Neumann W492 equalizer DIY project (PCB docs added)

[audiophreak]

.... what I do...fart  ;D

  after spending a little more time with these I like how they sound especially the upper mid section and am going to install a bigger PT. It seems to be working fine but want the rails closer to specs.

  Thanks again to audiox and everyone who contributed, without this forum and the people in it I would not have found this wonderful hobby

btw  -  envelope - how are you doing with this project ?

 

[audiophreak]

  Thanks !
              I'm glad you like the knobs, and that's awesome customer service, I'm happy it all worked out for you ( I'll bet it took a little bit of the " Sting " from those Sfernice P11A's )  sounds like you have a good proses.

  Keep us informed of your progress and parts selections. 

 

[JBVries]

Can someone tell me what kind of power these thugs take and a potential adequate PSU as I can't seem to find that info anywhere and my 492s are pretty much finished. Cheers and thanks in advance.

-JB

 

[audiophreak]

  envelope - That looks awesome !  is the case painted or powder coated ?  I like the contrast with the dark case, brushed aluminum Dans panels, black knobs with white caps. very cool     and of course the N.. badge     ...  any inside pix ?

 JBVries - I used part # 70053 - from Digikey, its 500mA  CT secondaries in series for 4 units and I think I pushed it to the limit, am going to replace it with a #70063 that is 842mA in the same config. , but the 70053 should be fine for 2 units , although I dont know if it will fit in a 1U case or not .

  EDIT - the #62053 will fit in a 1U case, I'm using this one for a quad of SSL9K's - hope this helps

 

[mikefatom]

Stuart, that's a beauty! Really nice wiring work and layout!

Are those 0.1% vishay resistors throughout that I see?

Sweet!  8)

edit: nevermind, I just saw your post mentioning the 1% Dale resistors.

 

[audiophreak]

Stuart, that's a beauty! Really nice wiring work and layout!


Sweet!  8)

  X2 ...  Thats some beautiful work !  gotta figure out how to get my wiring that nice  ;D

btw ,  what opamps  did you end up using ?

 

[audiophreak]

Ha Ha !!  I'll have to try that  ;D

  What models of Analog Design OpAmps are compatible ? if they're not too expensive I wouldn't mind getting a set and A/B with one of the other channels.

  On another note, I got a hold of a signal generator and went to calibrate the  W492s. I found that the trimmers had very little effect on the level - like only 1.5db . but they were all very close and was able to get them +- 0.5db -  were yours similar ?

I perf boarded a tube heater supply for a G9, and got the legs on the trimmer wrong and experienced a similar result, but wouldn't  the pin config on the PCB prohibit that ?

 

[audiophreak]

are these the ones ?

http://www.newark.com/analog-devices/op275gpz/ic-audio-op-amp-9mhz-dip-8/dp/19M1029

 

[drummerjoe31761]

I have a complete Behringer P/S from one of their tube comps? I vandalized, Do you think I could adapt it for this project, I've looked for the Schemo's but haven't found the yet
Thanks
Joe

 

[adrian]

i built 14 of these eq for a project and i like them very much!!! thank you audiox!
I 'd like to add a variable HPF to these (maybe 2 positions 100hz and 180 hz), so i'm looking for a good schematic!
i looked on the forum and on the internet but i don't know how i could add something like that to these eq, do i need a symetrical HPF schematic or could i take an asymmetrical signal somewhere in the signal path, send it to the hpf and then re-send it to the eq?

 

[Morelius21]

Hi people,

I want make 2 eq but I have a question. In Gustav set is incluided de psu pbc? or  I must make mine?  can you tell me where to look the informantion?
I'm new and I'm still learning to move around here 

Thanks 
Morelius

 

[adrian]

as i know gustav doesn't sell power supply with these project,
but you can find some very good power supply on jlm audio website,

i think you could also use the ssl9K power supply,

 

[deneme]

Potentiometers should be? Single or double?
What characteristics could you help what should I take?


I use it?

 

[3nity]

read the first pages of this thread.

 

[JBVries]

Finally finished mine. Love it!!!

 

[3nity]

Im in the process of racking mine too.
The only problem im encountering its nice and affordable knobs for the Omeg pots.
Shaft diameter is 4mm.

yes they sound great too.

 

[JBVries]

Im in the process of racking mine too.
The only problem im encountering its nice and affordable knobs for the Omeg pots.
Shaft diameter is 4mm.

yes they sound great too.

I found these based on my EQN build......

Go to digikey and type in Kilo in the search. Then select 3.18mm shaft. If they will work on the 4mm Sfernice pots on the EQN I don't see why they wouldn't work here. Maybe not authentic but it's something to check out. Otherwise it'll be about $65 for a 4mm collet set with colored inserts from Canford. Cheers!

 

[zayance]

If they will work on the 4mm Sfernice pots on the EQN I don't see why they wouldn't work here

The Sfernice type knobs that Peter proposed for the EQN have 3.18mm Shaft not 4mm, but maybe it fitted yours nicely? I'd like to know, because could make the pots turn not very centered...
http://uk.farnell.com/vishay-sfernice/prv6saabjyb25103ka/potentiometer-10k/dp/8795711?Ntt=8795711

 

[JBVries]

Yeah I might have to redact that. I have not tried this and thought that the shafts might be similar enough for this. My mistake.

 

[marcfrom]

I have build 3 W492 units, with SSL9k PSU.
When the machines are cold and i turn on i have no signal out(audio), the +15V is missing (on the PSU). I have to  turn off and on, and the +15V come and everything work ok.

I tried to deconnect the W492 PCB, and the +15V on the PSU board is ok, no need to turn off and on. It same on 3 unit.
My transformer is 25VA, my EQ with true bypass consume less than 200mA, so it's more than enough

Does anyone had the same problems?  :-[