Replacement for obsolete ADC

[LordBBQ]

I’ve been trying to repair a XTA DP448 rack mount digital audio processor which has terribly distorted/no input on ch1/2.
I’ve narrowed it down to a faulty ADC which is an AKM AK5394AVS 2ch 24bit 192kHz ADC which unfortunately is obsolete and I haven’t been able to find one from a reputable source.
I am wondering if there are any drop in replacements available (couldn’t find any myself) or sources that might have them still. Some sellers on eBay claim to have brand new stock but those are mostly comming from China which makes me suspicious of their authenticity. Being a pretty mission critical piece of equipment if I can’t get a known good chip I wouldn’t take the risk on a fake.

[MathWizard]

IDK much about ADC IC's, but if you have the datasheet, did you try looking on places like Digikey, and just filling in as many spec's as you can, just to narrow down some candidates that way ?

[Zenith]

Digikey have it listed as obsolete, but suggest AD1877JRZ as a substitute. They are $28 so check thoroughly before ordering.

I wouldn't trust any IC like that from China. I've heard too many stories of fakes.

[LordBBQ]

IDK much about ADC IC's, but if you have the datasheet, did you try looking on places like Digikey, and just filling in as many spec's as you can, just to narrow down some candidates that way ?

Thankfully I've got the datasheet - had a bit of a look and can't find anything in the same package & pin-out (there's a TI part in the same package but totally different pin-out). Would prefer to not have to make up an adapter PCB if I don't have to since that's going to get expensive.

Digikey have it listed as obsolete, but suggest AD1877JRZ as a substitute. They are $28 so check thoroughly before ordering.

I wouldn't trust any IC like that from China. I've heard too many stories of fakes.

Thanks, had a look at the datasheet and it seems to be a 16bit ADC so don't think it'll work unfortunately.

[1audio]

The AK5394A was he highest performance ADC for many years. It has been used in quite a few premium audio recording systems.  The process and the package were discontinued which caused AKM to discontinue the part.
PM me, I have the remains of the an EMU 1616M that I can harvest an AK5394 from for you. It has a dead FPGA but the ADC's are all fine.

[Audiorepair]

A couple of years or so ago I bought an AKM ADC (don't know if this exact one) from Ebay from what I thought would be the vendor most likely not to sell fakes.
There was no alternative.

After installing it, I found the isopropyl alcohol I used to clean up partially removed the lettering.
It did work, but was noticeably brighter than the other AKM's in the unit.

Lesson learnt.

[LordBBQ]

A couple of years or so ago I bought an AKM ADC (don't know if this exact one) from Ebay from what I thought would be the vendor most likely not to sell fakes.
There was no alternative.

After installing it, I found the isopropyl alcohol I used to clean up partially removed the lettering.
It did work, but was noticeably brighter than the other AKM's in the unit.

Lesson learnt.

Thanks, unfortunately what I figured.

[Audiorepair]

I've just had a look, and the IC I bought was AK4393VF.

This in a Turbosound Loudspeaker Management system.



Edit:  I think the Turbosound is actually a rebadged XTA similar to the one the OP has.

[Zenith]

Nikko Electronics sell them on ebay uk. They are £75 each plus delivery. I assume delivery to Oz would be quite expensive, if they are prepared to ship there. Nikko are a reputable parts distributor which has been trading for years, so they are likely to be genuine. I have dealt with them a couple of times. They also have a website.

https://nikkoe.com/

It seems like a lot of money. It might be possible to recover one from a non-working unit being sold for parts.

[Audiorepair]

1audio posted here earlier that the EMU 1616M uses these chips.

So buying one of these units from Ebay would be a way of getting hold of some known genuine used ones.



Edit:  Caveat - I just bought an EMU1616 cheap on Fleabay, without realising its not an EMU 1616M.
This 1616 version DOES NOT have AK5394 in it, you would need to get the 1616M version it would appear.

For reference, the 1616 version has:
AK4113VF       x 1
BB PCM1804   x 3
CS4392KZ      x 3

[1audio]

Correct- the 1616M (for Mastering) has 4 AK5394A ADC's. Otherwise its the same it seems. They use the same PCB even. I found them challenging to work on and not getting the pins connecting the boards lined up correctly will fry the FPGA. 
The 1212M is an internal card with 1 AK5394A that connects to the host card.
The AK5394A had been the highest performance ADC until quite recently. It was discontinued when the package was discontinued. And then the AKM foundry in Japan burned making for a big mess. AKM has recovered with new and different chips and a focus more on sensors.