Finished! Sub-Group Summing & Monitoring

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ej_whyte

Well-known member
Joined
Nov 12, 2010
Messages
263
Location
Cambridge, UK
Well I have finally finished this project. It is my first design and is the main part of my dissertation that I am just starting to write.

The basic concept is 16 ch summing, with each stereo pair routable to a choice of two different gain stages. One stage is 990c + THAT 1646, whilst the other is 2520 + 2503. Each stage then has its own insert and level pot, before being summed for another master insert and then outputs & metering. The unit also includes a monitor controller, which can either be fed from the summing output, a front panel TRS external in, or a rear panel RCA external in.

There is a bit more background here: http://www.groupdiy.com/index.php?topic=48614.msg615834#msg615834

Thanks to not only the people that have answered any of my questions directly but everyone for all the background reading you have provided.

Even bigger thanks go to Tom Waterman for the guidance & inspiration, Jeff Steiger for all the great components, Sahib for helping with the machining & JLM for the PSU.

PCBs for 2 units

hydra01.png


hydra02.png


hydra03.png


hydra04.png


hydra05.png


hydra06.png


16 Ch THAT 1200 input board & external in/send&return board

hydra07.png


Bus routing board, bus vol board, insert/bypass board

hydra08.png


Main fader & headphone amp board, monitor section board

hydra09.png


Gain stages. Left pair is 990c, right pair is 2520

hydra10.png


hydra11.png


hydra12.png


JLM PSU

hydra13.png
 
Ha thanks for all the wows :) I just finished finished building it on friday so it isn't even fully tested yet, fingers crossed though. Ill put up the schemo when I have tidied it up and given the unit some better testing

Cheers
 
Oh wow! Commercial build throughout it seems. Heck, you even have an internal color scheme like some interior designer!  :eek:

Probably not the most practical decision to have all the wires same color from debugging point of view. Maybe you have good trust you never mis-route anything and always remember the routing inside out. But what about 15 years from now when it needs service...

Also, very thick PCB's, enough to survive a drop or two perhaps. Where did you have them made?
 
Kingston said:
Oh wow! Commercial build throughout it seems. Heck, you even have an internal color scheme like some interior designer!  :eek:

Probably not the most practical decision to have all the wires same color from debugging point of view. Maybe you have good trust you never mis-route anything and always remember the routing inside out. But what about 15 years from now when it needs service...

Also, very thick PCB's, enough to survive a drop or two perhaps. Where did you have them made?

Well it started because I wanted it to have a white front panel and green LEDs, and white PCBs just look the best, and then by coincidence the Nichicon B.P caps I wanted were green as well, so I thought why not make it all green & white! I have used the dark green for any kind of power related connections whilst the lighter green are signal. True its not the most practical but I have been working on this for about 18 months so I'm pretty sure where everything goes, and I buzzed it all out with a multi before powering it on. If I was building to sell I would do different colours, but I don't plan on selling this anytime soon.

The PCBs are 2mm, from PCBCart.com. It took a bit of explaining for them to understand the slots between boards so that they could be snapped, but other than that they have been great.

Regarding PCBs, I have had a couple of people ask me if i'm selling them already. The situation is that this is not fully tested yet, and the first thing I have designed entirely by myself, so there is a good chance that some of it will not be 100% yet. Once it is tested and I am happy with it then I may consider selling PCBs afterwards, thanks for the interest though :)

Cheers
 
That's a masterful piece.

About the most desirable  summing unit  I've ever seen.

Well done - what an amazingly high standard you set  :)
 
For anyone interested, I have finished writing my dissertation now and the final specs are shown below. The mixer has a 50Hz mains hum problem (-74dBu) at the minute but I haven't experimented with shielding yet. On my long list of things to do.

 

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