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My first Omnia ONE question

Waiting on my second e-mail from tech support. Probably won't hear anything for a couple of days since it's the weekend.

I have plugged some good headphones into the front of the Omnia1, and heard no distortion to my ear. I'm planning to run some low-frequency test tones through the unit this weekend to see if I can pinpoint a frequency range where the distortion is occurring.

fm-engineer: I really like that Cosmic preset too. Not sure how the One's version of Cosmic stacks up against the 6's version, but it is definitely quite different than the other presets in the One. We have to deal with a lot of hypercompressed material too, so finding a preset that handles this material well is important to me. Cosmic does that job pretty well thus far.
 
I have plugged some good headphones into the front of the Omnia1, and heard no distortion to my ear.
Click to expand...

That may indicate that your problem is not with the Omnia but some place downstream. What you heard in the headphones is the processed signal (minus composite clipping).

Poor or distorted audio is not always the the processor's fault. An exciter losing AFC lock or a bad SWR will also discolor audio.
 
tjm_pro said:
I have plugged some good headphones into the front of the Omnia1, and heard no distortion to my ear.
Click to expand...

That may indicate that your problem is not with the Omnia but some place downstream. What you heard in the headphones is the processed signal (minus composite clipping).

Poor or distorted audio is not always the the processor's fault. An exciter losing AFC lock or a bad SWR will also discolor audio.
Click to expand...

Yes. There is also a composite STL in the mix there too.

Quite a few variables to check out.
Do you have an engineer to *really* go through the system to make sure the chain from STL to transmitter is OK?

-C
 
fm-engineer said:
The cosmic preset is my favorite, and I see it quite often dialed up at stations. C. Gould has an even better sounding preset called rock smooth. I have installed it on seven stations this past month. It handles hypercompressed material even better than cosmic.
Click to expand...

Glad it's working for you!

I've been seeing a lot of downloads of that preset from my website, but only heard feedback from one user until you chimed in...so that makes two happy people that I am aware of!

One of these days I'll have to get my hands on the Omnia One so I can make some customized (CGould-ised) presets for that one too. 8)

The preset is spreading! ;D

-Cornelius
 
Oh yeah. Our engineer is great. He just went through everything, though. So this is just weird to me! :p
 
cgould said:
fm-engineer said:
The cosmic preset is my favorite, and I see it quite often dialed up at stations. C. Gould has an even better sounding preset called rock smooth. I have installed it on seven stations this past month. It handles hypercompressed material even better than cosmic.
Click to expand...

Glad it's working for you!

I've been seeing a lot of downloads of that preset from my website, but only heard feedback from one user until you chimed in...so that makes two happy people that I am aware of!

One of these days I'll have to get my hands on the Omnia One so I can make some customized (CGould-ised) presets for that one too. 8)

The preset is spreading! ;D

-Cornelius
Click to expand...

I'd like to see some for the -3fmt as well...
 
Everything can check out ok...but...

What brand of STL? Digital? Analog? Composite? perhaps I missed the answers to this...
 
Sgeirk said:
Everything can check out ok...but...

What brand of STL? Digital? Analog? Composite? perhaps I missed the answers to this...
Click to expand...

It's a composite STL. One of the big manufacturers. Recently refurbished to factory specs.
 
I have a correction on my original thought that the bass distortion was only below 100 Hz. It actually appears to distort as high as middle C, 440 Hz. There does not appear to be any distortion beyond that point.
 
Taking a stab in the dark...impedance mismatch somewhere along the way, or a transformer or capacitor issue in the transmit end of the STL??? could be receive end, for that matter....I'd start by finding other STL units to try...and see if that clears the issue.

Regardless of the box checking out ok, I've heard issues where bass causes issues with certain brands of STL's...replacing transformers and caps and beefing them up, can really help a composite STL be more competitive. But, that's just a rumor.

Assuming that you may be running a DIGITal exciter from a major brand name that starts with an H, find a temporary analog unit and see if that helps.

Any interference issue on the STL freq? Run a spectrum analyzer at the receive end, and kill the xmit side. All are are long shots, fairly involved, but worth a try.

FM is black magic, sometimes, good luck.
 
Got yet another update. What I had perceived as distortion actually appears to be NOISE. Killed the audio tonight and still heard this "gargling white noise" in the signal, which I have been describing all along. Killed the power to the Omnia, and the noise went away. Plugged it back in, and the noise returned.

