seems what we have out there are hi distortion generators 1 to 2 percent! IMO garbage!!
so the question for someone that may know where to pickup an inexpensive basic generator with low IMO .01% distortion or better=??
Thanks
Lawrence
so the question for someone that may know where to pickup an inexpensive basic generator with low IMO .01% distortion or better=??
Thanks
Lawrence
If you want low distortion look for an "audio frequency oscillator" or "audio signal generator". Almost anything remotely affordable and called a "function generator" will have lots of distortion in the sine wave output.
This is about all that is available new and affordable. I recommend keeping an eye out for a good used one instead.
This is about all that is available new and affordable. I recommend keeping an eye out for a good used one instead.
Hi Lawrence,
Have you even looked at commercial audio generators that are available?
The only way I can see you achieving your goal is for you to build a few fixed frequency Wien bridge oscillators. If you know what you are doing, you can satisfy your distortion requirements. You will need a distortion analyzer and a good LCR meter so you can match capacitors and resistors. I have done this.
An HP 239A would do it, as would an HP 339A distortion measuring system. An 8903A or B would probably do it for you as well. Pick them up in the used market.
-Chris
Have you even looked at commercial audio generators that are available?
The only way I can see you achieving your goal is for you to build a few fixed frequency Wien bridge oscillators. If you know what you are doing, you can satisfy your distortion requirements. You will need a distortion analyzer and a good LCR meter so you can match capacitors and resistors. I have done this.
An HP 239A would do it, as would an HP 339A distortion measuring system. An 8903A or B would probably do it for you as well. Pick them up in the used market.
-Chris
Ultra low distortion ( 0.00001%) sine generator assembled and tested PCB
Current listing for is 1kHz and 10kHz. I think he will provide custom frequencies.
He is a member here who goes by vicnic. Here is a post that discusses his oscillator. http://www.diyaudio.com/forums/equi...on-audio-range-oscillator-21.html#post3116055
Here is another post of Victor's oscillator in a well done enclosure.
You will have to provide you own power supply and case.
Current listing for is 1kHz and 10kHz. I think he will provide custom frequencies.
He is a member here who goes by vicnic. Here is a post that discusses his oscillator. http://www.diyaudio.com/forums/equi...on-audio-range-oscillator-21.html#post3116055
Here is another post of Victor's oscillator in a well done enclosure.
You will have to provide you own power supply and case.
Sorry, I forgot the active link. Try again.
Here is another post of Victor's oscillator in a well done enclosure.
Victors oscillators and the "rechargeable batteries" trick
Here is another post of Victor's oscillator in a well done enclosure.
Victors oscillators and the "rechargeable batteries" trick
The generator of post #9 from a reliable supplier: Function generator - Buy Cheap Arduino Compatible Kits & DIY Kits - From Banggood
What is wrong with soundcards? A sine wave generated from your pc or pad is not ok? The distortion can be lowered from the gain within the sine wave program right?
Thats what I used to measure voltage and gain from my speaker output, using a 1khz sine wave.
even in mp3:
that shows a spur as the 1st limit - you can measure around spurs if you just want THD, IMD
A sine wave oscillator is easier, just twist the level control to adjust that. Accepting higher THD will allow you to twist the frequency control to change that. The old XR2206 and 8038 are chips you can built a function generator around and are the basis of most the function generators sold for over 30 years. Look them up and you will find all kinds of schematics for generators. THD is generally less than 1%, and that is the price of convenience. If you need low distortion, then spot frequency Wien bridge oscillators are the way to go. Put a volume control (linear taper, or "B") ahead of a buffer to drive the output. By using J-Fet stabilizers you can get extremely low distortion (as opposed to the lamp type). I have built both kinds, and bought both kinds.
-Chris
-Chris
Lawrence:
Here is the link and thread for Victor's Oscillators.
http://www.diyaudio.com/forums/equi...power-supply-victors-low-thd-oscillators.html
Here is the link and thread for Victor's Oscillators.
http://www.diyaudio.com/forums/equi...power-supply-victors-low-thd-oscillators.html
Last edited by a moderator:
- Status
- Not open for further replies.