3D "AIR" EQ - "Night EQ" PCB's Complete!

[raysolinski]

This looks cool!. Hats off to Kev and Peter...Are they be balanced in/out? One other thing...You can't take a log pot and use it backwards and think it is reverse log...it is about the taper of the pot, not the rotation of change.. Law C (reverse log) is tough to find but the taper is just right for most of our audio aplications. It made a huge difference when I put 50k reverse logs in my 312's (and adjusted the feedback resistor accordingly). Any pot will work but as Peter noted all the change will be at one end if you use linear or audio tapers...that said.

I am in for 2! :green:

Cheers,
Ray

 

[peterc]

Balanced or unbalanced I/O, set with jumpers.

Smallbear have 500k Rev log pots, not PCB mount though. See 2 posts up for mounting method. Linear & log types did not work very well at all.

I have suggested a group buy from Omeg, their pots are reasonably priced & great quality (plastic conductive) & they can give us a centre detent.

Peter

 

[Godders]

I already checked with Omeg Peter, 470K only.

Cheers

Nick

 

[jensenmann]

http://www.musikding.de/product_info.php?cPath=50_100&products_id=554

500k rev log pots, but not PCB mountable. If there´s enough interest I could try to talk this store into adding PCB mountable pots to his goods (I already did that successfully with PKES knobs).

big :sam: for you guys who made this project possible

 

[Ptownkid]

Whre is the correct BOM for peters boards, i saw the excel one but it's incomplete.

Also, I will most likely be doing an alpha order in the very near future.

 

[fucanay]

[quote author="Ptownkid"]Whre is the correct BOM for peters boards, i saw the excel one but it's incomplete.

Also, I will most likely be doing an alpha order in the very near future.[/quote]

When you do, please start a new thread. I'll order 12 of them from you. These seem rather rare.

Matt

 

[khstudio]

x

 

[khstudio]

x

 

[peterc]

I used Kevins last schematic....... It may sound a bit general, but thats all I have!

I added
4 x22R resistors,
4 x 22uF/25v caps,
12 x .1uF caps (2 per IC) &
2 x 22uF/63v caps for the input.

Peter

 

[fucanay]

Peter,

Any chance of an overlay graphic? That along with the schematic and parts list on the front page should lead us in the right direction.

Thanks

Matt

 

[audioforge]

looking the great pics kevin upload at grouddiy i see 4 ne5532(U1 U2 U3 U4) and 2 ne5534 (U5 U6). on schem and bom 5 ne5532 one ne5534......
did i miss something????
:?
audioforge

 

[khstudio]

The extra 5532 is for the "CLIP LED" which it NOT on Peters PCB.

It's probably the only thing missing.

 

[peterc]

Audioforge

I have changed the chips slightly, just allow for easier PCB layout. I only do single sided (making DS PCB's at home is a realPITA) so I did not use the 2nd half of the first 5532. I used a 5532 instead of a 5534 for the output section.

Peter

 

[clintrubber]

[quote author="jensenmann"]http://www.musikding.de/product_info.php?cPath=50_100&products_id=554

500k rev log pots, but not PCB mountable.[/quote]

Anyone brave enough to go for rotary switches i.s.o. all these rev-log pots ?

I'm seriously considering it, since that 'stereo-issue' keeps nagging a bit
(with pots like this it'll be hard to adjust left & right consistently).

Bye,

Peter

 

[sneakthief]

What about buying twelve alpha 500k rev log pots in addition to six regular dual alpha pots (any value) and sticking the 500k pot pcb's inside of the duals?

 

[clintrubber]

[quote author="sneakthief"]What about buying twelve alpha 500k rev log pots in addition to six regular dual alpha pots (any value) and sticking the 500k pot pcb's inside of the duals?[/quote]
I see what you mean, but I'm not sure that would guarantee good enough tracking (dual pots are usually pretty bad in that respect). You could match of course, but that might require quite a few pots to select from.

The switched rotary could also 'solve' the more or less minor issue of the somewhat strange EQ-topology: you need to have these rev-log pots dead center to have flat response for a band. Where is that point ? (could be solved by an additional trimmer, but that's also hassle).

I understood from KHstudio that there was also a mastering-version from this EQ that does use switched rotaries, and for a good reason.

So while at it, let's be at it and use switches

 

[sneakthief]

Yeah, it'd be important to match the dual pots.

As for rotaries, the question then becomes: how many positions and what values :wink:

Did you have any particular (affordable) rotaries in mind - eg. what about this? http://www.groupdiy.com/index.php?topic=22139&highlight=rotaries

 

[sonicwarrior]

Well, I ordered two stereo units, so I can try one with switches and one with pots. :green:

 

[sneakthief]

Or six of these (2x24) for 8 euro each?

http://www.uraltone.com/kauppa/product_info.php?products_id=1077

The only catch is that they supposedly won't fit in a 1u rack.

 

[clintrubber]

[quote author="sneakthief"]Yeah, it'd be important to match the dual pots.

As for rotaries, the question then becomes: how many positions and what values :wink:

Did you have any particular (affordable) rotaries in mind - eg. what about this? http://www.groupdiy.com/index.php?topic=22139&highlight=rotaries[/quote]
Not, not a specific type in mind yet - too bad it's a (rev)log-law otherwise not too elaborate tricks with one single-deck rotary and a boost/cut switch could be done.

There are other ways of course, but these will deviate too much from this design.

Regards,

Peter