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

[Purusha]

My goal is to basically build the "AIR" band & share it with the group.

Why not the whole thing?

 

[khstudio]

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[khstudio]

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[Purusha]

The schematic I'm making (for now) will only be the fixed 2.5k band & the switchable shelf = 5k, 10k, 20k, 40k.

Kevin, not bad idea at all :thumb:

Maybe I could make some nice 2U cases for 8ch. of 2.5k band & the switchable shelf = 5k, 10k, 20k, 40k. We could organize some PCBs order and have a group buy. I know how this AIR sounds and I liked it from the first moment I heard it.

 

[Purusha]

Although the SUB part sound very usefull too.

 

[khstudio]

[quote author="Purusha"]Although the SUB part sound very usefull too.[/quote]

Yeah, the sub DOES sound very good :sad:

Damn you :green:

K

 

[Purusha]

Let's do the SUB as well :green:

8channels of 3 band :thumb:

 

[khstudio]

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[khstudio]

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[clintrubber]

[quote author="khstudio"]
I may start breadboarding just the "air" band tonite.

QUESTION:
I mentioned a few times that the circuit is parallel = 1 is the raw signal & the other EQ - the EQ pots are summed using 5.62k resistors (6 TOTAL) If I ONLY build just the "AIR" band I won't need all the summing resistors :? BUT, won't that change the impedence :?: And how should I compensate or do I even need to :?: :?: :?:

Thanks,
Kevin[/quote]

I'm not familiar with the exact functionality of this unit (a pic of the frontpanel would be nice, couldn't find a decent one).
But let's try: OK, so there's one 'dry' path to an output-summer and several parallel paths doing a certain frequency band ? If you only want one then no corrections needed I'd say. Since this is a pile of opamps doing filtering & summing all will be 'independent' I assume.
So just try it, I expect it'll just work.

Nice work !

Bye,

Peter

 

[khstudio]

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[Greg]

Nice work khstudio. I'm gonna take look over this the next few days.

One thing I noticed, and it's very, very minor. It looks like you used the resistor symbol for the inductors L1 and L2. Look for a symbol that looks like a coil... looks like the primary or secondary side of a transformer symbol.

:guinness:

 

[clintrubber]

Thanks for posting this :thumb:

Is the sum-collection-point at the top-side of R31 (@U5) ? Label might be missing.
edit: no wait, I see 'EQ-sum'. But what's U5 doing ?

Cheers,

Peter

 

[peterc]

Kevin

Check your email, I've updated a lot of the parts & the schematic.

I think U5 should be an inverting amp.

Peter

 

[khstudio]

I'm in a session right now after getting about 4 hours sleep :sad:

Please post all the questions you want & I'll be back in a few hours.

I am aware that some corrections are needed.

Greg, I'll fix the inductor :thumb:

 

[nielsk]

This is a great EQ, it's the poor mans GML. Leaving out the other bands would be a mistake! Please see it through and do a full unit, I have wanted one of these for a long time and would love to be able to build myself one.

 

[okgb]

Massenburg had said i believe that he put his bands in paralell
becuase it sounded better although it limited the max boost
I have a schemo someone had made without the servos

Nice work KH

 

[peterc]

Here is an updated version with my idea of U5 - I'm open to correction....

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Changed some of the resistor values to match those on the PCB.

The stranges thing I can't figure out is the 2.5k on the high shelf & the switchable one don't seem to be using the same cap values...check it out please... but it is right.

I think they have done this to get different Q's.

I've simulated the values & they seem good for the bell bands, never sure of where the effective freq is for a shelf. The shelf EQ's are in the right ballpark though.

 

[khstudio]

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[khstudio]

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