AliExpress SPDIF to AES converter

[tw99]

Amir did a review of a AliExpress USB to AES converter, which didn't perform well (although the test methodology was also questioned). This led me to have a look inside my AliExpress Coax SPDIF to AES device which seems to be from a similar heritage. Sadly they've removed the labelling on the two ICs, as had been done on the one Amir tested.

On the left hand side we have the coax input and a MicroUSB power input, AES out on the right.

I had a search for SPDIF receiver ICs, and couldn't find one that was 14 pins. Can anyone have an educated guess as to how this works ?

 

[Bamboszek]

SOIC-14 chip is probably just simple hex inverter or other generic logic chip used as logic level shifter.
SPDIF receiver is not needed, as apart from voltage levels and line impedance there are only slight differences between SPDIF and AES/EBU standards.

 

[voodooless]

The SOIC-8 is probably a simple line driver (opamp) driving the transformer.

 

[geoffrey5239]

The SOIC-8 is probably a simple line driver (opamp) driving the transformer.

In my Toslink to AES version the 8 pin chip is labelled as 09AD DS892. Mine has problems with the Toslink output from an LG TV which seems to be a known problem with LG TVs.

 

[Kal Rubinson]

my AliExpress Coax SPDIF to AES device

My AliExpress AES to Coax S/PDIF convertor device arrived DOA. I had no problem with a Canare or a Funk or a Weiss or a dumb adapter using pins 1+2. FWIW.

 

[phofman]

In my Toslink to AES version the 8 pin chip is labelled as 09AD DS892.

Differential Line Driver https://www.ti.com/lit/ds/symlink/ds8921.pdf ?

 

[solderdude]

Looks like what is used in the OP picture and drives the pulse trafo.

The circuit around the 14 pin dip is (very likely) the circuit below that drives the line driver (kind of reverse engineered it up to the line driver.
There is also a snubber across the pulse trafo input.

 

[tw99]

My AliExpress AES to Coax S/PDIF convertor device arrived DOA. I had no problem with a Canare or a Funk or a Weiss or a dumb adapter using pins 1+2. FWIW.

It's always a bit of a dice throw with AliExpress isn't it...

In my case I need the active adapter because my D&Ds don't seem to work reliably with the required passive cable (2.5M) from the SPDIF output from my MiniDSP SHD daisy chained through both speakers (+7M!). I'm right on the limit of what D&D say they tested, but it just doesn't work passively here.

 

[multichannel_guy]

My AliExpress AES to Coax S/PDIF convertor device arrived DOA. I had no problem with a Canare or a Funk or a Weiss or a dumb adapter using pins 1+2. FWIW.

What Canare model did you use to conver digital coax to aes/ebu? Or what other cheap item worked?

 

[masterhw]

What Canare model did you use to conver digital coax to aes/ebu? Or what other cheap item worked?

this is the Canare model typically used for AES to S/PDIF coax, but I’m not sure it works the other way around https://www.bhphotovideo.com/c/product/406162-REG/Canare_BCJ_XJ_TRB_BCJ_XJ_TRB_110_Ohm_to.html

 

[multichannel_guy]

this is the Canare model typically used for AES to S/PDIF coax, but I’m not sure it works the other way around https://www.bhphotovideo.com/c/product/406162-REG/Canare_BCJ_XJ_TRB_BCJ_XJ_TRB_110_Ohm_to.html

per this listing and reviews on the same site, it looks like it might work the other way around?

https://www.bhphotovideo.com/c/product/367655-REG/Canare_BCJXPTRB_BCJ_XP_TRB_75_Ohm_to.html/reviews

(title says -TRC, model # on the picture says -TRB , facepalm)

 

[voodooless]

If it’s transformer based, it usually works both ways. Except that XLR gender may be wrong. There probably exist a sister model for this.

 

[Kal Rubinson]

What Canare model did you use to conver digital coax to aes/ebu? Or what other cheap item worked?

I never needed to convert digital coax to aes/ebu. I only used them to convert aes/ebu to coax.

 

[multichannel_guy]

I never needed to convert digital coax to aes/ebu. I only used them to convert aes/ebu to coax.

ok, thanks anyways

 

[nagster]

I did a quick test on the CANARE BCJ-XP-TRC.
These are just the results from my own room. Results may not be the same in yours.

I used the CANARE to convert the AP's BNC digital output to XLR. The BNC cable was approximately 1.8m long.
I output a 997Hz sine wave with a sample rate of 192kHz from the AP and connected it to the AP's AES input, the TOPPING D90SE's AES input, and the GENELEC 8260A's AES input.
All three devices locked to the input signal. Sound was also produced. (For the AP, the monitor output was output from the PC speakers.)
I listened to two music tracks (44.1 kHz) with the D90SE (AES in) + 8260A (Analog in) and the 8260A (AES in).
There were no problems.

This link is a test of BCJ-XJ-TRB.

Topping DM7 8-Channel DAC Review

Thank you very much I knew it's just a DAC, not having DSP filtering features like the MiniDsp Flex. Precisely for this reason My question was whether the DM7 associated with a PC and a software like Equalizer APO could produce a stereo sound with two subwoofers. In this case, two channels for...

www.audiosciencereview.com

edit: After I posted this, for some reason the order of the images got messed up... I'm sorry if it's hard to see.

 

[four_strings_good]

Benchmark offers two Canare transformers, one for S/PDIF to AES conversion, and one for AES to S/PDIF. I have the former and it works perfectly, allowing me to connect a source with a coaxial S/PDIF output to the AES input on my Benchmark DAC2 DX. Link:

https://benchmarkmedia.com/search?q=canare