For those of you playing at home...my Omnia is located at the studio before a composite STL. Trying not to give away too many brand names but that should cover some of the bases.
 
OK.. Now here's the question of the week for ya. What happens if you unplug the audio going INTO the Omnia One? If the noise goes away you've most likely got some noisy op-amps or something before the Omnia. Good luck!
 
OKCRadioGuy said:
OK.. Now here's the question of the week for ya. What happens if you unplug the audio going INTO the Omnia One? If the noise goes away you've most likely got some noisy op-amps or something before the Omnia. Good luck!
Click to expand...

One good way hear (and measure) what a composite STL is being fed is to take a stereo monitor to the studio and plug the output of the stereo generator into the composite input of said monitor.

Dr. Bob
 
remove the input audio to the omnia, then listen thru the headphone jack on the omnia ,see if you hear the noise.If so,you have isolated it to the omnia or a source it is plugged into.If not the noise is coming in from the source audio.Is the Omnia plugged into a UPC?
 
OKCRadioGuy said:
OK.. Now here's the question of the week for ya. What happens if you unplug the audio going INTO the Omnia One? If the noise goes away you've most likely got some noisy op-amps or something before the Omnia. Good luck!
Click to expand...
Dr. Bob said:
OKCRadioGuy said:
OK.. Now here's the question of the week for ya. What happens if you unplug the audio going INTO the Omnia One? If the noise goes away you've most likely got some noisy op-amps or something before the Omnia. Good luck!
Click to expand...

One good way hear (and measure) what a composite STL is being fed is to take a stereo monitor to the studio and plug the output of the stereo generator into the composite input of said monitor.

Dr. Bob
Click to expand...
menotti1 said:
remove the input audio to the omnia, then listen thru the headphone jack on the omnia ,see if you hear the noise.If so,you have isolated it to the omnia or a source it is plugged into.If not the noise is coming in from the source audio.Is the Omnia plugged into a UPC?
Click to expand...

All good things to do!

I believe you told me privately that the Omnia is on a UPS...that could be causing some issues too. See if the noise persists without it.

Try what these guys said, and the suggestions I sent during our off-list conversations, and let us know what you observe.

Notice how we keep coming back to the "Brand H" unit. Many of us have chased our tails over the years with weird issues with those things.

You mentioned having issues with lightning damage over the years - with that in mind, you CAN'T rule ANYTHING out that predates the Omnia....It looks to me like something is dying-or has died. It could be a zapped capacitor or Op-Amp that is buried somewhere in the gear isn't playing nice anymore.

Definitely looking like some tests without the main transmitting chain in the mix are in order...alternate STL's, Exciters, etc.

Anyway...what all of us threw at you is a LOT to pull off....let us know what you and your engineer find!

-Cornelius
 
I would tell your engineer to conduct an ole fashioned proof on the FM air chain. What happens when you unplug the composite cable from the back of the Omnia? If you hear the noise on the dead-air signal, the problem is down stream from the Omnia.
 
fm-engineer said:
I would tell your engineer to conduct an ole fashioned proof on the FM air chain. What happens when you unplug the composite cable from the back of the Omnia? If you hear the noise on the dead-air signal, the problem is down stream from the Omnia.
Click to expand...

Agreed!

We're all beating around this bush, but this really calls for putting the processor in 'proof' mode, and do an end-to-end tone & harminic distortion sweep through the entire system (with the tone sweep originating at the board, and measure THD & freq response at the output of each device until you find the unit spitting out the distortion).

As fm engineer calls it: an ole fashioned proof. 8)

This will take two people, and an entire overnight to do, but it's the only way to track this bugger down!

-Cornelius
 
I can't believe that a UPS could actually be putting this noise into the unit! We just got a new one, too!

I'll have to check it all out. Thankfully we now know that the noise is coming from something within the studio. It's a long and bumpy ride up to the transmitter. Not fun.

Updates coming this afternoon...
 
Found the noise.

Our RDS subcarrier. It's making about 30 db of noise within the audible spectrum. Unplugged the RDS and the signal was crystal clear.
 
Was able to turn the noise down with the gain control on the Omnia's SCA input. But the noise is still there. Looks like it may be interfering with another one of our boxes.
 
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