Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #820 on: September 11, 2020, 01:40:52 PM »
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.


Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #821 on: September 11, 2020, 01:41:43 PM »
Noise

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #822 on: September 11, 2020, 01:42:41 PM »
Distortion

mikeyB

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #823 on: September 30, 2020, 04:28:59 PM »
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. :)
making better music!

TwentyTrees

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #824 on: October 01, 2020, 02:16:38 AM »
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. :)

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #825 on: October 06, 2020, 11:58:38 AM »
Here is a picture of my modules build in the meterbrige of my Studer 928

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #826 on: December 08, 2020, 12:14:44 PM »
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.
« Last Edit: December 08, 2020, 04:02:24 PM by lars on »

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #827 on: December 09, 2020, 10:17:30 AM »
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

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #828 on: January 07, 2021, 09:05:02 PM »
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

Re: Neumann W492 equalizer DIY project (PCB docs added)
« Reply #829 on: January 08, 2021, 02:15:52 AM »
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


 

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