Ethernet to Fiber media converters


(Sean) #143

Note - it is these two designers saying their DACs are relatively jitter immune… they are not talking about the Pro-Ject S2 DAC and other DACs… That post I shared of the Mojo is Rob Watts talking about his Mojo… not other people’s DACs…

Have you listened to Rob Watts and Ted Smith’s DACs and compared TOSlink sources? And different TOSlink sources and different TOSlink cables sound different to you, with their DACs specifically?

Respectfully, if you are not talking about their DACs specifically then I’m not sure I understand your point. Nobody is claiming that all DAC’s on the planet have no TOSlink jitter issues …


(Sean) #144

And for completeness, I already shared the Rob Watts Mojo post and comment above.

And here is Ted Smith regarding his DirectStream DAC with TOSlink input…


(Magnus) #145

Fair enough, I was talking about my experience on my DAC and not those. Judging by those graphs, its going to be hard to beat toslink (on those DACs) with another connection since it looks jitter free and is isolated.

It would be interesting to know from people who have used for example a Hugo 2 and tried different toslink cables, did different cables change the sound?


(Sean) #146

Understood. I just provided all that context in reply to your comment about the Mojo specifically… "I kind of doubt that. Attaching a Mojo to a Chromecast Audio (mini toslink) or to a transport like Allo DigiOne is not going to result in the same sound."

I wouldn’t doubt the designers of their own gear - not those two specifically anyway :wink:

If we are now talking about the S2 DAC, there are some measurements that show incoming digital coax jitter isn’t as good as it’s USB input, especially with 44.1kHz content:

https://www.computeraudiophile.com/forums/topic/34777-pro-ject-pre-box-s2-digital-mqa-hw-decoding-at-reasonable-cost/?do=findComment&comment=782569

I assume assume TOSlink’s jitter measurements would be either the same or worse (not better…).

The 192kHz jitter measurements aren’t too bad and I remember it sounding great when I had Roon up-sampling to 192kHz. It’s nice to have a DAC at this price that can support PCM192kHz and DoP64 over TOSlink too.

Jussi’s USB measurements are all very good, even with stock PSU, and slightly better/best with PCM768kHz and DSD512 per Jussi’s measurements.

It’s a superb DAC for sure. And when you power both DAC and USB source with battery, you fully eliminate potential for ground / leakage currents (through the DAC anyway) and it’s happy days indeed.


(Hans Bogaert) #147

I’ve heard that toslink is designed for 44.1 kHz, It can go higher but that has an impact onthe quality when going above 96 KHz.
I read ted smith his comment on toslink comment and that you can go up to 96 KHz but have to be carefull when going higher?. Ted Smith works for PSaudio and the ceo Paul McGowan answered a TOS related question a while ago on his YouTube channel stating that he is not a big fan of toslink and that copper sounds better with high res files. Is he wrong ?


(Magnus) #148

Measurements are nice, but don’t always tell the whole truth (especially measurements from the manufacturers). I still very much doubt that a Huge 2 connected with a no-name toslink to a Chromecast Audio will sound same as when it’s connected with a good toslink cable to for example an Auralic Aries G1.


(Sean) #149

Actually the standard is 96kHz. Finding a source & cable combination that passes higher than 96kHz is the challenge. And the DAC input needs to support it too obviously.

I haven’t seen that but the way I look at it is, it doesn’t matter if it’s the CEO or you or me - if it’s not the designer talking, it’s just a subjective opinion.

Ted is the designer and he is very clear that TOSlink is technically best (with his DAC - this is important as it seemed to cause confusion a few posts up) because it perfectly isolates current and EM/RFI - even though he uses USB mostly himself because he has a lot of DSD recordings (TOSlink can pass DoP64 but nothing higher).


(Hans Bogaert) #150

Sean, It was not my intention to rank authority’s by stating MCGowan is the CEO, his comments are based on his personal opinion and I find it a blessing when different opinions/ angles are shared.
The most efficient way for people like me to learn on these topics is to gather information from people with experience like yourself. Converting the different opinions that are shared into something practical is the hard part.
My FMC converter experiment is one that gave a boost to how my set sounds and important for me, I also understand the reason why.
I have many DSD files and also PCM at 192KHz I therefore have stayed away from TOS.
In essence FMC and TOS are 2 solutions how one can isolate electrical connections.


(Sean) #151

Hans, I agree, I enjoy hearig other people’s subjective opinions too. I was just answering your question about Paul… “Is he wrong ?”…,

His personal preference can not be wrong (just like mine and yours - our subjective preference is always right) but if he disagreeing with the designer on a technical level (I haven’t seen it by the way) then… this is the point I was making in answering your question.


(Magnus) #152

I will try and fix the linear power to the media converter myself (more fun). Here is a picture with the passive power regulator circled.

Unless I am mistaken, all you need is to cut the “vires” at the right part of the circle, and put your own power in there. Now, I assume it will need steady power so connecting batteries directly will probably not work, so I ordered one of these to do the job (3.3V version): https://www.ebay.co.uk/itm/253916560223

A fun and cheap little tweak, and if I break the media converter, its not like a new one is very expensive :slight_smile:


(Daniel Beyer) #153

I have used TOSlink and 24/192 files for years and never had a problem.


(Sean) #154

You are brave. Which model number FMC do you have again?


(Magnus) #155

TP-Link MC100CM, about 40$ here in Sweden
Btw, according to some guy on a Swedish forum, its not a switched voltage regulator in it, but a passive one.


(Sean) #156

Ok, different model to mine. There’s no other regulators , just one?


(Magnus) #157

Dunno, I am not good at electronics (got some help from others in this case). Will probably end up breaking it and buying a new one :slight_smile:

But at the very least it will bypass the first regulator, and make anything above 3.5V suitable for a power supply.


(Mr Fix It ) #158

Just remember that when you drop voltage you get heat…so the higher the voltage in to drop the more stress you put on the regulator


(Magnus) #159

Yes, think I will run it with 3 1.2 AA batteries, those should be over 4V charged and slowly go down to 3.6 and then its time to recharge. Of maybe use one 18650 3.6V batteriey.

Btw, if more volt produce heat, that would mean that for example 8 * 1.2 in series would not last as long as 3 * 1.2 in series.


(Mr Fix It ) #160

Well its also dependant on the current being drawn


(Sean) #161

This is why I got SOtM to mod mine (a few regulators replaced and caps).

They actually measured current drawn across the existing components and then selected appropriate component upgrades. They know this stuff inside out, having made networked streamers for a long while now.

But the actual optical to copper conversion section - they didn’t touch. Understandably.

I applaud your courage though @Magnus ! I didn’t have the patience to attempt what you are attempting.


(Magnus) #162

I am sure SOtM can do this much better than I can, I just like to “get my hands dirty” from time to time. I might still end up using SOtM, either because I can’t get it to work or just to compare.