Optical vs. coaxial DAC connection

[NRG]

Leo, what / where did you get the pulse tx's?

I'm experimenting in that area at the moment with SB and Beresford DAC. Some mods already done to the Beresford IE Linear PSU (ALW SR to come), o/p cap replacement (before and after opamp), opamp replacement.

Found this improved performance and also that TOSLINK sounds just a bit better overall.

The 12v supply is split internally so next stage is to create new isolated 5v rails for DAC and 12v rail for the opamp.

[Rick O]

I believe the reason why I've always found that coaxial sounds better than optical is to do with the quality of cable. Although light is not affected by outside interference (such as EM), it is far more affected by the quality of and defects in the cable.

Optical has an advantage though: it is higher bandwidth than coaxial.

[leo]

I got the Pulse transformers from Digikey, they are 1:1 Newava S22083.
They need to be loaded properly though to get the best out of them.

Its quite a long winded job getting co-axial right, often the reason why people find toslink better

[Marco]

And also because the cables are generally less expensive.

Like you say, getting coaxial right is a bit of a ball-ache, so that's why good digital coaxial cables are expensive.

Marco.

[NRG]

Thanks Leo, maybe I'll drop you an email about how to implement these transformers with the correct loading.

Marco, I can't resist , what is your definition of a good digital co-axial cable?

[Marco]

One that sounds good!

Read as: does as little to mess up the signal as possible, such as the one below which I use:

http://transparentcable.com/products...tal_cable.html

In my experience, good sounding digital coaxial cables, such as I have described above, start around the £200 mark. Below this level they are sonically compromised.

Marco.

[NRG]

In my experience, good sounding digital coaxial cables, such as I have described above, start around the £200 mark. Below this level they are sonically compromised.

Marco.

Why do you think that is?

[Marco]

LOL. Because it's what my ears tell me!

I've owned (and auditioned) many digital cables over the years

Marco.

[Sand Dancin Donkey Walker]

Hi All
Just to add my digital thoughts to this thread. I am in the fortunate position to have the option of using RCA/Balanced and AT&T Optical between my Tx and DAC and been able to switch between them. I find the one I mostly use and come back to each time is the AT&T optical, the Balanced would be next then the RCA digital. There is no night and day differences but certainly changes between them. I just find AT&T is the one I come back to every time. Though this is obviously only within the context of my system.
Other trials with friends gear have shown usually if the option for balanced connection is available then that is more often the prefered option. Though I have not really had much success with standard optical cables. But I suppose it shows the each of us has different prefferences and needs.

Andy - SDDW

[Mike]

In my experience, good sounding digital coaxial cables, such as I have described above, start around the £200 mark. Below this level they are sonically compromised.

Marco.

Oh god no!.... here we go again!

Would you like me to make one for you?