don't remember ever testing for hum with nothing playing and volume maxed. I took them out a while ago as they seemed to roll off treble a bit when I compared to Shunyata power cables with the T3/Utopia.

 

Thanks for all your kind input, guys. What would I do without you.

So, now I'm convinced that this is a ground loop issue. Strangely, I haven't had this issue with my previous single-ended setups (e.g. Yggdrasil/ZDS, Processor 3/Stratus, etc.). Anyway, the ground loop explains why I'm not hearing any noise when XLR interconnects are used.

I've done some research and it seems that the best method (the most beneficial method from an audiophile point of view, i.e. to minimize compromising sound quality) is to use a ground loop isolation transformer.

Will something like this work?
http://www.jensen-transformers.com/product/ci-2rr/