Good question. Here are your answers. Might be more than you expected.
Output return loss of Legato, all by itself:
For some reason, the markers are not showing up. But anyway........you can see that the output return loss is around -45 dB, for most of the band, and stays below -30 dB, even out to 100 MHz.
What does this mean to you?
Easy. At -30 dB RL, only around 3% of any energy that hits that port will be reflected back to the source.
Most DACs and transports measure around -8 to -14 dB RL. That means that usually between 20% and 40% of the energy is reflected back to the source.
"Are there any better than -14 dB?"
Probably.
"Which ones?"
No idea.
"What causes the RL to be so poor?"
Lots of things: RCA jacks, inferior BNC jacks, wiring, PCB layout, the actual circuit itself contributes lots of it all by itself.
Unless you know how to handle those issues. OK, we can. But that is not the point of this. However, it is important to have that knowledge to understand what happens when you connect an adapter to a
Legato.OK, using a BNC-RCA, and then a RCA-BNC adapter, back-to-back.
Not exactly what you will encounter, but it is a close approximation of what your DAC with a RCA would look like. Assuming that it actually is 75 ohms. (Which it isn't! Sorry, hard to resist.)
Yes, it does go up some. Still, it stays below -30 dB, up to around 20 MHz. (Remember, your DAC does not look this good!)
"Well, that is all fine and dandy, but what happens when you add a cable to it? Isn't that what really matters?"
Sure, but now the cable becomes a dominant part of the picture. So, here is what happens when you stick a
U-byte cable onto it:
Not too bad..........close to -40 dB for most of the band. Below -30 dB all the way.
So, next the same adapter chain is added:
Yep..........looks worse. Stays below -30 dB only out to 20 MHz. Below -20 dB almost to 100 MHz. (Is your DAC this good??)
OK, the one you are really waiting for.............this is what it looks like with the included cable. Basically, a "cheap" version of the
U-byte. Translation: the wire it is made with is affordable. About 1/7 the price, per foot.
Hey, we are including if for free. C'mon, how much more do we have to do to sweeten the deal? (If you don't like the cable, then cut the connectors off and send them back for credit. They are not cheap.)
OK, "El-Cheapo", all by itself:
Alright..........not as good. Still, -26 dB is only 5% reflection.
And now with the adapters:
Well, how 'bout that.............not much worse with the adapters until you get to over 30 MHz.
So, like I have been saying...............it is a good cable for the money ($0.00), and adapters don't muck it up too bad.
But you have to keep in mind..........
"Yeah, yeah, we know, Mr. Wise-Guy..........our DACs don't measure that good. You made your point, now shut up!"
OK, I will.
Happy listening,
Pat
