spdif hiss joe meek twinq

[glideman]

i have recently purchased a joe meek twinq which i think sounds pretty good but when i connect the spdif to my 003 i get a hiss. i have the twinq slaved via bnc to the digi but still hiss. ive tried slaveing the 003 to the twinq via spdif but its still there. im wondering if anyone else has noticed this with their twinq. also would a seperate master clock help eliminate hiss

[stoneinapond]

Originally Posted by glideman

... also would a seperate master clock help eliminate hiss

No. Wordclock has nothing to do with hiss. Check to see if you haven't got some input or output fully cranked. Also look at gain staging in general.

http://cara.gsu.edu/courses/MI_3110/...ging/gain1.htm

[glideman]

thats not it. when the gain and trim on the joe meek are turned all the way down theres a hiss from the spdif. the noise floor is about -85 db. when its plugged into the analog line inputs on the 003 with gain and trim all the way down the noise floor is -89.

[Premo]

Bad SPDIF cable?
I've never used that hardware so I can't say what the noise floor should be, but I'd try swapping cables just to be sure.

What if you do a loopback test with that SPDIF cable and record out spdif 003 and back into the 003 spdif IN port with that same cable, using Signal generater inserted on the first channel passing out to the second receiving channel. Is that signal noisy or dirty? That would verify it's not the SPDIF ports or cable you're using.

[glideman]

thats a good idea. ill try it but as of now im convinced that the digital output from the joe meek is just low quality. i tried 2 different spdif cables. one that is for a tv and another that i went and bought that was "double shielded." with both i still got the hiss. i have a presonus firestudio that i have been using as a spdif preamp and that thing is dead quiet with the same bnc and spdif cables. i thought i was upgradeing when i got the joe meek but i guess not. the meek still sounds really good through analog but my whole plan was to use it with spdif and get 18 channels. now i have to keep using the firestudio to get 18 channels. bummer

[stoneinapond]

Originally Posted by glideman

thats a good idea. ill try it but as of now im convinced that the digital output from the joe meek is just low quality. i tried 2 different spdif cables. one that is for a tv and another that i went and bought that was "double shielded." with both i still got the hiss. i have a presonus firestudio that i have been using as a spdif preamp and that thing is dead quiet with the same bnc and spdif cables. i thought i was upgradeing when i got the joe meek but i guess not. the meek still sounds really good through analog but my whole plan was to use it with spdif and get 18 channels. now i have to keep using the firestudio to get 18 channels. bummer

I'm still confused why you are getting hiss via the S/PDIF connection. I do notice that you appear to be using the wrong kind of cable. You need to get a 75 ohm cable that is specifically designred to carry digital signals. While regular RCA cables can work, they are not recommended.

I also note that the JM unit has a relatively high noise spec. Unless there is something really amiss with the converter section, I would think that the noise level would be the same, whether analog or digital.

[glideman]

yes the "double shielded" cable i got was specifically a spdif cable but both cables measured at around 75 ohm. Really, what I'm looking for with this thread is for someone who has tried the joe meek twinq to tell me whether or not theirs had extra noise from the digital out so i can decide if my unit has a bad digital card and whether i should send it in or not.

[rainsong]

i don't have any experience with that unit, but i'm pretty sure if i had that experience i'd be taking it back where i purchased it from to get another one. sounds faulty to me.

[glideman]

new ones on the way. hopefully will be better

[glideman]

i just got the new one and it still has the hiss. bummer ill have to keep this presonus thing around just to use as a spdif pre.