DIY Analog-to-Digital Converter project.Audio measurements tool

[Frex]

Hello,

EUVL,
I prefer organize a second group buy for the oscillator pcb.
But for this next group buy, and mostly for simplify the order and to consider the needed time to do it, i don't ask the same price.
As the previous group, i start only the order if ten or more printed circuits board is asked.

The price for each PCB would be 30€ for one. This price will include;

• New order to PCB for at least ten boards.
• Customs fees to my country
• A good packing for the PCB (bubble envelope)
• Shipping cost to you in international priority letter (no insurance).
• The Paypal fees when you payed me.
• A little contribution to this work.

I think it stays again at avery reasonable price.

All Diyers interested could send me a private message,
if you are enough i will open a new wiki for this new group buy.


AR2,

Thank you for your interest of the AA5381 ADC.

I can also organize a group buy for the ADC.
If a least 10 boards is ordered, i can sale it 40€ each,
including all, as the 2nd oscillator group buy.
It's a very good price for a 4 layers class 5 PCB!
Of course, all design files will be send to each buyers.

DIYers interested must send me a PM, for be added to a "waiting list".
The order can be done if a least 10 boards is asked.

Regards.


Frex.

[grenert]

I just wanted to say I've received my oscillator boards and they are really nice quality. Thanks!

[bbp]

Thanks to Frex's thread

I can't wait to build my own AN-67 generator ^_^
so, it come out after 2 days hard work
I test it with E-MU 1212M, balanced mono mode

It is really an excellent sinewave generator but only the 50Hz noise is not meet my expectation.

[jackinnj]

Originally Posted by bbp

Thanks to Frex's thread

It is really an excellent sinewave generator but only the 50Hz noise is not meet my expectation.

It MUST be placed in a steel container - like a cookie tin -- aluminum won't work.

Ordinary steel has its short comings, but should get the 50Hz signal down by 60dB or so. For more attenuation you can use a container within a container.

The oscillator has provision for balanced output -- if using this consider dual shielded twisted pair.

You might want to put 220u/100n on the power leads where they join the PCB -- you'll pick up a lot of 50/60Hz from the power leads.

[Frex]

Hello,

I have finish the wiring and machining my own oscillator.It work very fine !
A little picture of what it look like.
Some measurements will come later .

Frex.

PS: bbp, your job is very cool .

[iko]

Very nice Frex! What are you using for psu?

[Frex]

I terminate at this time a new +/-15V PSU based on SSR01/SSR02 ultra low noise PSU boards from P.Sjostrom. For the best performance, we can also use batteries. I find this last solution not very convenient.

Frex.

[EUVL]

Would you perhaps also be kind enough to explain your trimming procedure and measurement method ?

How is the 2nd Group Buy going ?
(I have sent you a PM a while ago.)


Thx,
Patrick

[bbp]

Originally Posted by jackinnj

It MUST be placed in a steel container - like a cookie tin -- aluminum won't work.

Ordinary steel has its short comings, but should get the 50Hz signal down by 60dB or so. For more attenuation you can use a container within a container.

The oscillator has provision for balanced output -- if using this consider dual shielded twisted pair.

You might want to put 220u/100n on the power leads where they join the PCB -- you'll pick up a lot of 50/60Hz from the power leads.

Hi Jackinnj, I've sent the PCB file to the manufacture for a better factory made PCB, maybe the PCB will arrive the day after tomorrow.
As I know, you're the first person who made this osillator and post the test result public. I've read your post about 3~4years ago ^_^

I add a XLR connector in that version of PCB, which is not contained in this hand-made PCB
I'm going to use two 7.2V NI-CD batterys as the power supply, the batterys will not cost too much in my local market. Low-noise PSU based on OP-AMP is another good choice, like JSR series.

I don't know the wideband noise will increase or not if a high-pass filter is added following the oscillator, AD797 is a good choice I think.

My ADC in 1212M only performs -113dBFS residual noise @48K sampling rate with the input terminating. So, most of the time, I will use my VCS(Volume Control System) as a authentic-attenuator between the source and ADC. Once I set the attenuation to -20dB,the 50Hz noise and its harmonic freqency noise will be also cut-down 20dB.

compare the two graghic
original,oscillator provides 1Vrms balanced


second,oscillator provides 4Vrms balanced and the VCS attenated to 1Vrms





best regards

[bbp]

Originally Posted by Frex

Hello,

I have finish the wiring and machining my own oscillator.It work very fine !
A little picture of what it look like.
Some measurements will come later .

Frex.

PS: bbp, your job is very cool .

Thanks Frex,

I like your LAYOUT, you did a really great job ^_^
the position of components are reasonable, the axial capacitors look beautiful too

I done another ADC layout for my graduation project too, which is also based on CS5381KZ, maybe 5~6 days I can assembled the ADC and make the measurement.
The ADC part of 1212M is really good, but I want a ADC apart from my PC board ^_^

have a nice day
best regards
Lu