EMU 1212M for measurements

[1audio]

Richard-
I'm not sure what you are driving towards. I have posted a way to confirm level accuracy at these low levels while making distortion measurements. Verifying ultra low distortion is extremely difficult. If you know your source is clean you can then verify the harmonics using the above techniques. I would use a CLT-1 and see what I get at the higher harmonics since its the only device I know if that is essentially free of HD3 and up. But its really clumsy to use.

 

[31697B]

Its easy question --- how good/accurate is the data at or near and below -100dB being shown by anyone here?

After looking at QA400, all are now suspect to me. [Unless they use a notch filter, I dont trust any of them down there]

Thx-RNMarsh

PS -- hope the CES was fun and good for you. Glad you are back.

A-P 2722 internal source-analyzer loop:

 

[jan.didden]

Just a thought: has anyone here ever used a lock-in amplifier to verify these low level harmonics?

Jan

 

[davada]

Just a thought: has anyone here ever used a lock-in amplifier to verify these low level harmonics?

Jan

Can you describe a procedure using a lock in amp?

David.

 

[Shinja]

I am planning to make 3stage cascaded twin-T notch filter...

 

[davada]

Very cool. Let us know how it works out.

I am planning to make 3stage cascaded twin-T notch filter...

 

[AndrewT]

..... has anyone here ever used a lock-in amplifier to verify these low level harmonics?.....

Can you describe a procedure using a lock in amp?
...................

What is a "lock-in amplifier"

 

[jan.didden]

Sorry, I didn't realise you guys were internet-challenged
Lock-in amplifier - Wikipedia, the free encyclopedia

Jan

 

[davada]

Sorry, I didn't realise you guys were internet-challenged
Lock-in amplifier - Wikipedia, the free encyclopedia

Jan

No just lazy.

I know what a lock in amplifier is just not sure what you have in mind for test.

 

[jan.didden]

No just lazy.

I know what a lock in amplifier is just not sure what you have in mind for test.

Ehhh? http://www.diyaudio.com/forums/equipment-tools/248720-emu-1212m-measurements-3.html#post3780049

Jan

 

[1audio]

I have one, a Krohn Hite 3800. I'm not sure it has the band rejection necessary to do this task but I'll give it a try soon. If your looking at the ADC I don't think there is a way to see inside one meaningfully.

 

[AndrewT]

Thanks for the link in post28.
I now know what a "lock-in amplifier" is and some of what it can do.

I do not appreciate the put down in the same post.

 

[jan.didden]

'Put down'? Lighten up Andrew, where's your sense of humor?

How do you think I feel when I have to do your google search?

Jan

 

[AndrewT]

I am barred from discussing how the Moderators view what you post and what I post.
I do not see it as humour. I see it as a personal remark that is a put down.

 

[jan.didden]

Well, it wasn't meant that way. My apologies.

Jan

 

[AndrewT]

Apology accepted.

I guess you never meant it as a put down, but that is what came out, especially with the icon appended.

 

[jan.didden]

Thanks. And I hope you do your own search next time, save me the frustration.

Jan

 

[31697B]

How about using the BenchMark ADC1 as a basic ADC of excellent performance and then add measurement software of your choosing?

THx-RNMarsh

 

[1audio]

The Benchmark would be good but its $1800 and not optimized for measurements. I will do the part swap on the Emu to see what I get. I think an analog upgrade board for the Juli may be the best option for the amateur. I will have demo boards for the ESS ADC soon. I'll see what the best option is.

Sent from my Nexus 7 using Tapatalk

 

[31697B]

Surely, not everyone on the planet is not willing to spend 1800 for a SOTA ADC? It should work very well for T&M with some small additions. It isn't DIY, though.
[I am waiting to receive/listen to the new DAC2 from BenchMark... quad 32 bit !! ]

The ESS should be interesting. I hope you find something that will be small and portable and won't require a notch filter.


Thx-RNMarsh