TA-100 USB failing

[vt]

I bought my TA-100 back in March, and until now had an external DAC running into it, so my USB cable (Audioquest Carbon) was plugged into the DAC. DAC is being replaced, so I plugged into the USB input on the TA, and there seems to be a malfunction. First, it feels a little loose and wiggly. But the real issue is that sometimes I get no sound at all, and the receiver doesn't even recognize the source. Other times, there is volume, but it's seriously reduced. Then it suddenly works for a while after cycling through other inputs, like switching to the LDAC receiver which is connected by coax. I'm wondering if it's the USB or possibly even the internal DAC, because what seems to reset the USB is switching to the coax input, then returning to the USB, which I find pretty weird. Have tried another cable, same results.

Has anyone ever heard of anything like this with the TA or other Emo components?

Thanks,

Bryan

[cawgijoe]

Bryan....have you tried calling Emotiva support?

[KeithL]

While we've had a few incidents of failed USB inputs on the TA-100 it would be really unusual to have one become intermittent.

(So, while there could be something like a bad solder connection, it's uncommon.)

There is also nothing that would obviously account for "reduced volume".

(With digital audio a "bad connection" usually results in no sound, or dropouts, but not clean sound at reduced volume.)

Unfortunately USB connections in general, and the original "big square USB printer connector" in specific, aren't especially solid or secure.

As a result, many USB cables fit loosely, and fall out rather easily.

(They often feel "loose and wiggly" but usually still manage to work OK.)

(Which makes it seem like an especially bad choice for storage media like disc drives.)

I would be inclined to try a different cable.

(And don't spend so much on the next one... it's not going to sound any different.)

Our Emotiva branded USB cables are quite nice - and a steal at $7 for two-meters on closeout ( emotiva.com/collections/accessories/products/musb

(Amazon Basics cables are also quite nice - and they also use nice gold plated connectors.)

Of course, if it does turn out to be the input itself, we'll be glad to fix it.

Jun 14, 2021 21:24:12 GMT -5 vt said:

I bought my TA-100 back in March, and until now had an external DAC running into it, so my USB cable (Audioquest Carbon) was plugged into the DAC. DAC is being replaced, so I plugged into the USB input on the TA, and there seems to be a malfunction. First, it feels a little loose and wiggly. But the real issue is that sometimes I get no sound at all, and the receiver doesn't even recognize the source. Other times, there is volume, but it's seriously reduced. Then it suddenly works for a while after cycling through other inputs, like switching to the LDAC receiver which is connected by coax. I'm wondering if it's the USB or possibly even the internal DAC, because what seems to reset the USB is switching to the coax input, then returning to the USB, which I find pretty weird. Have tried another cable, same results.

Has anyone ever heard of anything like this with the TA or other Emo components?

Thanks,

Bryan

[vt]

Thanks guys, I appreciate the information. First, yes I did reach out to support, and was told to send it in. I get what you're saying Keith, and I thought it might be a solder connection but don't know enough about the small details to be sure. I have another generic cable and it had the same results.
The odd thing is, last night I plugged in and everything was fine. Tonight, same thing. Believe me, previously I unplugged, replugged, cycled through inputs, turned the unit on/off, tried every possible combination of sources (macbook, iphone, pixel 3), and had the same result. I'm pretty decent at troubleshooting, eliminating possible causes (I'm a carpenter so everything looks like a leaky roof to me), and it seemed the usb port was the only constant. What I cannot understand is how things suddenly returned to full functionality. Sounds excellent, tonight was Thelonius Monk (Monk's Dream) and Sun Kil Moon (Admiral Fell Promises, great classical guitar), with a dash of Fleetwood Mac Rumours (testing some new cans and it's one of my favorite reference albums).
I'll continue to test it and see if something changes, because I'm probably going to sell the unit and replace it with some new Emotiva gear very soon. Love the sound of the TA, it's just fantastic for someone at my level.

[KeithL]

Hi guys.

The bottom line is that the USB inputs on the PT-100 and TA-100 are actually pretty simple.

A USB audio input is NOT complicated like an HDMI input...

And are not subject to the same huge collection of compatibility issues...

And those devices are using USB Audio Class 1 - which is very widely supported.

In troubleshooting terms it's really unlikely for USB audio interface chip to die like that...

When they fail they usually stop altogether...

And, likewise, sources are rarely intermittent with specific hardware devices.

(In general they'll work or not.)

