Barry Porter "Net EQ"

[mata_haze]

Sorry guys, I am trying to get my head around this project and collect data.
is there a BOM, a PDF or something about this at all (apart from the PERFECT HARPO spread sheet).
something with description, calibration or something like this.

also how do you achieve the cutting and boosting switch feature (ala manley)

Mattia.

 

[mata_haze]

found the cut/boost option I did not know there was another thread.
still no BOM tho...

Mattia.

 

[protools]

Here the BOM...

 

[Biasrocks]

That appears to be the preliminary BOM I put together a while ago.

I asked for additional input, none was given.

Hence V0.

Regards,
Mark

 

[dagoose]

That appears to be the preliminary BOM I put together a while ago.

I asked for additional input, none was given.

Hence V0.

Regards,
Mark

I used it and found no problem IIRC so go ahead and use it!

 

[mastertaenia]

Can dagoose post the plan for the faceplate?

 

[dagoose]

Can dagoose post the plan for the faceplate?

No, i'm sorry.. maybe later but not now.

 

[Treelady]

Respectfully, mastertaenia why don't you do your own faceplate?  Set things up the way you want them to look.  What if you choose different frequencies?  etc...

 

[petermontg]

Any thoughts of where to find the best PSU parts. Will one of the PSUniversal kits suffice for this EQ.

 

[Treelady]

Petermontg,

Please put your location (continent or country is fine) in your profile or in your post.  The answer on getting power supply parts (with lower shipping costs) is often tied to where you are and what your local power situation is.

Best, GH

 

[petermontg]

I was thinking that alright I am in Ireland Euro psu. Will update now.

 

[Assistant]

ok, here´s my BP Eq....almost finished, frontpanel is not done yet.

I got everything working except low and hi peaking bands acting a bit strange...

i get way more boost when i switch from hi-shelf to peak and there´s a loud feedback noise in some positions but only on the left channel hi peak and right channel hi and lo peak.

also with no input, the q on highest setting and gain boost to max, i get some sort of oscillation which follows the selected frequency.
goes away as soon as i switch to shelf, so i´m guessing the high peaking bands are somehow out of their range?
any ideas?

high and low shelves and the normal mid bands working fine.

and the low cut is not working at all, have to check again, only wired one yet...maybe i got the wires reversed

cheers
nils

 

[Assistant]

another picture...

 

[Assistant]

Ok, i had an 100k Resistor at R 62, where it should be 10k.
i was using the "net eq component overlay" that is floating around here...small typo there!

now the hi peak bands are working correctly!  8)

not sure about the loud noise i get at some positions, i guess the switches are faulty. when i bend it a bit, it goes away.

 

[petermontg]

Anybody build this with band bypass would be a option I would like to add, before I order my front pate. Details?

 

[petermontg]

Any body willing to help me connect switches to the board, am at a loss what goes where.

 

[ruairioflaherty]

Any body willing to help me connect switches to the board, am at a loss what goes where.

Your rotary switches (if that's what you mean when you say switches) will replace the pots that would normally wire to the board.  You have wiper, the center tap and both ends of the resistor ladder.

 

[petermontg]

Any body willing to help me connect switches to the board, am at a loss what goes where.

Your rotary switches (if that's what you mean when you say switches) will replace the pots that would normally wire to the board.  You have wiper, the center tap and both ends of the resistor ladder.

Thanks R. I know that much. Just where do these connect on the board is confusing me. Do I need the overlay.

To which solder point in the given section is what I mean.

 

[Harpo]

Any body willing to help me connect switches to the board, am at a loss what goes where.

Your rotary switches (if that's what you mean when you say switches) will replace the pots that would normally wire to the board.  You have wiper, the center tap and both ends of the resistor ladder.

Thanks R. I know that much. Just where do these connect on the board is confusing me. Do I need the overlay.

To which solder point in the given section is what I mean.

Peter, you don't need the overlay, but it helps to identify parts. IIRC you built the pot substitutions (dunno if for all parameters A/F/Q) according to my excel sheet.
If for all, P4, P6abc, P7, P9ab, P10, P12ab, P13 and P15abc aren't pots anymore, but switched rheostats.
Have a look at Barrys schematic, the pcb silkscreen, my substitution schematic and my excel file.

FI frequency setting pot P12 for the 400Hz-4kHz range (this is a stereo pot, so you have a variable resistor in section A and another one in section B). The bottom row rightmost pin of the pot P12a (the CW position) connects to U15A-pin1. Instead of the pot you now connect the 1st deck switch pole to this point. The last one side connected resistor (1210 ohm), connecting to your highest switch position (depending on switch maybe pos.12, 23 or 24) connects to the bottom row center pin of P12. The bottom row left side pin stays unconnected. Same goes for the other pot section P12b that gets substituted with the other deck of your switched resistor assembly (switch pole to the right, last step position resistor to center hole, left side hole unconnected). From my excel sheet either jumper R83 and R58 (these are already part of the switched resistors) or fit these last step 1k21 resistors here instead so they don't hang lose on your switches. Don't populate R111 and R112. Use cap values from excel file (IE 33nF for C61 and C84).
Same procedure for the other frequency setting switch asemblies.

FI Q setting mono pot P10. Jumper the right and center hole on pcb and connect switch pole and switch position 1 to this jumper. Last switch position resistor goes to the left side hole. Jumper R110 or fit this last switch position resistor here instead so it doesn't hang lose on your Q switch.
Same procedure for the other Q setting switch asemblies.

FI amplitude setting center tapped pot P11. Rightmost of the 4 holes goes to your +/-0dB probably center switch position on your switch. Switch pin1 goes to the leftmost hole on pcb, switch pole connects to 2nd from left hole and highest switch position connects to remaining 2nd from right hole. You could have a on/off switch between pcb and your switch pole for your wanted band bypass.

Hope this helped a little.
Harpo

 

[petermontg]

Thank you Harpo, you are a true gentleman.

I am at the last hurdle so will post back when I am finished, which should be soon.

Thanks again harpo.