xyrium

Well, I do still stand by my recommendation for these. They have been quite nice: https://www.amazon.com/gp/product/B00FZ1362S/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 If you need adjustability of course.

Ok, update. I opened the case on the DAC9 and started poking around with my MM for continuity to ground. The chassis ground lug and the unit's receptacle ground are intact. However, using either the receptacle ground or the chassis ground, I do not obtain continuity to the USB port shell, which is metal. More oddly, I DO obtain continuity between the chassis ground or receptacle ground and the positive lugs on the XLR and RCA outputs. Why would the hots be grounded? Does any of this sound odd to folks here as well? Thanks!

Looks like some nice choices, though I'm unfamiliar with anything in the list other than the Oppo. I owned the HA-1 and it was quite a nice piece of gear. It's accuracy was unquestionable, though I prefer a more coloured sound given the variety of music and recordings that I listen to. So, out went accuracy, and in went a Teac UD301 and Nuprime DAC9. Regardless, that new Oppo looks nice, and would probably be my first choice, especially at that price.

Thanks Middy. I think the HumX is getting the job done, and I'd rather not mess with the USB signal. I've read up on the CMX though, and it does seem nice if I needed multiple device filtering. My Fluke is a fairly new 87 model, and it's measuring 0 to negative values on DC on the outlets, so I doubt offset is a problem. While not the top of the line, the 87 is still a fairly decent unit. So, it looks like I need to suck it up and keep the HumX in line, or swap the DAC9 for a new one (as they've offered, unless is a design defect). Thanks for everyone's help! I'll keep the thread updated if there's a change!

Holy moly, I'll try this today. I've been allowing this to slide this week since I put a HumX inline with it's power cord. Edit: I couldn't wait to try this, so I tried electrical tape, just 1 wrap of Scotch Super 33+ and it wouldn't fit. Then I tried Teflon tape, but the noise still existed. It's not overbearing, but it's clearly audible. Reinsert the HumX and it goes away. Everything is plugged into the same out via a power strip, Tripplite Isobar. ype of the USB B connector. It 'looks' as though the shell connector is crimped onto the frame of the DAC, which is grounded to safety earth. That's where the ground loop comes from. The Teac uses a plastic shell, which insulates the USB cable shell from the frame and safety ground. This is also the practice for Grace Design m920 USB connector, and just looked at Yggdrasil, hard to tell, but looks like a layer of plastic around metal too. From here? Return the Nuprime as unsuitable or buy an Intona or just keep using the Teac.

Are you using ASIO drivers?

I certainly agree that matched pairs are indeed intended to be as close to each other electrically than anything else. However, I'm of the camp that believes that the electrical differences are the audible ones when it comes to anything other than speakers. While you can match potential plate currents in matched pairs as their resistance would be similar, you can also match their potential for gain (capacitance?). Thus, get them electrically close and you would be audibly matched. Again, just my opinion, as psychoacoustics are largely at play in this industry. To me, this explains why tubes from the same manufacturer (especially if you buy direct, and not from someone like TAD, Ruby, etc.) will vary slightly in sound, and thus, electrical values, even within the same batch of the same model. The rest, well, I don't hear anything beyond 12kHz at my age probably, so it doesn't matter.

I'm fairly certain that the tolerances on tubes is rather loosely "defined" if anything when you're pricing factory stuff. That's why tube retailers sell matched pairs (triodes, and gain from what I've experienced) for a marginal premium. The same can apply for preamp tubes such as the 6SN7. It's these minor (sometimes significant) differences that can scertainly change the sonic characteristics of a sensitive circuit IMO.

Hmm, hadn't tried that.

Yep, that's what I'm assuming, but only happens on one device and goes away with a ground lift. Exactly right, and thus why I'm baffled by the problem, unless there's something going on inside that new DAC.

Whoa, very nice.

That PSA is quite interesting. I'll have to keep my eyes on it. I'm sure I'll be *upgrading* within a year with the way things go in this hobby anyway.

Hey Panelhead, I exchanged a few emails with them to finally learn that only their Red line has an analog volume control, and the Scarlett and Clarett lines do indeed truncate bits at low levels.

So, I have a Focusrite 2i2 that I use for connecting a Mic and Guitar and producing through simulators, and I have a Teac UD-301 strictly for listening to WAVs. Both of them are dead silent, no buzzing, hissing, or any other annoyances. I then purchase a Nuprime DAC-9, thinking I would improve on the excellent performance of the Teac (regardless of its digital volume). Unfortunately, I've been through hell and back trying to eliminate the buzz that the new unit exhibits once a USB cable is connected. I've gone through isolation transformers on the power cord, I purchased a standalone PCIE USB card, tried a new Pangea CU USB cable, updated drivers where possible, disconnected fans within the PC chassis, unplugged all drives but the OS (Win 10), and I pulled out my video card and ran off of built in video on the MB. Then I connected the unit to a laptop running on battery. That last step eliminated the noise. Plugged in the power supply and the noise returned. So, I decided to reconnect it to my PC once again, but I plug it's (the DAC) power cord into a cheater plug (removes ground), and the noise disappeared. So, sorry this was long, but no other device needed a ground lift, so I'm of the opinion that there's an issue with the new DAC. Does this sound about right? Thanks!

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