Add Coax Out to M-Audio Transit?

[TerryC]

I'm looking for as much detail as possible describing how to add a coax out (or replace Toslink) to an M-Audio Transit. I would also be interested in any other succesful modifications ala Emperical Audio's mods.

 

[georgehifi]

If you instal a Tent Labs XO3 clock, not only will you get a vast improvement in sound quality, it also has a very good digital coax output built into the board, so you'll get the best of both worlds.

Cheers George

 

[georgehifi]

Forget what I said, I thought you misspelt transport, I just saw what a M-Audio Transit is, and it will never fit.

Cheers George

 

[JohanH]

Hello Terry,

I'm looking for the same info.
Did you find anything?

Thanks,
Johan

 

[paologatto]

Here http://www.epanorama.net/documents/audio/spdif.html there are some conversion schematics.

 

[Jocko Homo]

Those will work, but they all suffer from the same mistakes. There are better examples on this forum.

Jocko

 

[JohanH]

Like this?

Hello Jocko,

Do you mean a circuit like this from the NEC 602 thread?

http://www.diyaudio.com/forums/showthread.php?postid=594489#post594489

The other information I would need is to know where I can tap the TTL signal from the M-Audio Transit.

Thanks,
Johan

 

[Nisbeth]

Re: Like this?

The other information I would need is to know where I can tap the TTL signal from the M-Audio Transit.

On the input-pin of the optical transmitter 🙂


/U.

 

[Jocko Homo]

I never tried using any RS-422 TX parts. Seems odd to have an inverted output available, and not use it.........

Anyway, the drawback to using both the inverted and non-inverted ooutputs is that there may well be some prop delay in one of them. Unless they are perfectly aligned, don't use them. I have yet to see a F-F where they are, but I see people trying to use both together all the time.

I notice that the output Z of the 2 outputs is not identical, so that may be a clue.

Jocko

 

[adev]

I used a simple resistor divider on the input signal of the optical output which works like a charm (don't remember the exact values anymore but i think 300&75 ohms or so will be ok).

Actually, I removed the useless analog output part of the transit to route the 'coaxial' spdif through the 3.5mm jack 😀

 

[Jocko Homo]

It needs to be >75R. 100R || 300R is a lot closer. Figure the output z of the chip is around 30R........close enough for a guess.

Jocko

 

[JohanH]

Just found this

Hello all,

just found this with some nice pictures.

http://www4.head-fi.org/forums/showthread.php?t=131150

Cheers,
Johan