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Gear / Technical Help => Recording Gear => Topic started by: divamum on November 29, 2006, 08:37:28 AM

Title: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: divamum on November 29, 2006, 08:37:28 AM
Hi y'all -

I've been using an older Rockbox build (from about March, I think) but I now need the optical feature so... Can anybody recommend one which has been stable for them? (link to a d/l app'd if you have one).  The older one I've been using has been fine, but I DID have problems with a couple of builds when I first set up the firmware, hence why I haven't been too keen to change it, and why  I'm asking here for one which somebody has used successfully for a while rather than just going to Rockbox and linking off there.

Tia!
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: divamum on December 01, 2006, 08:35:43 AM
Bumpitity bump - anybody?   

Which builds are folks using at the moment and when did the optical become officially adopted (assuming it has been made "official")? 

Ok, off to go search (again - I promise I looked before I posted, but itwould'nt be the first time I've missed the blinding obvious, so apologies if I'm doubling up on something I missed!)
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: aberg on December 01, 2006, 09:28:44 AM
I'm using a build from November 14th without any issues at all.
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: petur on December 01, 2006, 10:46:38 AM
You're always welcome to give the latest build a good test. I will do this tomorrow anyway as I have a gig to tape at night :)
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: knoxmallette on December 01, 2006, 11:05:42 AM
I'm using the 12 September 2006 build and have had no issues.
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: divamum on December 01, 2006, 11:10:42 AM
Thanks guys - just the kind of info I need.  Am I right in thinking that optical-in is included in those and not a patch?

Where are the older releases available? They only seem to go back about a month on the Rockbox site as far as i can tell...  Tx!

Petur, my problem is that I can't really risk taking an "unproven" build on a test run for these gigs - I'm already running optical for the first time now that i've got the Core 2496 and so am trying to minimise problems elsewhere in the chain!  But thatnks... maybe I"ll play around with that one when I have time for a few more test runs...
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: aberg on December 01, 2006, 11:11:30 AM
Nov 14th has optical built into that build.. everything runs great. I'd suggest it.
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: divamum on December 01, 2006, 11:17:01 AM
Thanks Berg - I'll give it a try.  Any tips for a newbie to optical?  Thanks!
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: 612 on December 01, 2006, 12:19:45 PM
Thanks Berg - I'll give it a try.  Any tips for a newbie to optical?  Thanks!

I think I'm still using one from the end of July without problems and I record optical. Should probably update though.

Not sure what tips you are looking for re: optical but I run this cable out of my UA-5 into my h120, just make sure the Source is set to Digital on the h120. I'm not familiar with the Core2496.

http://www.mcminone.com/product.asp?catalog%5Fname=MCMProducts&product%5Fid=24%2D6475
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: divamum on December 01, 2006, 12:33:52 PM
Tx.  I seem to recall reading that there was a glitch where you had to boot up then plug in or somesuch - not sure if that's still a problem or not. Also, presumably I just set it to 16/44.1 on the Core and let the iRiver "read" that, or do I have any other adjustments to make on the iRiver itself (since I hvaen't got the firmware loaded yet, I'm not sure what's in there!).  I guess I'm wondering about any tripwires so I can get my settings straight and out of the way before screwing it up in some new and unusual way anyway ;)

DM (the Girl Who Has Forgotten that "Standy By" is NOT the same as "Record" too many times, regardless of how pretty the level meters look..... )   :-[
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: divamum on December 02, 2006, 02:26:03 PM
Ok, got 14th November loaded, all seems well.

Question:  if I'm running optical and setting levels on the external pre, what level should the iRiver be set at - 0?  Or -X? 

Thanks!!
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: Ryan Sims on December 03, 2006, 12:28:23 AM
That level on the iRiver, best I can ascertain, is only the volume to the headphone and line-out jacks; it has no impact on the recording levels.
Title: Re: Recommended stable iRiver 120 Rockbox build w/optical?
Post by: cgrooves on December 03, 2006, 01:06:22 AM
The h120 is limited at 16 bit, so even if you feed it a 24 bit signal it will just truncate it down 8 bits.   It will record at whatever sample rate you send to it automatically.  When running the h120 digital in, the internal pre (gain stage) is bypassed, so there is no 'level' setting to worry about on the unit itself.  Just watch the levels on the screen and do your adjustments with the external pre.
Title: Iriver optical-in questions
Post by: divamum on December 03, 2006, 09:12:01 AM
Thanks - since that level meter was there with the option to adjust it I couldnt' figure out quite what was waht since it was obviously responding to the adjustments on the pre.

Next question (I posted this in ask the tapers, but it bears repeating here in an iRiver-specific thread too):  Okey dokes...

I ran a test last night - mics and pre are talking, there's a signal, batteries fresh etc.  However,   it came out like the freaking chipmunks on steroids - clearly running fast (it's pretty funny, actually) - and when I u'l'd it to the puter it was telling me it was 64k instead of 44.1 that was set on the Mic2496.  How did the sample rate get screwed up?    The iRiver told me it was "same as source" so I can't figure out any way of setting it specifically.   Also, I can't get it to repeat the fault - my concern, of course, is that if I don't know what caused it I don't know how to avoid it so any pointers on how to ensure this doesn't happen again warmly welcomed!  Thanks. :)

 
Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: cgrooves on December 03, 2006, 12:49:45 PM
The 'level meter' adjustment you are talking about on the iRiver is just the headphone output (monitoring) level.

