JCAT Femeto XE Card

[Stellabagpuss]

May be a dumb question, with most modern DAC having low jitter on USB input these days, is it a waste of money investing in a JCAT card?
l used to have a Femto card a few years back, and noticed a improvement, however, once l ditched my ATX psu for a HDPLEX set up, l could no longer detect a different between my Asus mb and the JCAT femto.
Any views, gladly accepted.

 

[Purité Audio]

Yes,
Keith

 

[Stellabagpuss]

Sorry, Can you expand, Yes, as a good or bad product?

 

[Purité Audio]

Is it a waste of money, yes.
Keith

 

[Stellabagpuss]

It it because the DAC reassembles the data?

 

[Veri]

It it because the DAC reassembles the data?

It's because it's snake oil, if you'd measure it it would show something like this
https://www.audiosciencereview.com/...ds/ifi-micro-iusb3-0-usb-filter-review.11284/

At best it does nothing
At worst it passes through yet another noise-injecting card

 

[somebodyelse]

The DAC buffers the data and uses a local clock when sending it from the buffer to the DAC chip. Jitter on the USB side is irrelevant - it doesn't reach the DAC chip. Similarly the DAC (whole box) will include power supply regulation that will take care of any noise within the expected range from USB ports, so super-clean power isn't required. If the DAC us USB powered it will almost always have a switching regulator inside anyway to make the -ve supply rail. The one thing that they could have done to make a significant difference, at least if the DAC has single ended outputs, would be galvanic isolation of the USB port to break the path for ground-related noise (which people often blame on USB power.) So far as I can tell they didn't do this though.

Note that there are some DACs that are sensitive to the USB power, and it clearly shows in the measurents - see the Modi 2 review for an example. This is a sign of a rubbish DAC, not that you need special USB ports.

 

[Stellabagpuss]

Thanks for such an in depth reply. Helps me understand the logic, and l originally suspected this, it kind of makes the purchase of any Jcat card pointless.

 

[SuicideSquid]

Thought I'd bump this old thread because all of a sudden, these guys are advertising everywhere on social media. $6000 linear power supply for PCs with only 60% efficiency (compared to modern switching power supplies that are around 90% efficient for $150), USB cards that eliminate non-existent noise, etc.

I tried to pin these guys down on whether they had any evidence to substantiate their claims. They proceeded to make more claims, claiming claims were evidence. Fun.

Here's the thread, if you're interested

Absolute nonsense. To be fair, it seems like they are genuinely deluded about their own products and not scam artists, but it's hard to tell for sure.

 

[Katji]

"I bought this as I didn't believe it would make a difference but it did. "
That's a classic.
...you would buy something, even though you don't believe it works...? LOL!

 

[SuicideSquid]

They're selling an "audiophile" SSD now. Apparently the 1s and 0s stored on their flash memory are higher-fidelity than the 1s and 0s stored on my flash memory.