Isolator for digital audio is needed in cases where coaxial S/PDIF digital audio link forms a ground loop in your audio system. Typically in coaxial S/PDIF connections the coaxial cable shield is connected to equipment cases. This arrangement easily creates ground loops which can cause noise problems in various places in audio system. A suitable transformer can be used to isolate the coaxial S/PDIF signal and avoid ground loop problems (other option is to use optical connection instead of coax). Here is the circuit of the S/PDIF signal isolator I have used:
ELFA catalogue product 56-550-55 “PE65612 Trafo dig.siirt.” is a tranformer suitable for isolating S/PDIF digital audio signal. The manufacturer for this product is Pulse Engineering and their product code is PE-65612.
Ratio: 1:1
Bandwidth: 100 kHz-55 MHz ±3 dB
Here is a picture of the S/PDIF signal isoltor I built (box open):
More information on S/PDIF and related circuits can be found on my SPDIF document.
24 Comments
Adolfo says:
Hi, since I found it very interesting and since I have on hand some of these transformers, can I have a more clear picture of the box, or at least an easy schematics of how to connect the 4 pins of the trafo, please? thanks in advance! Adolfo
tomi says:
Thank you for your feedback.
I add more information to the blog to clear out the details.
tomi says:
I just added a new circuit diagram drawing that shows the exact connection of the transformer I used in my ciruit I built. The RCA connector on the left connects to transformer primary and the RCA connector on the right the secondary. It ideal direction for the signal would be from left to right throught this isolator (although the circuit works also well on other direction).
tomi says:
There is an RSS feed button on the right…
Computer Upgrades chicago says:
You certainly outdid yourself this article. I am very impresses
Jon Brink says:
Great post. Not sure I agree with everything. But it was very well thought out.
Jon Brink says:
I wish there were more pictures (I admit it… I’m a photo junkie).
Galfryd says:
hi, your website is really unquie. I really do many thanks for give good results
Monroe Peitz says:
Useful information. Fortunate me I found your web site by accident, and I’m stunned why this twist of fate did not happened earlier! I bookmarked it.
customer service resume examples says:
okay so i downloaded firefox. i’ve been using firefox for a while, and all a sudden when i x’ed out my firefox and opened it again it wont go to websites, it wont even say page not displayed. it will just be blank. so i unstalled it and re stalled it and it worked when it was launched from the reinstal but when i x’ed it out again and opened it it showed blank. does anyone know how i can fix this????.
Inspirational Quotes says:
I really like when you address this type of meaninglessness internal your posts. Perhaps could you uphold this?
Friendship Quotes says:
Great post at Digital audio isolation Tomi Engdahl’s ePanorama blog. I was checking constantly this blog and I am impressed! Extremely useful information particularly the last part
I care for such info a lot. I was looking for this particular information for a long time. Thank you and best of luck.
brindes says:
I have study not one particular write-up in your blog. You’re a large lad
droid razr hd says:
Wow, amazing blog layout! How long have you been blogging for? you make blogging look easy. The overall look of your website is magnificent, let alone the content!. Thanks For Your article about Digital audio isolation Tomi Engdahl’s ePanorama blog .
read here says:
I witnessed this post awesome article
Paleo says:
Unique perspective. Thank you for posting this. I’ll definitely return to your site to find out more and recommend my neighbors about this.
Paleo says:
I agree. Thank you for posting that. I will definitely return to this site to read more and tell my coworkers about this site.
cindy says:
Just wanted to drop by and say thanks for this post!
Tomi Engdahl says:
Use plastic optical fiber for isolation
http://www.edn.com/electronics-blogs/anablog/4443041/Use-plastic-optical-fiber-for-isolation?_mc=NL_EDN_EDT_EDN_analog_20161201&cid=NL_EDN_EDT_EDN_analog_20161201&elqTrackId=2d95b60583b443149364cb9c6d5da32f&elq=7517261bace8488e9b40d5df4abd1fc7&elqaid=34983&elqat=1&elqCampaignId=30538
Don’t overlook using fiber optics to achieve isolation. The Navy learned to love optical fibers since they are insensitive to EMP pulses from nuclear weapons. Glass fibers are expensive, and you can expect to pay 25 to 100 dollars for the transmitters and receivers. Then again, glass fibers work to GHz frequencies. A much more cost-effective solution is plastic optical fiber (POF). Here data rates are limited to 10 or 100 MHz, but the costs are closer to 5 dollars for transceivers.
Tomi Engdahl says:
Do It Yourself Musician #4 – Fix USB Audio Noise with HifimeDIY USB Isolator
https://www.youtube.com/watch?v=GbNyINuo-Uw
use the HifimeDIY USB Isolator to solve a USB ground loop problem in my home recording setup. If you have a high pitched whining noise in your USB audio system, take a look at this video.
https://www.amazon.com/gp/product/B00F4SCCR2/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00F4SCCR2&linkCode=as2&tag=internati0501-20&linkId=QPGZM62EU45K5D2K
Tomi Engdahl says:
Interfacing AES3 and S/PDIF
https://www.ranecommercial.com/legacy/note149.html
tomi says:
Feel free to quote as long as you don’t quote all the text and remeber to mention the source you took the text. And also provide link back to my blog.
I am not Twitter user. Should I use Twitter?
tomi says:
Alarms are a valid topic in ePanorama.net. There is even a alarm technology link page at http://www.epanorama.net/links/alarm.html
But why are you posting this alarm comment to this posting not related to alarms?
tomi says:
WordPress is a good platform. I use it.
The problem with WordPress is that because of it’s popularity, many people try to hack to it.
To keep your own site secure, you need to keep you updated what problems are found and
be prepared to update your WordPress installation when new serious issues are found
(before bad people hit your site). Be prepared to be able to do that update often, or
get somebody that can do this for you at short notice.
Security problems are found every now and then on practically all popular web systems…
Whatever platform you choose, be prepared that you need it update every now and them to keep it secure.