Speech Processor by Harry Lythall - SM0VPO_Correction to overlay

Hi again,
It is interesting about the comments regarding the compression and decay.

The Decay setting was to remove the popping you hear between words when you have "pregnant pauses". A moment of silence can cause the gin to rise again, so that you get a sort overload "pop" when you start talking. I found this was most noticeable when reading a list of numbers.

If you a microphone with a very high output then this can put the processor into compression much earlier. Try reducing the input level, then the processor will give you a range from light to heavy. perhaps I should have added an input level divider preset so that it would take a wide range of microphones?

BR Harry - sm0vpo

I made a double sided pcb using easyeda. please refer attached images.
point out errors and corrections if any.
If anyone need gerber file, revert me. i will send by email.
My email  vu3dxr@gmail.com

indrasung wrote:Hello. The ICLM358 was damage. The new one is works. But I do not heard any differences of setting compression or decay setting min to max.

Yes, no difference. Strange too. I use dynamic mic with preamp.

Hello. The ICLM358 was damage. The new one is works. But I do not heard any differences of setting compression or decay setting min to max.

Hello Sieben, thanks for your response...
I measured some voltage, how could the voltage between R14 and C3 around 1Volt ? I have change suspected the 1uF capacitor but the 1V still there.
The c8, c9 temporarily disconnected. IC was unplug. I check the track is also correct. I don't understand where is the error, please help.
Thanks

Well, it works without any such issues like warming LM, so the connections and short circuits should be checked along the board. The polarity as well too.

Also pay attention to pins of the bf245 mosfet. 


The right way of mosfet pins markings, although D&S are interchangeable on them, this is not this case, as the layout are right, the mosfet pins should be crossed depending on the mounting side before to be fitted on the board. As an example, S&D to be with cross fit pins. 
Long story short. 


And just general view.

Oh Yes Sieben, it was a small red x. I was not seeing it.
My compressor did not work, IC is warm after several minutes ON. Could someone help with some voltage or current test point.
Thanks

Hi.

Yes, and it was mentioned already also) Marked with "x" with an odd ground.

sm0vpo wrote:Thank you very much Sieben & indrasun, for finding the error. I don't know how it happened. I had the prototype in my hand when I created the drawing.
I have to follow the tracks on the prototype boards but the CAD is drawn from the component side.

BR Harry - sm0vpo

 Hello I am in the middle making this compressor, I just found another pcb error near diode ( decay port ), I think according to schematic it should not be grounded.
See attached overlay picture. My version was matrix pcb include another roger blip, ssb equalizer and this compressor.

Thank you very much Sieben & indrasun, for finding the error. I don't know how it happened. I had the prototype in my hand when I created the drawing.
I have to follow the tracks on the prototype boards but the CAD is drawn from the component side.

BR Harry - sm0vpo

Yes, I just also found it was an pcb error at pin 5 and 6 of IC.

Hello!

Have found some errors with Speech Processor.
http://sm0vpo.altervista.org/audio/mic_processor.htm

So, here is the corrections that should be made: 

The 5th and 6 pins of LM358 should be swapped.

Marked point should be avoided, as its grounded where it shouldn't. 

Hope it will be helpful.