Topic: iRiver stuff - optical jack parts and schematics...

[tubehead]

hey y'all, got my iriver yesterday and started screwing with it, but no rockbox yet..i do have a few burning questions tho, does anybody know the part numbers of the optical/audio combo jacks on there?? i'm planning on converting them to coax so it would be nice to see the datasheet if i could find the part number.  i've heard there are schematics out there, is there a location where they're posted?? i'm also looking for the codec part # too

i did a few unconnected (analog) input wav records, the noise floor looks pretty horrid, a few constant tones (biggest at 12khz) and lots of temporal noise...when i get around to it i'll post some spectrograms...

[whatboutbob]

Codec is the same as the JB3:  UDA1380TT

There's a fair bit of detail here:

http://www.rockbox.org/twiki/bin/view/Main/IriverNavigation

[whatboutbob]

oh...and schematics...: http://www.rockbox.org/twiki/bin/view/Main/HardwareSchematics#Schematics_of_the_iriver_iHP_120

[Sanjay]

let me know how replacing optical with coax works, I would be thrilled if this could be done.

[tubehead]

thankx for the links on the schematics, the opto/line jack i still can't find though...the other thing i was thinking is how are 6 rca jacks going to fit on that thing?! i would love to have analog rca breakouts too, i am sort of thinking about making an extension and putting like a vx pocket connector or 9 pin DSUB and making a breakout cable for it...have to figure it out...i still need to do the noise floor thing...all good things in all good time...l8r...Nick

[tubehead]

so i did the first tests on the iriver this weekend, with ground terminated inputs (short both L,R to the shield) the noise floor is at -89dB (referred to full scale) and the waveform shows 2-3 LSBs of wiggle.  it was about the same with the termination removed.  i also changed the 'gain' setting (in rockbox) while it was recording for another test (unterminated inputs) and the noise floor never changed and there were no blips or any other temporal noises...so the science checks out, looks pretty good from an engineering standpoint, there are other threads here that have subjective tests...i'm planning on doing some 'sound quality'/sonic character tests myself but havent' gotten to it yet...anyway, you know what they say about opinions

[aberg]

If you can mod these to use a coax digi-in i'd be VERY interested.

[tubehead]

i'm sure it's possible, what you have to do to make it work is another thing, i haven't popped mine open because i have to get the right size mini-torx bit, i thought it was held together with allen screws but it's torx #5 or some BS...there are good photos of the innards on the rockbox site that show the opto reciever and transmitter parts, but i still haven't found the actual part number of those, there are some numbers printed on them but i think it's an abbreviated part# or a date code or something....

having the actual part number etc. isn't really necessary, the pad on the board for the optical signal should be easy enough to find, all you have to do is jack the coax signal onto that...for the input (only) i was thinking you might be able to replace it with a standard minijack and connect the tip of the analog signal with the tip of the digital signal - the codec ignores the one that isn't selected, so the analog input going to the digital input probably wont' affect things too much, but the digital input going to the analog input may be weird, depending on wether or not you feed it 5v s/pdif or 0.75v s/pdif. possible tho, i'd have to rig it up and see if there were any negative interactions.  i don't think it's the same with the output, if the digi out is still on and you feed that to the analog output it's bad news....so in only is feasible.  the problem is the i/o though, if you break all of the i/o out that goes into the 2 1/8" jacks you'd need 6 RCAs...2x input, 2x output, digi in and out...clever soultion by the iriver folks, i just hate optical digital signal transmission....