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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: TNJazz on November 23, 2005, 08:14:06 AM
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OK, this is weird. I searched and didn't find the answer anywhere so hopefully someone knows what's up?
I just got a UA5 back in the mail from busman2 (thanks!) and I started testing it last night. All seems fine, except the digital stream doesn't seem correct. It passes signal, but only at 48kHz (apparently). No adjustments to the front panel of the UA5 would alter this. It seems to me that switching it to 44 would switch the destination device to 44 as well (in this case, my R500) but it doesn't.
So I'm a little confused. Am I doing something wrong here? The stream from the UA5 should lock the sample rate on the destination device, shouldn't it?
Dirk
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this is probly obvious but, do you have the "ADV" switch on the back in the right position??
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this is probly obvious but, do you have the "ADV" switch on the back in the right position??
That shouldn't effect the sample rate, only the Bit rate. The sample rate should still be adjustable by switching the knob on the front. Are you recording to DAT/JB3 or laptop/pda? How are you testing the sample rate?
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ADV has no effect on the stream (at least not visibly). I'd be running to a laptop via USB anyway and I could honestly care less about the digital outs, but it seemed like a good idea to do anyway. No JB3 or microtrack thingys in my future, so no big deal really. Just really puzzling and it doesn't make sense since we're talking about DIGITAL...! It's almost like it's an analog stream, but I can't change the sample rate.
I'm going coax out of the UA5 into my R500 for testing. The deck locks to the coax signal (and freaks out if I turn off the UA5 of course) but changing the knob from 48 to 44 on the UA5 has no effect on the sample rate locked on the R500 - it stays at 48k. Flipping the ADV switch back and forth doesn't change anything either. It's like the coax output sends out a raw 48k stream, no matter what the sample rate set on the UA5...
Weird. Anyone have any idea why?
Dirk
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I'm going coax out of the UA5 into my R500 for testing. The deck locks to the coax signal (and freaks out if I turn off the UA5 of course) but changing the knob from 48 to 44 on the UA5 has no effect on the sample rate locked on the R500 - it stays at 48k. Flipping the ADV switch back and forth doesn't change anything either. It's like the coax output sends out a raw 48k stream, no matter what the sample rate set on the UA5...
Are you stopping and re-starting recording on the R500 between sample rate changes? I suspect once the R500 locks on, it won't change SR on the fly without stopping and restarting the recording. Try stopping the recording, switching the SR from 48k to 44.1k and re-starting the R500. I suspect it will lock on at 44.1k (if it has this capability, which I assume it does).
As for the ADV switch - you won't see any change on a 16-bit recorder unless you compare the recordings. With the ADV switch OFF, the R500 records the 16-bit signal output by the UA5. With the ADV switch ON, the R500 takes the 24-bit signal from the UA5 and truncates the least significant 8 bits (or maybe the R500 truncates 4 and SBMs the other 4, I forget the specs on this particular unit). At any rate, the end result on the R500 is still 16-bit, even though the UA5 outputs 24-bits, but the 16-bits captured contains different data than a pure 16-bit stream from the UA5.
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I've tried it both on the fly and stopping/starting the R500. Even turned it off, turned the UA5 off, and then turned them both back on. UA5 set to 44, hit record and the deck locks coax, but at 48k.
Fully aware of the 24 bit truncation by a 16 bit device of course. Just stating that I see no obvious difference in the metering, so that further evidences that the ADV factor doesn't enter into it at all.
I'm really baffled by this. I'm going to go home and do this again tonight, just to make sure I'm not crazy. Maybe I'll take pictures this time. Hopefully the aliens won't erase them from my digital camera.
Dirk
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I've tried it both on the fly and stopping/starting the R500. Even turned it off, turned the UA5 off, and then turned them both back on. UA5 set to 44, hit record and the deck locks coax, but at 48k.
Fully aware of the 24 bit truncation by a 16 bit device of course. Just stating that I see no obvious difference in the metering, so that further evidences that the ADV factor doesn't enter into it at all.
I'm really baffled by this. I'm going to go home and do this again tonight, just to make sure I'm not crazy. Maybe I'll take pictures this time. Hopefully the aliens won't erase them from my digital camera.
Dirk
Perhaps it's worth an email to Busman? Perhaps the sample rate section of the board itself isn't modified but perhaps some other part of the board might not be fully functional without some connection or something. Not an accusation by any means, I love my BM2p+ UA-5...no problems here.
What happens if you change the sample rate and record to the laptop? Does the rate change then? Like if you open a new Soundforge (or whatever) window, you record to 44.1 or 48 KHz but does it show it as such?
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I know this seems stupid but did you check the analog digital switch on the front panel also? Let me know if you continue to have issues so I can help you resolve them. If there is an issue with the A/D chip it could cause this. Either way let me know.
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yup, checked all the switches. Doesn't that button just dictate input though? All I'm doing is plugging a mic in the front panel, so I assume it should be set to analog?
