Neumann W492 equalizer DIY project (PCB docs added)

[mitsos]

Just a passing thought:

Has anyone looked into ordering a bunch of custom dual concentric pots from Omeg for this build? I was going to send in a quote request, but I feel silly doing that knowing there's no chance of me buying them. If they could be made for like 10-12 bucks a piece would that be worth it to anyone? That might make this project 51x-able?

http://omeg.com/p2c2bub2.htm

Why not buy the ones that Colin is stocking at audiomaintenace?

Simply because I didn't know he sold them... :-[

I don't think he does. He does sell the Vishay Sfernice pots that were the ones Audiox originally designed this board around, but they are individual pots. You want dual concentric to be able to do freq/gain on one pot, right?  That'd be pretty cool, but you'd need a couple of 3-gang pots and two duals. If you got them made, and this board fits in the space of a 500 module (I don't have dimensions in front of me), you'd just need one of those mini 500 adapter boards like geoff in this post (where do you get those anyway?):
http://www.groupdiy.com/index.php?topic=11320.msg414991#msg414991

 

[[email protected]]

where can i get the board for this eq? the link that saids it, saids its invalid.
anything? thanks.

 

[[email protected]]

where can i get the board for this project?

 

[mitsos]

gustav sells them in the white market.

 

[Deyo]

Sorry to bother but I just finished the 492 units and they are hitting me with 12 DB extra . Anyone have any ideas ?  thanks  D

 

[stereokillah]

Pehaps balance , unbalanced

 

[audiox]

Sorry to bother but I just finished the 492 units and they are hitting me with 12 DB extra . Anyone have any ideas ?   thanks   D

Do you mean that the overall gain is 12dB when all filter switches are off? In that case there must be some mistake in your component assembly. A wrong value resistor most likely. If you have a level meter, troubleshooting is easy. Feed 1kHz sine to the balanced input. The level at the output of the following op-amps should be 6dB lower than at the balanced input: U1A, U1B, U3B, U5B, U7B and U7A. If not, you have located the fault.

If the overall gain is ok but some of the filters boosts or cuts too much, try to adjust the trimmers. There are instructions how to do that. If it doesn't help, check the component values.

Pehaps balance , unbalanced

12dB of extra gain is too much to be caused by that.

 

[stereokillah]

yes should be 6 bd sorry but i don't know wich db does he talking, and i had this problem with my first w492 i used unbalanced plug.

 

[Deyo]

Audiox,
  Yes it is 12 DB over when all is shut off.  I will do what you said to do today. I will leave the result later tonight.  Thank you for the help  D

 

[Deyo]

Well no chance today. I will try to get back to it on Fri. Not enough time in the day.

 

[benlindell]

Hey man, just finished my first one today and got a chance to bench test it. Everything worked right away, which is nice for a change. This thing has insane amounts of gain, everything feel really nice, it's crazy how much you can cut and boost with this. The lowend extension goes all the way down too. I'm looking forward to finishing my other ones up and getting these in the rack.

Thanks for all your work.

 

[Moses]

Hey, I've just finished building 2 channels of these with Sfernice knobs, and am trying to fit them into Perusha boxes. Im a little stuck though, because tat includes a false from to mount the knobs on, which I did. However, the shafts aren't long enough to reach through the front panel and the holes aren't big enough to just mount the pots on the front panel.

Has anyone else had this problem, or got a solution?

Thanks,

Mo

 

[MartyMart]

Hey, I've just finished building 2 channels of these with Sfernice knobs, and am trying to fit them into Perusha boxes. Im a little stuck though, because tat includes a false from to mount the knobs on, which I did. However, the shafts aren't long enough to reach through the front panel and the holes aren't big enough to just mount the pots on the front panel.

Has anyone else had this problem, or got a solution?

Thanks,

Mo

I have the same problem, sfernice pots were too short so I sold 'em and got a set from Laura @ TAW
These DON'T fit the boards/ case like the sfernice though so you have to wire them "off board"

Perhaps the better option is to get longer spindle version of the sfernice ! but at £8 a pop this was too
rich for me

MM/

 

[ahstarr]

Marty check this:

http://www.audiomaintenance.com/acatalog/potentiometers_conductive_plastic.html
SF-01-009 - 11mm - 2 gang 10k linear

I can only see the SF-01-007??????

 

[audiox]

Has anyone else had this problem, or got a solution?

I have never seen that enclosure and I know practically nothing about its construction. I hope that someone else in this forum is able to help you. I guess Purusha forgot that Sfernice potentiometers are available in variety of shaft lengths. Those sold by catalogue distributors are usually with long shaft and the ones meant for mixing console spare parts have shortest possible shaft.

I can only see the SF-01-007

Maybe Colin has discontinued the 2x10kLIN without center detent. It was available when I made the layout...

EDIT: If he is reading this, maybe he could tell us if it is just temporarily unavailable or permanantly discontinued.

 

[iangomes]

the SF-01-009 were there yesterday... looks like i got one of the last (if not the last) set.

 

[ahstarr]

the SF-01-009 were there yesterday... looks like i got one of the last (if not the last) set.

apparently they will be back in the store (depending on demands) in 14 weeks....

Does anyone know other places to get these???

/andreas

 

[sirzodiac]

Hey, I've just finished building 2 channels of these with Sfernice knobs, and am trying to fit them into Perusha boxes. Im a little stuck though, because tat includes a false from to mount the knobs on, which I did. However, the shafts aren't long enough to reach through the front panel and the holes aren't big enough to just mount the pots on the front panel.

Has anyone else had this problem, or got a solution?

Thanks,

Mo

hey folks,

just finished a dual channel with purusha's case and the vishay sfernice pots reference marty mart posted earlier and i did as well in another post.
everything works fine, the pots DO fit the board and the shaft DOES fit perfect for purusha's cases.
what probably should be said is that the shafts are not going through the front panel, the pots are mounted on the mounting plate and the plate is mounted with a fixed distance (through the L-bendings on each side) to the front panel, so only the axes are passing the holes. as the axes are 4mm a 4.5 or 5mm hole does the job.

and it looks great, and it SOUNDS great, YAW!!!

good luck everybody,
b.

 

[outoftune]

has anyone built the w492 with a purusha case and the green omeg pots? will this work if they are not mounted on the PCB and are hardwired?

 

[buschfsu]

i have the purusha case and the green omegs.  ill be building this month and let you know.