mixer done...UPDATE: New pics, frontpanel + meterbridge done

[hotbaby]

very good job! That was a lot of work i think  i wish you fun using it now.

 

[crisotop]

So just stick two 10Ohm resistors between the rectifier on the psu board and the 12V regs on the main board and populate the couple of lytics for the 12V supply?

Thanks!
Christoph

 

[radiance]

So just stick two 10Ohm resistors between the rectifier on the psu board and the 12V regs on the main board and populate the couple of lytics for the 12V supply?

Thanks!
Christoph

Those 10R resistors are already on the main board...Just leave out the bridge rectefier, the two big 1000uF caps, both 15V regulators and the two 22uF caps...
You will have to insert some jumpers though...

 

[Bogart]

Very nice work!
I can see you've got a SSL style with your builds 
I assume you used the (hard to find) EAO series 01 pushbuttons, where did you get them from? Did you replace the LED to get a different color?

 

[radiance]

Thanks Bogart!

I've those EAO's out of an old Neumann switch box. I just use the lamps that came with them. I did order some new ones from RS though. The next time the front panel comes off I'll replace all of them, just in case....

 

[maxwall]

Would be great to see a project like this turned into a DIY black market offering any one could build with option for transformer coupled and transformerless as a option with a high quality signal path that rivals the big $$$ console boards (modular in design).

 

[radiance]

Would be great to see a project like this turned into a DIY black market offering any one could build with option for transformer coupled and transformerless as a option with a high quality signal path that rivals the big $$$ console boards (modular in design).

I thought about that....but my version turned out very specific. Everyone wants other options and to include them all would be too much of a design task.
However, if there's enough interest I will make an effort to redesign the pcb of my mixer, make it more simple. Along the way I've learned a couple of things that I probably would have done different when I had known them before.

For example,

1) I would leave out the dual mono vs. stereo option on the stereo input channels. This will lower the already very low bus noise since this option add's bus noise of another 20 channels where as stereo only has 10 channels per summing amp.
Instead make 2 mono channels or  so...It also saves you 3 DOA,s and 30  relays and some other bits and pieces...

2) I would try to make the whole project on 1 pcb, well..at least all audio on one pcb. This means no unbalanced connections inside the box.

3) leave out the swap option of the insert order. This was very hard to do without logic switching and did add a lot of relays...

any comments are welcome btw...

 

[crisotop]

3) leave out the swap option of the insert order. This was very hard to do without logic switching and did add a lot of relays...

But this would be the key feature for me, besides a dedicated M/S Processing insert.

christoph

 

[radiance]

3) leave out the swap option of the insert order. This was very hard to do without logic switching and did add a lot of relays...

But this would be the key feature for me, besides a dedicated M/S Processing insert.

christoph

The ability to route groups to each other gives you a swap option. For example:

Channel > group1 > group2 > master bus
Channel > group2 > group1 > master bus

As it is now, you can also swap the order of both insert slots on groups 1 and 2 and on the master.
Endless possibilities but a bit too much if you ask me.... but if necessary, that swap option can stay 

 

[audiovisceral]

Would be great to see a project like this turned into a DIY black market offering

I thought about that....but my version turned out very specific. Everyone wants other options and to include them all would be too much of a design task.
However, if there's enough interest I will make an effort to redesign the pcb of my mixer, make it more simple. Along the way I've learned a couple of things that I probably would have done different when I had known them before.

For example,

1) I would leave out the dual mono vs. stereo option on the stereo input channels. This will lower the already very low bus noise since this option add's bus noise of another 20 channels where as stereo only has 10 channels per summing amp.
Instead make 2 mono channels or  so...It also saves you 3 DOA,s and 30  relays and some other bits and pieces...

Ah but this would be such a key feature imo! The stereo/mono select is what makes these guys like the dangerous 2-bus and folcrum versatile.  Plus 125dB noisefloor is fantastic enough already, by any standard.

If you ever get fabio/gustav/etc to do a pcb run and sell them I'd love to make one. The only change I'd make is to only have 1 (instead of 2) send groups/inserts. Bu I would be perfectly happy with it as is.

Amazing build. All those 990s must sound great! Are you happy with the sound vs. something like the dangerous unit?

Cheers.

 

[radiance]

Ah but this would be such a key feature imo! The stereo/mono select is what makes these guys like the dangerous 2-bus and folcrum versatile.  Plus 125dB noisefloor is fantastic enough already, by any standard.

