if its the Virtins software upgrade, that was released yesterday as ver 3.9
Downloads - PC Sound Card Oscilloscope, Spectrum Analyzer, Signal Generator, Data Logger, Real Time Audio Analyzer | Virtins Technology
quite a list of changes
it is an included upgrade for current users. (that means free)
you could also see #618
GB for Virtins MI Pro for RTX6001 autoranging/autoscaling & for soundcard end users
Cheers
Alan
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Hi All
So as I have time due to lockdown I am able to build my autoranger by Jan.
I am a little confused about parts I have ordered in the past which I am comparing to an updated BOM.
I have a Analog Devices AD536AJDZ True RMS-DC Converter 14-Pin SBCDIP which seems to be changed to AD536AJQ which is out of stock, will what I have be ok to use?
Also on my BOM it say D3 and D5 is Z9.1 which makes no sense to me as there is no comment on what this actually is?
Any help and advice on OPAMPS used successfully and generally advice on this project would be appreciated.
Thanks!
Vish
So as I have time due to lockdown I am able to build my autoranger by Jan.
I am a little confused about parts I have ordered in the past which I am comparing to an updated BOM.
I have a Analog Devices AD536AJDZ True RMS-DC Converter 14-Pin SBCDIP which seems to be changed to AD536AJQ which is out of stock, will what I have be ok to use?
Also on my BOM it say D3 and D5 is Z9.1 which makes no sense to me as there is no comment on what this actually is?
Any help and advice on OPAMPS used successfully and generally advice on this project would be appreciated.
Thanks!
Vish
The RMS-DC converter is OK.
For the opamps I recommend OPA1656 for the dual, and an LME49710, or any other 'good' low distortion opamp for the single.
D3 and D5 set the max output level to protect the input of the soundcard. Normal small 0.5W zeners are OK. If your soundcard has a max allowed input level that is lower, you can change D3 and D5 to a lower value. The max peak output level of the AR is the zener voltage +0.6V.
So, for instance, the 9.1 zener allows peak output of ~9.7V which is about 6.8Vrms.
Jan
For the opamps I recommend OPA1656 for the dual, and an LME49710, or any other 'good' low distortion opamp for the single.
D3 and D5 set the max output level to protect the input of the soundcard. Normal small 0.5W zeners are OK. If your soundcard has a max allowed input level that is lower, you can change D3 and D5 to a lower value. The max peak output level of the AR is the zener voltage +0.6V.
So, for instance, the 9.1 zener allows peak output of ~9.7V which is about 6.8Vrms.
Jan
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Thanks Jan so any 9.1V 0.5W Zener diode will suffice, I have yet to buy a decent soundcard any suggestions for an external soundcard that works well with this AR?
As to the opamps do I need to change any parts to accept the ones you suggested? Can I also just stick to the BOM parts and just get it built and working and at a later stage try different opamps?
You will have to excuse my lack of knowledge in these areas, first time building something like this.
As to the opamps do I need to change any parts to accept the ones you suggested? Can I also just stick to the BOM parts and just get it built and working and at a later stage try different opamps?
You will have to excuse my lack of knowledge in these areas, first time building something like this.
Nice one Jan, after all the work you have put in to your project it is well deserved.
Best regards
Mike
No problem asking these things, I am also standing on other people's shoulders!
Use good quality sockets for the opamps so you can swap. The OPA1656, the lowest distortion opamp on the planet at this time, comes in a surface mount package so you'd need an adapter for it. But you can build it up with say an LM4562 or NE5532 and an NE5534 for the single to get it all working and correctly operating. Focus on that, otherwise you keep going around in circles.
Once you have that milestone, we can look further.
Jan
... and another blog about constructing the autoranger. The pictures are better than mine ...
Archimago's Musings: It's Alive! The Linear Audio Autoranger MK II...
Jan
Archimago's Musings: It's Alive! The Linear Audio Autoranger MK II...
Jan
... and another blog about constructing the autoranger. The pictures are better than mine ...
Jan
About audioXpress, the "Figure 3: The Autoranger Mk II shows astonishingly low distortion and noise, requiring a state-of-the-art audio analyzer to characterize."
Is this spectrum SE Input to Balanced output?
Hp
Hp do you have a link?
Edit - found it: Fresh From the Bench: The Linear Audio Autoranger Mk II Measurement Interface | audioXpress
I am not sure but looking at the 2nd I would say se in bal out. An educated guess ;-)
Jan
Edit - found it: Fresh From the Bench: The Linear Audio Autoranger Mk II Measurement Interface | audioXpress
I am not sure but looking at the 2nd I would say se in bal out. An educated guess ;-)
Jan
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Yes, while having a 60Hz hum...
IMHO, you should provide real spectrum plots as using SE Input to Balanced Output. Balanced too!!
While some HW gear (RTX, RME ADI-2 pro) deal really with balanced by design and SE input with a DUT gets with earth connection is a
Hp
Hello Jan
I finally sorted out why I was blowing input fuses in my AutoRanger Mk.II despite having increased the fuse value from 50mA to 100mA.
The culprit was applying a large value input signal while the AutoRanger was set for a low level input signal. Specifically turning on the sine generator with the amplifier set for a high power level in order to take a THD measurement using ARTA. This consistently blows fuses.
If I either bring the input level up gradually so that the AutoRanger can switch ranges OR preset the AutoRanger to an appropriate level of attenuation using the HOLD function, the problem with fuses does not seem to present itself.
Perhaps this is a matter of which you are already aware.
Best regards,
Mike
I finally sorted out why I was blowing input fuses in my AutoRanger Mk.II despite having increased the fuse value from 50mA to 100mA.
The culprit was applying a large value input signal while the AutoRanger was set for a low level input signal. Specifically turning on the sine generator with the amplifier set for a high power level in order to take a THD measurement using ARTA. This consistently blows fuses.
If I either bring the input level up gradually so that the AutoRanger can switch ranges OR preset the AutoRanger to an appropriate level of attenuation using the HOLD function, the problem with fuses does not seem to present itself.
Perhaps this is a matter of which you are already aware.
Best regards,
Mike
Autoranger MkII is a great tool, could be even better.
But those results are way better anyway comparing to old NE5532 or NE5534.
I use 10 uF MLCC capacitors right on the PS pins of op amps, with 0.033 uF C0G ceramic capacitors in parallel to lower possible noises even deeper.
As a tool, Autoranger MkII can be used with Victor's generator (-140dB at 1 kHz). I would like to thank you guys again for being extremely valuable diyforum members!
Please keep you great work going!
Thanks for your hard work, Jan. Yes, you are absolutely correct, we can use better op amps with significantly better distortions results. I didn't try OPA1656 yet being quite satisfied with OPA1611 - actually per datasheet it beats OPA1656 having 0.000015% (-136.5 dB) THD at 1 kHz comparing to 0.000029% (-131dB) for OPA1656. It also has significantly lower voltage noise level at 1.1 nV/sqr Hz at 1 kHz comparing to about 2.9 nV/sqr Hz for OPA1656 (look at the graph in the datasheet for 1 kHz result). Please also note that being unity gain stable, it could eliminate some unpredictable results and be less sensitive to the PBC layout tracing.
But those results are way better anyway comparing to old NE5532 or NE5534.
I use 10 uF MLCC capacitors right on the PS pins of op amps, with 0.033 uF C0G ceramic capacitors in parallel to lower possible noises even deeper.
As a tool, Autoranger MkII can be used with Victor's generator (-140dB at 1 kHz). I would like to thank you guys again for being extremely valuable diyforum members!
Please keep you great work going!