This points in the direction of:

1) an intermittent connection between the source and the PT-100 or TA-100
   - which could be a bad or shorted cable

   - or could be a cable that's too long

   - or could be a cable that's odd in some other way (some "audiophile" USB cables don't follow the actual USB spec)

   - or could be a shorted or loose cable connector or a bad solder connection inside somewhere

2) something on the computer

   - this could be a bad setting in the output drivers

   - it could be a conflict with some other program that takes over the audio on the computer (like Skype or Zoom)

   - it could be some other program loading the computer down (things like A/V software updates can are known to sometimes cause audio or video dropouts)

You can test the cable easily enough by trying a different one.

It's also easy enough to try a different computer - which would rule out any possible software issues.

You can connect pretty much any computer and it should just work...

And, since you don't have to install anything like drivers, you can borrow a computer for a few minutes without having to install stuff on it.

Any smart phone or tablet that has a USB output and support for any sort of external DAC should work as well.

(Some tablets will work with external DACs and others won't.)

Note that data from the USB input passes THROUGH the same circuitry that handles the Coax and Optical S/PDIF inputs.

So, ONCE YOU'VE RULED OUT THE CABLE, AND COMPUTER, AND THINGS LIKE A LOOSE CONNECTOR, next try those inputs.

If the Coax and Optical inputs work then any problem inside the unit MUST be in the main USB interface chip or one of a few parts associated with it.

And, if all three don't work, then the problem is in the main part of the digital input circuitry.

(And, in this case, if any of those problems has occurred inside our unit, it's going to have to come in for repair either way anyway...)

Jun 16, 2021 20:34:51 GMT -5 vt said:

Thanks guys, I appreciate the information. First, yes I did reach out to support, and was told to send it in. I get what you're saying Keith, and I thought it might be a solder connection but don't know enough about the small details to be sure. I have another generic cable and it had the same results.
The odd thing is, last night I plugged in and everything was fine. Tonight, same thing. Believe me, previously I unplugged, replugged, cycled through inputs, turned the unit on/off, tried every possible combination of sources (macbook, iphone, pixel 3), and had the same result. I'm pretty decent at troubleshooting, eliminating possible causes (I'm a carpenter so everything looks like a leaky roof to me), and it seemed the usb port was the only constant. What I cannot understand is how things suddenly returned to full functionality. Sounds excellent, tonight was Thelonius Monk (Monk's Dream) and Sun Kil Moon (Admiral Fell Promises, great classical guitar), with a dash of Fleetwood Mac Rumours (testing some new cans and it's one of my favorite reference albums).
I'll continue to test it and see if something changes, because I'm probably going to sell the unit and replace it with some new Emotiva gear very soon. Love the sound of the TA, it's just fantastic for someone at my level.

[vcautokid]

Yes especially high end USB cables can be problematic too. I helped a customer, similar issue bad USB cable. I am not naming names either, try another USB cable just to be sure. A cheap one lying around is fine. No guarantees but try it anyway.

[boomzilla]

Jun 15, 2021 9:19:57 GMT -5 KeithL said:

...I would be inclined to try a different cable. (And don't spend so much on the next one... it's not going to sound any different.)...

Amen, brother!

[vt]

Keith, you are a great explainer, and I have read many of your posts prior to finally chirping in here this last week, and learned quite a bit. Thank you for your generosity.
I should have made a little chart on all this, because I think I may have confused some of the details regarding combinations. This evening I queued up some background music while I was making dinner, on the Pixel, which I bought used exclusively as a streamer, and which always worked just fine til all this started, and as I said in my last post, magically resumed function last night. Well, that was short lived, so I went the rounds again, and realized running through my M1 Mac, there is no problem. I've concluded the problem is not in the cable, or the onboard DAC (coax and opt work fine), or even the USB. The issue is the port on the Pixel 3, and on the iphone I've concluded that there is a compatibility issue in the chain, probably due to the converter, which works fine on my portable DACs but apparently not in this setup. But the Mac performs flawlessly. The final test will be when my Asgard arrives in the next couple of days, and I will patch it into the TA and then run the USB cable into it and run through the sources again, and see if I can verify my assumption. I'll also just run it as a headphone amp and see what happens. This should shake out all the variables and give me a clear answer. I'm really relieved to see that it's most likely not the USB on the TA that's the issue. Now I just have to find a new device to stream from. I'll keep the Carbon cable but will give some time to critical listening and if what all of you are saying is true to my ears, I'll ditch it and buy a $20 cable and pocket the Ebay money to help pay for my obsession. any advice on a tablet/phone solution to stream Amazon/Tidal is welcome, and I once again thank you for all of your input.
The next thing I'm going to do is put the TA up for sale, because I want to replace it with another Emotiva amp, especially since I'm committed to an external DAC which will have all the inputs I need. I honestly don't see a transport (whatever) or a phono in my future, I'd rather spend the money on a pair of GR-1sm and then finally, I promise, stop and just listen to music, haha.