Topic: ratshack digital signal converter testing :)

[johnw]

That's weird because I have done that and the levels over USB were lower by a few decibals than the same file recorded by JB3 and played back through Soundforge. Never did a bit test because I was just trying to get my SUV calibrated.

[dklein]

That's weird because I have done that and the levels over USB were lower by a few decibals than the same file recorded by JB3 and played back through Soundforge. Never did a bit test because I was just trying to get my SUV calibrated.

very weird indeed.  actually...shouldn't be possible.  And I can't come up with any reason why it would happen unless you're talking about the SUV measuring differently.  The wave files produced from USB and JB3 should be the same.  The SUV levels will be affected by the monitor function on the UA-5 because the SUV is driven from the analog output and gets messed up when the monitor button is on.  You actually get a double signal, slightly delayed.

[ChrisV]

Sounds good...well if they turn out to be bit for bit perfect then we definitely know the coax and optical out of the UA-5 are equal for sure too ;p

Anyways, I just started a quick initial test...will be a 1 hour test.   I even started the JB3's at the same time and it is kinda funny to listen to the JB3's you can hear them both make HD writes at the same time in sync too ;p
Popped on the phantom power to the mics 5 seconds into the recording and both are off and running.   

Looks like with the handy dandy "File Comparer" tool in Wavelab it should be rather easy to compare.   Will post results from initial test.   Keeping fingers crossed

[ChrisV]

I think it came back perfect.  Wavelab gives me the message "The two files have a different size, but the shorter one is exactly equal to the start of the longer one."   I think it got a little funky at the end one channel cut out sooner than the other on one of the recordings.   So I am gonna lop off a few samples off of both and retry

[ChrisV]

Yippie!   Yeah, just had to lop off one extra sample at the end from one file....dunno quite how that happened like that(probably due to the fact that I just cut power on the UA-5 to create the empty space at the end).   Anyways now I get "The two files ar exactly equal!"

So a very good sign the first test of 1 hour passed with flying colors.   I hope to do many many more hours of testing to before we come to the conclusion it is indeed bit perfect.  But this first test passed and if results stick it confirms 3 things:
A) Ratshack Converter is bit-perfect
B) UA-5 outputs coax and optical are indeed exactly the same
C) One of my JB3's was completely empty just formatted and the other one was 95% full...so no problems at all on the near full one with regards to writing to a near full disk.  I had an hour and a half left on it and used up an hour of that.   So only a half hour left(295 MB out of 19056 MB left).

[ChrisV]

Ahh woke up this morning and did another test.
I forgot to mention the first test was using AC power, and done at 44.1 khz.
This time I hooked up my 9.6 V RC battery pack to the Ratshack converter and did a quick new test(also at 44.1 khz) and it passed 100% again

[johnw]

That's weird because I have done that and the levels over USB were lower by a few decibals than the same file recorded by JB3 and played back through Soundforge. Never did a bit test because I was just trying to get my SUV calibrated.

very weird indeed.  actually...shouldn't be possible.  And I can't come up with any reason why it would happen unless you're talking about the SUV measuring differently.  The wave files produced from USB and JB3 should be the same.  The SUV levels will be affected by the monitor function on the UA-5 because the SUV is driven from the analog output and gets messed up when the monitor button is on.  You actually get a double signal, slightly delayed.

I hooked up my laptop and recorded a test tone with Soundforge 5. I was trying to get the levels set with SF5 since that is what I use to edit wav files anyway. Without touching any settings on the UA5, I unplugged the laptop and plugged in the JB3, recorded the test tone, transferred the file to the laptop and opened the file in SF5 to make sure the levels were set. To my surprise they were about 3 dB louder in both channels. If I get time today, I will repeat this with simultaneous recording to both laptop and JB3. I agree that it shouldn't be possible, so maybe I'm remembering this wrong, but it stuck with me because I thought it was weird at the time.

[dklein]

Is everything set to 16/44.1 and is the adv switch on the back of the UA-5 off?

[bluegrass_brad]

I actually found a converter very similar to the Ratshack one except it is only coax > optical.  Found it on ebay.  It was the same size and price as the Ratshack box.  The best thing about this one is it runs on 6v.  I'm hoping that it passes bitperfect testing, because I run an SBM-1 (coax mod) and it would be sweet to be able to just run it off the battery im powering the SBM-1 with.
here is a link to one on there right now....

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=14968&item=5721893974&rd=1

[ChrisV]

I had enough confidence in it so I used it for the Jack Johnson, G Love, Frankenreiter show at the Gorge last night.   I was actually barrowing another person's rig who had a SBM-1 but I wanted to use my JB3 rather than the DAT with it so I ran the Ratshack box off my 9.6 V battery I normally use for my UA-5(exact same plug even...just had to switch polarity of course).

[caymanreview]

I actually found a converter very similar to the Ratshack one except it is only coax > optical.  Found it on ebay.  It was the same size and price as the Ratshack box.  The best thing about this one is it runs on 6v.  I'm hoping that it passes bitperfect testing, because I run an SBM-1 (coax mod) and it would be sweet to be able to just run it off the battery im powering the SBM-1 with.
here is a link to one on there right now....

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=14968&item=5721893974&rd=1

i had one of those for awhile, i didnt notice any noticeable glitches with it. but i never tested its bit-perfectness

one member here said he had tested it, and it passed, but as always YMMV

[Cooker]

i ran the ratshack convertor friday night without incident. i was worried that the 9V duracell wouldn't last a whole show but it certainly did.  i ran mics > V3 > split coax >  Convertor > JB3 and 
                                                                  >   Luvean's M1

i haven't done any bit accuracy tests yet but the global file analysis tool in wavelab didn't turn up any errors.

i don't plan on using this convertor much but it sure was nice to have when Hatgis' V3 was just sitting in his bag, not being used at all....

felt like one of those kids with a $5,000 stereo in a 91 cavalier, running Oktavas into it

next step is wiring it to my 9.6v's

[Brian Skalinder]

felt like one of those kids with a $5,000 stereo in a 91 cavalier, running Oktavas into it

MC012s?  How'd it turn out?  I bet the MC012s sound awfully good in front of the V3.

[nic]

felt like one of those kids with a $5,000 stereo in a 91 cavalier, running Oktavas into it

MC012s?  How'd it turn out?  I bet the MC012s sound awfully good in front of the V3.

unfortunately, it was in probably the worst sounding room imagineable(McDonough Gym @ Georgetown U) and we were far from the "sweet spot"...actuallyl, there was no "sweet spot"
we were going to move the rig at setbreak, but there was no setbreak
recording came out better than it sounded there, so thats a plus.

in a better room, the Octavas>V3 would have sounded pretty sweet

[F.O.Bean]

any word on the bit-perfect tests