Like I said it's not really a big deal, since I don't really do much 2 track taping anymore and I can't remember the last time someone hit me up for a patch. I just found it to be odd that it works, but seems to be working contrary to the laws of digital streams!
Dirk
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I just found it to be odd that it works, but seems to be working contrary to the laws of digital streams!
I wouldn't assume anything based on the R500 SR lock light and the levels not changing (not sure why they would?). Without further testing - could be a range of causes at this point, we really don't know.
I would test 16/44, 16/48, 24/44 and/or 24/48 output from the UA5 to a device capable of capturing all of the above bit-depth/sample rates and confirm in an audio editor whether the captured streams are, in fact, as expected.
I'd also test the actual content recorded on the R500 to determine whether it is, in fact, 48k, or whether it's actually 44.1k and either <a> the display is wrong, or <b> the WAV header is written incorrectly.
And I'd also try feeding the R500 the same bit-depths/sample rates from another device to see if it behaves the same way.
'Course, that's a fair amount of testing, so if it doesn't really matter to you...
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wouldn't assume anything based on the R500 SR lock light and the levels not changing (not sure why they would?).
They don't, and they shouldn't. Just a bit of extraneous information I really didn't need to add. I guess my reasoning was that perhaps since the digital stream wasn't locking, what I was somehow seeing was an analog signal. Obviously not the case though; just trying to troubleshoot from every possible angle.
I would test 16/44, 16/48, 24/44 and/or 24/48 output from the UA5 to a device capable of capturing all of the above bit-depth/sample rates and confirm in an audio editor whether the captured streams are, in fact, as expected.
Already did this and it all checks out fine (laptop via USB).
I'd also test the actual content recorded on the R500 to determine whether it is, in fact, 48k, or whether it's actually 44.1k and either <a> the display is wrong, or <b> the WAV header is written incorrectly.
R500 display changes on analog, and on digital input from another device (My Nuendo box, which is my home PC sound card) when the sample rate of the source file is changed. Not sure how to test the header to verify it's correct or incorrect.
And I'd also try feeding the R500 the same bit-depths/sample rates from another device to see if it behaves the same way.
Also done. Although I did not send a 24 bit sample out of the Multiset into the DAT. Didn't feel there was a need for it.
Dirk
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I would test 16/44, 16/48, 24/44 and/or 24/48 output from the UA5 to a device capable of capturing all of the above bit-depth/sample rates and confirm in an audio editor whether the captured streams are, in fact, as expected.
Already did this and it all checks out fine (laptop via USB).
Sorry, I wasn't clear. I meant via coax output, not USB, in order to duplicate the precise signal path used when outputting to the R500.
I'd also test the actual content recorded on the R500 to determine whether it is, in fact, 48k, or whether it's actually 44.1k and either <a> the display is wrong, or <b> the WAV header is written incorrectly.
R500 display changes on analog, and on digital input from another device (My Nuendo box, which is my home PC sound card) when the sample rate of the source file is changed. Not sure how to test the header to verify it's correct or incorrect.
Easiest way: simply play back the WAV. If it sounds the wrong speed, then this suggests the WAV header's SR does not match the actual SR of the bitstream. One may set the WAV header to the correct SR by opening the file in an audio editor and setting the new SR (note this is different than sample rate conversion - it's simply changing a value in the WAV header, not changing the SR of the actual data).
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Gotcha. After I re-read your post I realized you probably meant coax out. I'll run the UA5 into my multiset this evening and see what happens.
As for the playback, no issues with pitch or anything so I would assume the header is correct.
Dirk
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Gotcha. After I re-read your post I realized you probably meant coax out. I'll run the UA5 into my multiset this evening and see what happens.
Checking the block diagram, I don't see any reason why a digi-modded UA5's coax output would differ from the USB, but...block diagrams often aren't terribly useful since they include so little detail (by design, of course). Worth testing, at any rate.
As for the playback, no issues with pitch or anything so I would assume the header is correct.
The WAV header SR probably matches the actual data stream SR, then. So I think there are two possibilities here:
<1> the R500 recording is 16/48 even though the UA5 was set to output 16/44
<2> the R500 recording is 16/44 even though the R500 indicated it was locked to 48k
I'd transfer the R500 recording to computer and check the whether the SR is 48 or 44. Any audio editor should be able to tell you. In Adobe Audition, it's in View | Wave Properties.
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Could be something as simple as the knob which changes the sample rate not operating correctly...hopefully
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I borrowed a w-mod UA-5 to run into my PMD 671 for a show. Going line in from the 1/4' jacks in the back, I notice that the output level is controlled by the "Output' knob on the front of the unit. So, should I run that knob cranked up to the max or in the middle. I've never run the UA-5, so any advice would be appreciated.
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I think you want that knob all the way down.
With all the issues, it does sound like the Sample Rate knob may be bad. If that's not working, then most likely there's a broken solder joint or something similar on the inside.