Hello Folks,
from what I read it seems as if it may be a good alternative to use Toslink instead of SPDIF koaxial.
Like electric connectors coming in different qualities, I started to wonder about different qualities of optical/Toslink transmitters and receivers...
Thinking/Believing that cost gets optimised/minimised in our technical gear:
Which optical transmitters / receivers may be "better" than what is build inalready??
Which criteria and parameters do I need to look at to compare?
What is the impact of cheap vs. more costly?
I hope my intent becomes clear: I would like to understand these devices better to be able to choose good ones for my projects.
[Please let's leave Optical Cables discussions "off topic" in this thread, agreeing we have optimal ones at hand]
Thanks and Regards,
Winfried
from what I read it seems as if it may be a good alternative to use Toslink instead of SPDIF koaxial.
Like electric connectors coming in different qualities, I started to wonder about different qualities of optical/Toslink transmitters and receivers...
Thinking/Believing that cost gets optimised/minimised in our technical gear:
Which optical transmitters / receivers may be "better" than what is build inalready??
Which criteria and parameters do I need to look at to compare?
What is the impact of cheap vs. more costly?
I hope my intent becomes clear: I would like to understand these devices better to be able to choose good ones for my projects.
[Please let's leave Optical Cables discussions "off topic" in this thread, agreeing we have optimal ones at hand]
Thanks and Regards,
Winfried
TOSLINK has great isolation properties, so its good from that perspective. OTOH, TOSLINK tends to be more jittery that SPDIF, and SPDIF is more jittery than Asynchronous USB. There are solutions to remove TOSLINK (which is basically optical SPDIF) and or SPDIF jitter, if you care to. ASRC and FIFO buffering are the main ways.
IOW, the isolation of TOSLINK is not without its costs, at least for people who believe that jitter can be a problem. Also, if using SPDIF or Asynchronous USB then you may need to deal with isolation problems.
Bottom line is whatever transport medium you decide to use, none are super simple to fully optimize. That said, for most people Asynchronous USB is probably the most direct path to good sound if it is well implemented.
IOW, the isolation of TOSLINK is not without its costs, at least for people who believe that jitter can be a problem. Also, if using SPDIF or Asynchronous USB then you may need to deal with isolation problems.
Bottom line is whatever transport medium you decide to use, none are super simple to fully optimize. That said, for most people Asynchronous USB is probably the most direct path to good sound if it is well implemented.
Hello Mark,
thank you for your answer! I am aware of the issues you have raised, but USB is no option in my case because the DSP puts out BNC coax SPDIF or Toslink which needs to drive a connection of about 2 - 4 meters to the DAC located at/in the speaker and accepts BNC coax or Toslink as well.
My question was raised because I suspect that optical transmitters and receivers may come in various quality classes and wanted to find out which may be technically better than others, i.e. potentially better than those built into my equipment now.
At the end of the day I have both options of optical or coax connection and could therefore compare.
Kind Regards,
Winfried
thank you for your answer! I am aware of the issues you have raised, but USB is no option in my case because the DSP puts out BNC coax SPDIF or Toslink which needs to drive a connection of about 2 - 4 meters to the DAC located at/in the speaker and accepts BNC coax or Toslink as well.
My question was raised because I suspect that optical transmitters and receivers may come in various quality classes and wanted to find out which may be technically better than others, i.e. potentially better than those built into my equipment now.
At the end of the day I have both options of optical or coax connection and could therefore compare.
Kind Regards,
Winfried
Thoshiba
RX: TORX147L, TORX179L,
TX: TOTX147, TOTX179
are good ones I have had success with. I suspect they are out of production... so eBay may be fakes... but all I purchased up until end 2021 has been working OK for me with 5m toslink cables. I even made a data transfer over 5m to check BER - no errors over the 15-20 min transfer...
//
RX: TORX147L, TORX179L,
TX: TOTX147, TOTX179
are good ones I have had success with. I suspect they are out of production... so eBay may be fakes... but all I purchased up until end 2021 has been working OK for me with 5m toslink cables. I even made a data transfer over 5m to check BER - no errors over the 15-20 min transfer...
//
Well,
I've found Toshiba TOTX1350 and TORX1350A which are ~13€ devices each @ Mouser. They can transmit 0.2 - 50m distance with 1.5mA LED current (probably depending on fibre connected). Well, I guess I'll first make the system work with BNC coax and get back to Toslink tuning a bit later.
Thanks again!
Winfried
I've found Toshiba TOTX1350 and TORX1350A which are ~13€ devices each @ Mouser. They can transmit 0.2 - 50m distance with 1.5mA LED current (probably depending on fibre connected). Well, I guess I'll first make the system work with BNC coax and get back to Toslink tuning a bit later.
Thanks again!
Winfried
I use DLR2180/DLT111A Modules . These are low cost Chinese parts but offer satisfactory performance. On a no-name 3-meter (longest I have) toslink fiber they work with no issues at up to 24bit/192 KHz.
In my Whazon project I use 4 DLR2180 modules for RX and 1 DLT111A for TX. I've built multiple Whazon boards and the performance has been consistent.
The model numbers above are of the housing style. The vendor offers many other housing styles as well, supposedly with same electro-optical devices inside.
However for even higher bit rate or long distance/robust transmission, coaxial rules. Many use toslink for absence of ground loop between connected equipment. In coaxial interconnet, the ground loop can be easily defeated with a transformer.
In my Whazon project I use 4 DLR2180 modules for RX and 1 DLT111A for TX. I've built multiple Whazon boards and the performance has been consistent.
The model numbers above are of the housing style. The vendor offers many other housing styles as well, supposedly with same electro-optical devices inside.
However for even higher bit rate or long distance/robust transmission, coaxial rules. Many use toslink for absence of ground loop between connected equipment. In coaxial interconnet, the ground loop can be easily defeated with a transformer.