LT AN67 Ultralow THD 10kHz sine oscillator group buy.

[Frex]

Hi Ken, send me your personal e-mail address by PM, i will send
you the invoice.
Regards.

Frex.

[Frex]

Hi Ken, invoice sent.

Some of bare PCB my others DIY projects are also available for sale :
EOSC10KV2 - 10kHz ultra-low THD super sine oscillator.
AA5381V1 - 24bits/192kHz Measurement High performance Analog to digital Converter.
ERMSDCV2 - DC-1MHz RMS to DC converter & 80dB Ultra Low noise Amplifier.

Frex

[Stefan0815]

Hello, are there still some PCB's left?
Or is there an free eagle file out there?

[Frex]

Hello,

A new PCB batch has been ordered, and some PCB are now available
for sale.
Price not changed ; 30€ including worldwide shipping.
A very complete design folder is send by e-mail to each bare PCB buyers,
as soon Paypal payment done.
Paypal only.
Regards.

Frex.

[Stefan0815]

I want to tune the Frequency around 3.33khz.
Am i right to multiply the 390pF caps and the 10000pF caps by 3?
The phase shifter circuit (made of 470pf and 2,2n) should be untoched in my opinion.
I made a short simulation with simmetrix, the problem was that i was not able to find the "peak of 5db" at 10khz in the transfair function. So I am not able to check the same thing with 1200pf.

Your documentation is nice! If someone is interested, i can write down my Farnell shopping list (with order Numbers).

What minimum Input Voltage do you suggest with the low noise voltage regulator? Is +-15V enought?

[Frex]

Hello Stephan,

If you want change the oscillator frequency, just modify the Ra/Ca and Rb/Cb network, not others parts.
You can see on the schematic that Fo is 1/(2PIRC) with R=Ra=Rb and C=Ca=Cb.
Don't change the 390pF capacitor.

About my documentation, thank you.
I would be happy to add your Farnell shopping list with order number to my design folder, of course.

About the minimum voltage, you can use two 6F22 battery (9V) if you connect them on the X10/X11/X12 pads.
If you use a main PSU (from 110/220V), you need at least +/-15v for proper operation of the low noise regulator (you must use X5/X6/X7 inputs pads).
Good luck.
Regards.

Frex.

[Stefan0815]

The important thing of the amplifier is, that it does a big phasehift at the resonant frequency.
If i don't change this part of the circuit i will lose performance in gain (but i don't know by what effect the peak is caused) and in phase slope.

I should install LT spice instead of simmetrix.

[Frex]

Hello,

You can find the 390pF capacitor here.
Available and low cost.

Changing this capacitor will no affect the oscillator frequency but could make it
unstable...Be caerful with that.

Frex.

[Stefan0815]

I installed LTspice. It seems much better than Simetrix.
Here is my first simulation.
The 10khz one is with an 20000p Input cap, the 3khz version is with an 60000p cap.
As i can immagine, the input cap (part of the wien bridge) and the 50pF cap (Part of the LT1007 opamp) forms a capacitive voltage devider So the low freq gain rises!

The gain plot looks more stable, but i must think about the phase reserve....

[muzeau]

Hello,

Are there still some PCB's left?

Regards