Sorry, I was not very clear on the reason to ditch the mono stereo option. The main reason is that it makes the build almost twice as complicated. Channels set to dual mono are summed by their own mono summing bus. That signal is split and routed to both left and right bus. True, it makes the unit very versatile, but in real live I only use two stereo channels in dual mono mode. I might design the pcb so you can choose which and how many channels will be mono or stereo. This will be done by means of hardwireing them instead of making it switchable. It will save you about 30 relays, 3 990 doa's, 9 604opa's and a lot of pcb real estate

If you ever get fabio/gustav/etc to do a pcb run and sell them I'd love to make one. The only change I'd make is to only have 1 (instead of 2) send groups/inserts. Bu I would be perfectly happy with it as is.

This might be a key feature for other people. Espacially when you considder this more as a mastering tool.

Amazing build. All those 990s must sound great! Are you happy with the sound vs. something like the dangerous unit?

Cheers.

Thanks. It sounds very clean with loads of headroom. I have not compared it to other units though....don't bother really.

 

[audiovisceral]

Sorry, I was not very clear on the reason to ditch the mono stereo option. The main reason is that it makes the build almost twice as complicated. Channels set to dual mono are summed by their own mono summing bus. That signal is split and routed to both left and right bus. True, it makes the unit very versatile, but in real live I only use two stereo channels in dual mono mode. I might design the pcb so you can choose which and how many channels will be mono or stereo. This will be done by means of hardwireing them instead of making it switchable. It will save you about 30 relays, 3 990 doa's, 9 604opa's and a lot of pcb real estate

That's too bad - I really hope you can find a way to keep the switching as an option. I need it as I would be using the unit for a variety of mixing/summing/bussing purposes, all of which would need different and flexible configurations.

Would it be possible to include the mono/stereo switching section on the pcb, but make it easily bypassable via jumpers or hardwire cables?

That might give the most choice for everyone. It would be awesome if so.

 

[radiance]

Would it be possible to include the mono/stereo switching section on the pcb, but make it easily bypassable via jumpers or hardwire cables?

That's already possible. It's just that I want to make this whole project more "clean/neat" ...less wiring.
The wiring was the part that gave me the most headache...

Let me think about it. I have to say, I really enjoy pcb design...it just takes an awe full lot of time.

 

[Bogart]

Very nice work!
I can see you've got a SSL style with your builds 
I assume you used the (hard to find) EAO series 01 pushbuttons, where did you get them from? Did you replace the LED to get a different color?

By any chance, do you know the voltage of your lamps? I found some EAO switches for my SSL project, however there are different types: 12V, 24V, 28V, 36V. I assume I would need 12V but it's worth checking, thanks!

 

[radiance]

I've used 24V ones. They run on something like 19V though...not as bright but longer life..




"not as bright but longer life" sounds like an add for  ECO friendly washing powder . .  .    .

 

[Bogart]

I've used 24V ones. They run on something like 19V though...not as bright but longer life..




"not as bright but longer life" sounds like an add for  ECO friendly washing powder . .  .    .

Ok thanks! Where do you get the power from ? I'm scratching my head with the way I can connect them.
As the pcbs drive a 15V tension, do you think I could get 12V lamps and then just add a resistor in between?
I will use 3 push-buttons (like you did) which will need to be powered up. I will also install the supersidechain board which has a led connection already fitted. Could I hook them up in parallel or should I find another solution? Cheers,

 

[radiance]

do you think I could get 12V lamps and then just add a resistor in between?

Yes, add a resistor to drop the voltage to whatever you need (ohms law).
It might be a good idea to make a separate (off board)  PSU with LM317 /337 regulators. This way there's less chance you'll get hum.

Could I hook them up in parallel or should I find another solution? Cheers,

Sorry, don't get your question....

 

[Bogart]

do you think I could get 12V lamps and then just add a resistor in between?

Yes, add a resistor to drop the voltage to whatever you need (ohms law).
It might be a good idea to make a separate (off board)  PSU with LM317 /337 regulators. This way there's less chance you'll get hum.

Could I hook them up in parallel or should I find another solution? Cheers,

Sorry, don't get your question....

One last question (at least for now ), on the first and second clone you built, can you confirm you used single pole EAO switches?

 

[sahib]

I realise that this issue has been addressed and answered but I still think that those components through the aluminium heatsink on the psu is not a good design practice without any insulation around them. You should either have shrink tube on the components or plastic washers inserted into the holes.

Other than that, congratulations.

 

[radiance]

One last question (at least for now ), on the first and second clone you built, can you confirm you used single pole EAO switches?

No, I used dual pole  switches but I think it can be done with a single pole as well...

...... I still think that those components through the aluminium heatsink on the psu is not a good design practice without any insulation around them.

You're probably right...but in this case the heatsink gets only mildly warm, not hot at all. I could even remove it without the regulator getting overheated I guess. Trust me...that heatsink nor the components are going to move by themself...there is at least 2mm spacing between the components, jumpers etc. and the heatsink.