Neumann W492 equalizer DIY project (PCB docs added)

[mitsos]

If anyone is looking for alternate pots for this project, Laura at TAW has offered to order the Omeg ECO pots. 10K linear singles and duals. I placed a feeler in the BM to get some idea of quantities so she does not get stuck with a bunch of pots, and we're looking at about 50 channels... I think the pricing will be about $18 per channel..

The only caveat is that the duals have 7.5mm spacing between the two rows of leads and the pcb is 5mm, but it's not a problem for me.

Check the feeler for more info. This is not a group buy, the pots will be sold by TAW.

 

[kazper]

I checked out the omeg's that I have left over from my Calrec purchase and they will fit nicely provided you don't buy real boxy caps. As Mitsos said, there well be some bendage to get the duals in there.

Cool if this goes through as I need some caps from TAW and been holding out.

Kaz

 

[RedNoise]

Hi there , sorry for the noob request , but has someone done a bom??I'm working on mine , and , as always...I'm lost in the forest of ceramic / film capacitors...
Thx...

 

[mitsos]

I could send you mine.. but there are no part numbers.. Just a bit more info than audiox's part list (lead spacing etc). Don't know if it will help you much, I just send it to Laura at TAW with a request for polypro caps where possible, and she sent the stuff to me. Except the pots/trimmers/swtches/ICs. pm me your email if you want me to send it to you.

 

[cannikin]

you can try this, part numbers are from Mouser:

you can handle the resistors - metal film mouser #
271-THE_VALUE_OF_THE_RESISTOR-RC Example (271-1K-RC = 1K)

This is where I'm going with it but use at your own risk....

 

[RedNoise]

Ok Mitsos , thx!!!
With F*rnell , I've several problem to find all poly in the w*ma brand...

Here is mine :
http://www.keepandshare.com/doc/view.php?id=798030&da=y

EDIT: thx Cannikin too!! :thumb:

 

[RedNoise]

It's easier for me to have all from F*rnell , but if every poly (wima) are avaible at TAW , I'll order them here...
what about CK7101??No suitable parts at F*rnell??
what about Phoenix resistors 0,6w??Good brand??
thx guys , really helpfull !!

 

[mitsos]

the CK7101 is the switch? I think any switch will work, no? Someone pls verify this?

.6W resistors seem like a lot..You may have issues with things not fitting the board. It's pretty tight. On the BOM I sent you I put the max width and/or length of the caps so I wouldn't get something too big. You may have cosmetic probs with two of these resistors next to each other, or next to a cap. Things may not fit flush... Cannikin's suggestion above brings up 1/4 W.

I ordered all 1/8 W resistors. I hope that's not too little? Audiox or anyone else care to comment?

 

[RedNoise]

In fact , I do not find a CK7101 at F*rnell...and I've no idea if it must be on/on or something else...We'll see!!
:green: :green:

 

[RedNoise]

regarding .6W resistors , I've tried with some I'd laying around .It s ok.
What about the brand??Is it a good brand??

 

[buschfsu]

cannikin, your bom has polyesters and ceramics mixed in. i though polypropelyne/styrene was the best way to go for eq? any concerns with these?

 

[bernbrue]

Hi,
I thought of using Lorlins (1x12 and 2x6) instead of the pots. Ok, I would have to wire them, but are there any other obstacles I didn´t think of?

My questions:
- would it make sense to use switches instead of pots (was thinking of using it as mastering EQ)
- are the most relevant frequency covered with Lorlins?
- are 12 positions (6 for the dual pot) enough for mastering purpose?

Would like to hear your suggestions/opinions
regards
Bernd

 

[craptical]

Hi Bernbrue!

From a mastering perspective I would feel a bit limited with so few(6) frequencies in the midrange. I would go pots for frq (Maybe even one set of frq controls for both channels, where possible (4-gang pots!)) and rotaries for amount, in +/- .5 dB steps. This gives you a range of +/- 3 dBs if you skip the "zero" position in the middle (and use the in/out switch). I rarely find myself going outside the +/- 2 dB range when mastering. Maybe a .5/1/1.5/2/3/4 scale could be useful if greater range is needed.

I was also thinking about this project as a possible mastering tool, so I too welcome any additional thoughts on the subject.

:guinness:

/Dave

 

[Gold]

I am building a couple of EQ's for mastering. I have these boards but I don't plan on building them anytime soon.

I'm using 12 position switches for gain and frequency. Gain is +/- .5/1/1.5/2/3.
I think having more choices for frequency is good. It's more important to work in the right place. I wouldn't use pots unless the the frequency range was small. I like good left/right channel matching.

 

[craptical]

Thanks Gold, good point about channel matching. And also, repeatability gets lost with pots.

 

[bluezplaya]

How do these EQ's sound?

 

[cannikin]

Anyone have a correct part number (US) for the trimmers. I bought a set from from Digikey and they are the wrong ones... hate when that happens

 

[RedNoise]

Hi Cannikin...
I bought those : 9607927 and 9607978 @ Farnell...(Vishay)
Hope that helps...
Cheers.

 

[cannikin]

Thanks RD

heres the mouser numbers for USA

594-63P103
594-63P201

 

[cannikin]

Ok I thought there was a post about this but I can't find it

Value of C10 and C8?

NEVERMIND.... They are not needed unless you want to change the Freq.

its in there