Barry Porter "Net EQ"

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5v333

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If you buy a 19" case you prob get a blank front panel with it.
You could use that for a try out before you order your design from the panel manufacturer.
Its so easy to miss something out.
 

petermontg

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Is there any boards floating around or does anybody know where to pick a set this weather.

Best
Peter
 

weiss

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Is it correct that the onboard variable hpf is going from 75 to 200 hz?
what would be the easiest way to lower the values when using a potentiometer?
 

5v333

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Hello.

The schematic i have on my computer states clearly 15hz-400hz.

The filter is made up of two sets of RC (12db/oct). R varys when you turn the dual pot.

If you want higher min/max freq, lower the capacitors.
For lower min/max, increase the caps.


 

weiss

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5v333 said:
Hello.

The schematic i have on my computer states clearly 15hz-400hz.

The filter is made up of two sets of RC (12db/oct). R varys when you turn the dual pot.

If you want higher min/max freq, lower the capacitors.
For lower min/max, increase the caps.
Thank you very much !
 

weiss

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anyone ever tried taking lundahl transformers into the circuit?
i saw hcl doing this with the thermos!
 

duende

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Dec 16, 2016
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Hello,

I'am building a Net eq and i would like to know what switch is the best for this circuit , shorting or non-shorting ?

Thanks
 

trashcanman

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For those wanting all the files for this you can download them from this link.
https://we.tl/t-3vQVRxHjak
 

alexc

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Sep 21, 2004
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Hobart
weiss said:
finally done with my build.





Lordy - that is the most awesome diy eq I think I have ever seen  :)

Congrats and much, much aclaim.  I mean, just wow man!
 

weiss

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Would be thankful for some input about my remaining issues with my Net EQ. I already managed to get rid of some issues but these i couldn't figure out..  :-\

1: The Low-Mid section Gain seems not to have any effect on BOTH channels (L+R). I checked the wiring but couldn't find any shorts or bad solder points on the gain potentiometers. Where would i have to search if both channels are affected?

2: The HPF frequency on channel one seems to have a wrong behaviour: When i turn on the highpass filter it immediately cuts very high freq completely CCW on the freq potentiometer. When i turn the potentiometer further CW the cut freq decreases and then increases again towards the end. I used the same potentiometer on both channels..

3: Also on the left channel the peak mode in the high frequency section doesn't work. The right channel as well as the shelf mode are not affected by this. Wiring issue?

appreciate the help!!
 

Gold

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weiss said:
1: The Low-Mid section Gain seems not to have any effect on BOTH channels (L+R). I checked the wiring but couldn't find any shorts or bad solder points on the gain potentiometers. Where would i have to search if both channels are affected?

To eliminate the switch or pot I twist resistors together in a mock up.  Twist two 5K resistors together at one end. The other end of One resistor  goes to Cut. The other resistor goes  to boost. Twist a wire to the junction of the 5K resistors. This is the center tap ground connection. Then make a wire for the wiper. This way you either will get full boost or cut when touching the Threshold wire to the end of the resistors or flat. If it works as expected it’s probably a switch wiring issue.

3: Also on the left channel the peak mode in the high frequency section doesn't work. The right channel as well as the shelf mode are not affected by this. Wiring issue?

appreciate the help!!

I’d look at the relay first. It may be stuck.
 

weiss

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Gold said:
To eliminate the switch or pot I twist resistors together in a mock up.  Twist two 5K resistors together at one end. The other end of One resistor  goes to Cut. The other resistor goes  to boost. Twist a wire to the junction of the 5K resistors. This is the center tap ground connection. Then make a wire for the wiper. This way you either will get full boost or cut when touching the Threshold wire to the end of the resistors or flat. If it works as expected it’s probably a switch wiring issue.

thanks for the tip, i'll start with that.
stupid if i messed it up on both sides..  ::)


Gold said:
I’d look at the relay first. It may be stuck.

when i can hear it click it means it's working right?  ???

 

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