I think the wav header is messed up on the recording, causing it to play at a different sampling rate.  You'll have to search the threads to make sure that's the problem & find out how to repair it.

Good to hear that you can't repeat the error.  I've never had my h140 record anything but the same sampling rate that I sent it via the optical signal.  Did the recording screen say 64k instead of 44.1 when you were recording?

Good luck!
Title: Re: Iriver optical-in questions
Post by: Chuck on December 03, 2006, 01:23:57 PM
Perhaps you imported it into your editing program at the wrong sample rate? I have noticed this problem sometimes when working with CuBase.

Thanks - since that level meter was there with the option to adjust it I couldnt' figure out quite what was waht since it was obviously responding to the adjustments on the pre.

Next question (I posted this in ask the tapers, but it bears repeating here in an iRiver-specific thread too):  Okey dokes...

I ran a test last night - mics and pre are talking, there's a signal, batteries fresh etc.  However,   it came out like the freaking chipmunks on steroids - clearly running fast (it's pretty funny, actually) - and when I u'l'd it to the puter it was telling me it was 64k instead of 44.1 that was set on the Mic2496.  How did the sample rate get screwed up?    The iRiver told me it was "same as source" so I can't figure out any way of setting it specifically.   Also, I can't get it to repeat the fault - my concern, of course, is that if I don't know what caused it I don't know how to avoid it so any pointers on how to ensure this doesn't happen again warmly welcomed!  Thanks. :)

 
Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: divamum on December 03, 2006, 10:53:33 PM
Tx for the further replies.

As for the file, playback was funky on the unit itself (before uploading) so I guess it was something at the iRiver end.

Ran it twice today: once going optical-in via the CS2496 at a rehearsal tonight - mostly satisfied except for a $*()@& ventilation system hum in the 40-60k range (next stop: learning about noise filters, I guess).  Also, there were a couple of digital "pops" in one place - jsut the once (am I right in thinking that's just a digital error? Any way of avoiding, or just one of those things that happens?)

Was less happy when I ran  the CMC8s straight into it earlier this afternoon to stealth my daughter's choir concert - it seems that the newer firmware makes a big difference in many ways, and it's like running a whole new machine.  Biggest problem is that the mics REALLY picked up the hdd noise, much worse than it has EVER been. Not sure why - they were too close, but when this has happened before it's been a faint background whirring - annoying, but not actually deafening; this time it was like a Boeing revving up right next to the microphones.  Weird. 

As I say, there is a steep learning curve going on here.... more after Tuesday when I'll be running it again for the performance!
Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: whatboutbob on December 07, 2006, 04:21:33 PM
Was less happy when I ran  the CMC8s straight into it earlier this afternoon to stealth my daughter's choir concert - it seems that the newer firmware makes a big difference in many ways, and it's like running a whole new machine.  Biggest problem is that the mics REALLY picked up the hdd noise, much worse than it has EVER been. Not sure why - they were too close, but when this has happened before it's been a faint background whirring - annoying, but not actually deafening; this time it was like a Boeing revving up right next to the microphones.  Weird. 

Just for the record, divamum was accidentally recording using the internal mic.
Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: petur on December 11, 2006, 03:48:37 AM
Was less happy when I ran  the CMC8s straight into it earlier this afternoon to stealth my daughter's choir concert - it seems that the newer firmware makes a big difference in many ways, and it's like running a whole new machine.  Biggest problem is that the mics REALLY picked up the hdd noise, much worse than it has EVER been. Not sure why - they were too close, but when this has happened before it's been a faint background whirring - annoying, but not actually deafening; this time it was like a Boeing revving up right next to the microphones.  Weird. 

Just for the record, divamum was accidentally recording using the internal mic.

Just for the record, I've changed the text from 'Mic' to 'Internal Mic' :D

But as something still is fishy with current builds (re recording) I'd hold off a bit with updating to the latest build
Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: cgrooves on December 11, 2006, 11:30:26 AM
Just for the record, I've changed the text from 'Mic' to 'Internal Mic' :D

But as something still is fishy with current builds (re recording) I'd hold off a bit with updating to the latest build

+T
That should clear up a lot of confusion for people new to recording via iRiver.
Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: divamum on December 15, 2006, 11:46:21 AM
Thanks Petur.

Update on the sampling issue that prompted this thread:    I figured out how it happened, cuz I reproduced it (I caught it this time, at least).  So, in case somebody else ever needs to know:

It appears to reset (wrongly) sampling rates if the optical cable is unplugged/plugged while the iRiver is switched on in standby and/or if you try to press "record" before you have plugged in the cable (it seems that if the source is selected as digital, the unit won't start recording UNTIL the cable is seated in position).  The soluution is a simple reboot, then plug in BEFORE going to record.

I'm using it with a Core mic2496, btw.

Title: Re: Iriver optical sampling question (was "Recomended build for optical ...")
Post by: petur on December 18, 2006, 03:27:20 AM
Yes, samplerate is measured for real (*) the moment you start recording.
I can't remember exactly what happens if you're recording into a compressed format, it could be the encoder gets reconfigured (pre-rec data wiped).

(*) the value that is put in the header of the recorded file