Full Range EQ

[c10]

Yes! Was wondering more about a specific model/part. Options are rather plentiful ;-)

 

[Nelson Pass]

It's just there to filter noise from the supply. Anything reasonable will do.

 

[c10]

Thanks again!

 

[dajack761]

I’m a little late to the party.. I just ordered mine. Did I miss the up to date BOM or should cobble a parts list?

 

[G600]

Here is the circuit I used. I also stuffed the enclosures with Polyfill.

You may find R3 having too much bottom, but you can increase the value to remove that.

Did any body made changes for Lii Silver10 ?
I'm planning to EQ it in an open baffle use.
Should I omit P1 if I'm following Nelson's "starting point" circuit (bass reflex use)?

 

[G600]

I’m a little late to the party.. I just ordered mine. Did I miss the up to date BOM or should cobble a parts list?

I don't think there's a BOM because many parts have to be calculated with microcap following your in situ measurements (see Nelsons article in post 1).

 

[Robert k]

Just finished soldering the board but when I tested it out the EQ is not working. Can’t figure out why it’s not working and don’t know how to trouble shoot it. Any suggestions?

 

[claudio52]

What voltage do you measure on R7 and between Q1 and Q2? You can measure this voltage on one end of R3. It should be about half the supply voltage.

 

[Robert k]

Im getting very low voltage on R7 or R3. 0.008v The led is not illuminating either.

I’ve checked all the solder joints, resistor values and Capacitor polarity. I can’t find anything out of place.

 

[Zen Mod]

rail voltage is?

 

[Robert k]

24 volts

 

[Zen Mod]

confirm that with DVM at both 1000uF caps

inform here

 

[Robert k]

Very grateful for your help, I’m getting 11 volts at the first capacitor and zero at the second.

 

[pinholer]

Check the value of the 47.5 ohm resistors in the RC filter at the power input. They look like 47.5k ohm resistors to me.

 

[Robert k]

Thank you, I realise where I’ve gone wrong, I have 47.5 k ohm resistors in place instead of 47.5 ohm.

Hopefully that’ll sort it out once I get the right values in, unfortunately don’t have any in my stash at the moment. Will update

 

[Nelson Pass]

Any similar value will work fine.

 

[Faizal Ali]

@Nelson Pass, do you have any recommended curves for the Lowther PM6A?

 

[Robert k]

After replacing the resistors with correct values I have the Full Range EQ working now, it sounds really awesome, I’m getting a bit of buzz in the background that the EQ seems to to introducing ie it’s no longer there when I remove it. Any suggestions as to what it could be?

I’ve populated the board according to the example in the Nelson Pass article. Im using a Meanwell power supply and running it between my laptop and an Amp camp amp mini amplifier, speakers are fostex full range speakers.

 

[Robert k]

Touching any component on the board makes the buzzing louder, what could cause this issue? Anyone have any idea why?

 

[Zen Mod]

pics