I disagree in the sense that this must have been a very early AP. All current AP's starting with the 27xx series can measure any individual harmonic up to 10th in any combination, with or without noise.
The multitone measurement gives HD, THD, THD+N, Noise, IM and a few other things from a single sweep.
Jan
The multitone measurement gives HD, THD, THD+N, Noise, IM and a few other things from a single sweep.
Jan
THD+N
Bob Bauman (at Lynx) used a 2522 model that does have provisions for an FFT. Nevertheless he preferred to publish only THD+N figures. (which hides a stupid design flaw of the L22. That was the reason to start a discussion with him)
Cheers,
E.
Hi Jan,
Bob Bauman (at Lynx) used a 2522 model that does have provisions for an FFT. Nevertheless he preferred to publish only THD+N figures. (which hides a stupid design flaw of the L22. That was the reason to start a discussion with him)
Cheers,
E.
Absolutely!
Hi Edmond,
They should have published both specs than. You are right in that THD only would hide a power supply issue and general noise in the system. Publishing both figures would give people some valuable information (or publishing the sweep without excessive smoothing).
-Chris
Hi Chris,
It was the noise from THD+N that hided a huge increase of distortion (by some 40dB) at low frequencies*. It was caused by a 100nF XR5 cap in the signal path. See also this post.
Cheers,
E.
* Only in single ended mode.
The link to the thread that is linked goes to a dead web site. Can you point me to some directions on mods to the L22 to address the X7R embarrassment?
It works for me, but my forum settings are for 50 pages per page. If yours are different, you might try changing and try again.
Worst case you can find it manually. It's post #4563 in this thread.
ETA: Oh a link that that post goes to, at data-odyssey.nl - yeah, it's not in archive.org either.
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L22 flaw
Indeed the link goes to a dead end because I've deleted it. Should I create a new thread on this forum?
Cheers,
E.
Hi Demian,
Indeed the link goes to a dead end because I've deleted it. Should I create a new thread on this forum?
Cheers,
E.
Yes, a new thread would be most useful. First upgrades to the L22 if there are any. I may be able to contribute upgrades for the Emu 1212m. The 1616m are a little too hard to upgrade successfully. I also did some work on the ESI Juli@ card.
PCI cards still have some key advantages in latency over USB.
PCI cards still have some key advantages in latency over USB.
Hi Edmond,
A rather silly mistake as a capacitor like that is going to cause distortion. All it means is that their audio engineers are still learning. I wonder if the applications circuit had that capacitor in it.
-Chris
A rather silly mistake as a capacitor like that is going to cause distortion. All it means is that their audio engineers are still learning. I wonder if the applications circuit had that capacitor in it.
-Chris
Hi DemiaN,
I think I have an EMU 1616m I was using before that is still mounted in my old bench computer. A thread on that one as well would be welcome.
-Chris
I think I have an EMU 1616m I was using before that is still mounted in my old bench computer. A thread on that one as well would be welcome.
-Chris
The app circuit would be for the AK5394A. I found some other "mistakes" on it and got a 10-15 dB improvement in distortion so its possible there are others but more likely its an effort to shrink the footprint of the circuit. I checked the demo board and it has some tantalum and ceramic bypass caps but no ceramics in the audiopath.
Dios mio, the EMU cards and the Windows environment are a nightmare.
Straight from Elm Street
Straight from Elm Street
Hi Demian,
Please have a look at this.
Hi Chris,
Actually I'm also highly amazed about this mistake, as the guys at Lynx are not that stupid. It is not due a faulty applications note, because the proprietary balanced line output stage contains that evil capacitor.
Cheers,
E.
The EMU stuff is not easy to deal with but it has very good ADC's and a lot of flexibility. The 1616m is an external box that is well isolated from the PC with 8 in and 8 out using 4 AK5394A's. That makes it much more interesting.
It could be as mundane as a purchasing manager who found an alternative for 1/4 price ;-)
Jan
Hi Demian,
I got my model number wrong then, It must be a 1212. The 1616 does sound far more interesting!
Since I do have an RTX, these efforts would be limited to things I own already.
-Chris
Edit: Hi Jan, I have seen that situation with audio equipment, so it isn't far fetched at all.
Hi Edmond, Thank you sir! Also, not too surprising. Not from my experience at least.
I got my model number wrong then, It must be a 1212. The 1616 does sound far more interesting!
Since I do have an RTX, these efforts would be limited to things I own already.
-Chris
Edit: Hi Jan, I have seen that situation with audio equipment, so it isn't far fetched at all.
Hi Edmond, Thank you sir! Also, not too surprising. Not from my experience at least.
