Neumann W492 equalizer DIY project (PCB docs added)

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On the trafo/fuse note.. The 5532 docs say 8-16mA per chip, x 8 = 64-128 mA per channel... SOOO, for two channels 128-256mA total?
If I use a 15V trafo, that would mean 15V*.256A= 3.84VA... If I use a PSU such as the SSL9K, and a trafo with dual secondaries, would I double this (3.84VA per secondary)? If so, less than 8VA max is needed, which means a 10VA should be plenty (assuming no LEDs)...

Is this right?

For a 10VA trafo doing 2x15V, would the proper fuse value be 10VA/15V or 10VA/30V?
Plus some extra "headroom" of course.

Thanks!
 
In case anyone is using the Omeg pots & Tats case with this project - It looks like the Omegs stand taller than the originally spec'd pots. They do not come close to lining up with the holes. I am going to try keeping the top row on the PCB and wire the bottom row off board. As as side note, bending the leads to get the double ganged Omeg pots to fit in the PCB is really easy - just be careful.

 
I'm wanting to run this eq un-bal.  Will just runnung the + rail only work or do I just need to tap into pin 1 of U1a and not populate R1-4 and C 1 and 2?  Also how do I come out un-bal as well?  Should I just take the + out and call it a day?

-Casey
 
Unbalanced operation:

Input to the (-) pin. Change R1 to 10 kohm. Do not connect/ground the (+) pin.

Output from the (-) pin. Do not connect/ground the (+) pin.
 
audiox said:
Unbalanced operation:

Input to the (-) pin. Change R1 to 10 kohm. Do not connect/ground the (+) pin.

Output from the (-) pin. Do not connect/ground the (+) pin.

Thanks for that.

-Casey
 
are the boards gustav offers spaced for sfernice or omeg? just ordered some boards, need to get going on the pots.

thanks.

EDIT: i'm guessing by the timeline of the discussion that gustavs boards are the original with the 5.08 spacing. the 7.5mm board gerbers seem to have been posted later on. but, please correct me if i am wrong.
 
hello everybody, i've question perhaps stupid.

I've built 2 unit of dual w492 work fine but when use this  units i lose 6db .
i use a psu 2x15v 15va
And don't don't what about this lost .
Someone could give me help please.

 
if these are wired up balanced, will they still work ok if pin 3 is tied to ground? i have a mix of unbalanced and balanced gear i will be using mine with both. i have my patchbay setup so it shorts pin 3 to ground for unbalanced ins/outs.
 
are the boards gustav offers spaced for sfernice or omeg? just ordered some boards, need to get going on the pots.

Funny you mention that - I e-mailed Gustav the exact same question only yesterday, but his reply was that he honestly doesn't know.

I would guess they are the original boards for Vishay-Sfernice pots, but apparently the Omegs fit with a little pin bending.
 
i actually just grabbed those 5 sets. i needed 8 sets, was worried that TAW wouldnt have them.

laura said she could help me out, and had all i needed in stock. excellent. have a 4 space chassis on the way from RP Electronics to go with it. i'm psyched.

moral of the story is: laura is great, everyone should deal with her.
 
Days ago that I'm thinking of adding an high pass filter to the equalizer, with selection of three different cuts. To what extent might this be interesting? Any idea which would be the best way to add this feature to this project? What do you think?
 
I have the schematic for the Neumann HT75 HPF/LPF. It would appropriate. They are two channel ganged units and use 6 pole 5 position switches for frequency select and soft bypass.
 

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