Neumann W492 equalizer DIY project (PCB docs added)

[kroeger1991]

I like the results with the OPA1656. I use them with a adapterboard to PDIP. A really nice, transparent and useful EQ. I will look if I find some NE5532s later and try to compare them a bit.
You are right with the decoupling, I needed to add a ceramic between one of the power rails and ground to stop receiving radio.  Others than that, since i don't have an audio analyzer here, I can provide some screenshots of the EQ inserted in my Antelope Orion HD gen3.

 

[kroeger1991]

Noise

 

[kroeger1991]

Distortion

 

[mikeyB]

My internet is a bit lumpy at the mo so forgive me if this has already been covered.......

It was mentioned a while back if the shelving bands could be switched to peaking bands.
Is this possible or a complicated process? I can't quite get my head around it?!?

Thanks in advance.

 

[TwentyTrees]

Hi Mikey,

It's theoretically possible, as the EQ stages are all state variable filters, but I can't see how you'd do it in practice with the PCB laid out for the W492 circuit.

The schematic breaks everything down and shows the circuit by band. The peaking sections (2 & 3) use one additional op amp stage compared to the shelves (1 & 4), disregarding input and output stages, so it would be pretty hard to mod the W492 PCB to make the shelves switchable to peaks as you'd need to pop an extra op amp somewhere.

It might be possible by hacking two PCBs together per channel and using multi-gang pots... That would probably qualify as a complicated process!

My internet is a bit lumpy at the mo so forgive me if this has already been covered.......

It was mentioned a while back if the shelving bands could be switched to peaking bands.
Is this possible or a complicated process? I can't quite get my head around it?!?

Thanks in advance.

 

[kroeger1991]

Here is a picture of my modules build in the meterbrige of my Studer 928

 

[lars on]

Hi every one,

Very nice to see these last builds !

I have some trouble with bypassing.
I tryed the relay "true" bypass and the mecanical switch bypass but
for both I have a drop of 3,8 dBu (from 0,775V to 0,280 V) when the signal goes from in to out.

Have you seen something like that ?

Thank's for any clue.

 

[lars on]

I found it !

When bypassing, we need to switch the input AND the output simultaneously.

So with relays, we need 2 for one channel and with switch we need one 4PDT.

 

[phetus]

Does anyone have Gerbers of this? Some friends and I would like to build a bunch, I need to order some PCBs for some other projects too so thought I'd just chuck them in there with the rest. Also, if i get on with them I'd be tempted to make a hole bank of them. Just to be clear: I have no intention of distributing or sell them.

Thanks

 

[TwentyTrees]

I don't think Gerber's have been made public, as these are available from Gustav at:

https://www.pcbgrinder.com/produktside/neumann-w492

Does anyone have Gerbers of this? Some friends and I would like to build a bunch, I need to order some PCBs for some other projects too so thought I'd just chuck them in there with the rest. Also, if i get on with them I'd be tempted to make a hole bank of them. Just to be clear: I have no intention of distributing or sell them.

Thanks

 

[pstcho]

Hello guys, ive build a couple of EQ and they are fantastic, but i see that i would like to ad a make up volume control

is there any nice way to do that with a potentiometer without destroying quality of the eq?

 

[JMan]

Does anyone have a suggestion for where to get the pots for this? AML hasn't had them in stock for a long time now and Colin isn't responding to "when will ____ be back in stock" emails these days. In my case, I purchased a 2U case and front panel from Frank, which appears to not be spaced quite right for PC-mounted pots on this board, so I don't necessarily need something with the correct footprint since it looks like I'll have to run wires anyway.

 

[Gustav]

Does anyone have a suggestion for where to get the pots for this? AML hasn't had them in stock for a long time now and Colin isn't responding to "when will ____ be back in stock" emails these days. In my case, I purchased a 2U case and front panel from Frank, which appears to not be spaced quite right for PC-mounted pots on this board, so I don't necessarily need something with the correct footprint since it looks like I'll have to run wires anyway.

I posted about some offerings from BE x amount of pages back. Search the thread!

Gustav

 

[JMan]

I posted about some offerings from BE x amount of pages back. Search the thread!

Gustav

Thanks! Thought I had searched pretty well, but missed your post I guess. All apologies.

Huh, there are actually a number of posts that completely got past me. Big face palm from me. I appear to have skipped a series of several pages as I read through.

 

[zero23]

Does anyone have a suggestion for where to get the pots for this? AML hasn't had them in stock for a long time now and Colin isn't responding to "when will ____ be back in stock" emails these days. In my case, I purchased a 2U case and front panel from Frank, which appears to not be spaced quite right for PC-mounted pots on this board, so I don't necessarily need something with the correct footprint since it looks like I'll have to run wires anyway.

Hey, I used the omeg eco pots, I used them 'on board' and frank, for a small fee, adjusted the hole positions according to the pot data sheet, the rear pins on the dual pots needed tweaking to fit the pcb, I know this dosent help a ton as you already bought the front panel, but they work well and are fairly easy to get hold of, it also saved a lot of wiring....

 

[frejo89]

Hey @ All: I have a little problem, where maybe somebody of you will be able to help me with?
I built the pcb exactly as the "project docs" said at creative-clowns.com.

I have the following problem: With low and high shelve everything ist alright. But to control the both Mid-Bands I have to turn both pots for dB and frequency in counter-clockwise. I have literally no idea, what the problem could be and i spend hours of searching for a mistake, but I can not find one -.-

I build 2 pcbs of it, both with the same issue - so the mistake must be made in the project docs?
I have no idea and Iam very desperate right now.

Is there anybody having this issue too or some idea, what would help? Should I change the pots Positions?

Thanks in advance,

jonas

 

[frejo89]

no ideas ?

 

[rock soderstrom]

no ideas ?

Wrong pots? Creative clowns link to these pots, yours look different.

 

[mukole]

Its been a while since i built mine so i might be wrong but i think maybe you have your pots mounted to the wrong side of the circuit board

Edit - Forget that, i just checked my build and yours look to be oriented correctly.

 

[frejo89]

Wrong pots? Creative clowns link to these pots, yours look different.

Yeah. Thought the same - but I made shure, that they both are 10k linear pots. So there is really no difference at all, despite they Look different.

ps: mine are alpha b10k Dual pots.