Discrete Mixer (reuploded fotos)

[joaquins]

Hi... I'm new around... I live in Argentina. Excuse my poor english.

I want to show you my current project and see your opinion... I'm building a modular discrete mixer, something like 16*08
In the first stage I'm going to build the mixer, but then it will have 2 51X slots per channel.

The Schems:

Input Amp:

Faders Buffer:

Summing Amp:

Out Amp:

The schem of the assign an pan board is missing, not a lot of sense show a board with lot of resistors and switch... I use single pot pan and 22K metal film mixing resistor


Some pics of the boards

The Summing amp board (no opamps)

25*20

DOA's

Pan & Asign

Components

My folder of resistors and stufs... a realy good thing and a big time saver...

Connector

Some SketchUps

Structure

Boards

Full

Waiting for your comments... If someone intrested, i can send all the eagle proyects with those schems and DOA's various.

JS

 

[gemini86]

None of your pictures are loading for me.

 

[gemini86]

Working now, thanks

 

[bruce0]

You might want to take a look at ClassicApi.Com they have a backplane that might easy your wiring load considerably.  Each one takes 8 51x modules, and there are some traces to allow relays to be mounted to the backplane I think that are for some routing function... not sure really , I have not seen a schematic.

He also has metalwork modulary aluminum bays that run flush against each other (don't know there is a gap between faceplates every 8 slots or not, but the back is open I think, so your "channel strips made of 51x modules approach" could work I think.  Check it out.

There is also the very fine GDIY 511 but that is 19 inch rackmount, and I don't think you can buy just backplanes.

 

[wolfgang]

Congrats!!
You have a really nice project out there! ( And a lot of work to do )

I would be interested in your DOA  eagle projects. Maybe you can post them or send them per mail f you don´t mind sharing them of course!!

regards, and lots of motivation for you!!!

Wolfgang

 

[joaquins]

yeah.. a lot, but working on...

don't matter at all... working MOD-1 and 25*20 projects: (check tansistors pinout, think miss something in eagle)

http://www.mediafire.com/?f7vg1qbjp6tb7nt
http://www.mediafire.com/?obja17varugjuj5

25*10 (not tested)
http://www.mediafire.com/?pu2dd55xdjfvud2

JS

 

[coriolis]

Hey joaquins - looks really good! I've got (long term) plans for something similar, so I'll be watching your progress too. Good luck with it!

 

[wolfgang]

Thanks for the files!
Will have a look the next days!

I can imagine how much work you have to to do! I build a small console this year for a project and it was only 8 Inputs with only mute/solo Pan and a Fader and it was really much time i needed. Building the frame was also really time consuming! Do you build the whole thing by yourself or do you have some helping hands around you??

Here are some Pics from my little console :

http://www.wuala.com/wowo/public/MIX_ONE_PICS/

regards,
Wolfgang

 

[joaquins]

for the chasis and all heavy metal work i have a smith of trust, electronics all by myself... have sick last 4 month, get all the develop there and the DOA experimentation...

now I'm starting to build the boards and DOAs

Nice job... how does it sound? have you made some AB with yor favorit DAW?

JS

 

[joaquins]

IMPORTANT!!! For those discrete projects, check the transistors datahseet, i think i miss up something.. sorry, they are working, but with some transistors rotated 180º... SORRY

 

[wolfgang]

for the chasis and all heavy metal work i have a smith of trust, electronics all by myself... have sick last 4 month, get all the develop there and the DOA experimentation...

now I'm starting to build the boards and DOAs

Nice job... how does it sound? have you made some AB with yor favorit DAW?

good to have an smith of trust!!!! Building a frame is really a lot of work when your not a mechanical worker!
I had do develop and build my console in about 5 months as it was a project for a exame! ( And learn how to use eagle and etching) I have never ever worked that much in the last 2 months of the building process. 14 to 18 hours seven days a week. I am glad its finished now!!!!!!!!!!!
But i need to build another frame with 12 Inputs for Studio use, and aux system.......... but first i need some holidays.

Extensive tests in the Studio ( haven´t done critical AB- Test for now)  will follow but what i heard already I like the Sound of this little thing a lot.

One Question about your UREI-DOA: On the Board you have paralleled the Input transistors- for what reason? Input noise??
Will test your DOAS when i do the next etching.

As i am going through you thread once again i see you build your console complete discreet? Cool man!!
Wanted to do the same thing in the beginning but decided to go discreet only in the summing-module. Cost and Space..........

kind regards,
Wolfgang

 

[joaquins]

I keep the space for 3 input paralleled transistors because I have the space, so... it woudn't harm. today I build 2 MOD1 but with simple input opamps, so I build 4 25*20 and 8 cables for cotencting from the DAC. Last night i meter 100 transistor for Vbe and hFE...


Now with this i can try maybe tomorrow the summing stage... without bal input, fader buffers and output drivers, but have to put in orter the workshop first.


JS

 

[wolfgang]

Hello!

Any new progress about your build?? I am courios !

regards,
Wolfgang

 

[grantlack]

This is beautiful work! I just recently tested >500 transistors, so I feel your pain.
I like your method of organization, I've been trying to find similar pages but have yet to find any with flap closure. Can't wait to see more!

 

[tomas1808]

Wow awesome thread.

Wolfgang really love that little mixer! Very clean build. Would love to see a big brother  . BTW, are those panels made by Schaeffer?

Joaquin, I have been dreaming of doing something similar. At first I thought of making a huge MIDI controller (midibox) but I am getting more inclined in making a real console.
Good to have someone doing the same things you like nearby. I will surely ask some questions when I get to start the project.  :

What is currently keeping me back (apart from money ) is the presicion metal working. What are you going to do with the front panels? Are you going to buy standard 500 series panels from ClassicApi? Or are you going to get them custom made? The CNC cut panels I have seen so far are prohibitively expensive. They add up very quickly. Please let me know!

Suerte desde Uruguay!  ;D

 

[wolfgang]

Would love to see a big brother  . BTW, are those panels made by Schaeffer?

I want to see a big brother too!! Need more time and money............... My plan is to add one 12 Mono-Input Frame and four aux-sends to every mono input as well  as a rack with Stereo inputs (8 + 4 returns).  I have etched a test Version of the Stereo-In yesterday. But this takes time. Now my dayjob is more important!

Front panels are Laser-Cut by a friend and afterwards got the blue anodising. Engraving is missing until now but will come. or i just make some Marks for 0db and leaf it!

regards,
Wolfgang

 

[tomas1808]

Good to know you are still going with the project. Dont forget to upload pictures 8)

I guess I'll have to find some way to get the panels made for cheap. I think I'll have to DIY a CNC before doing anything else. A CNC would certainly speed up the process.

 

[wolfgang]

Yes a CNC would be nice to have!!
But it is not really cheap and i think you need a lot of time to get the results you want. In the meantime i can design electronic stuff that i am more after!!

The big problem are rectangular cutouts for faders. the rest you can easily drill by yourself. I build my Mixer in 19" format and i am thinking of using standart 19" Panels for the Aux sends. This will be much cheaper then single-modules.but also not so convinent in the building progress and maintanence.

But back to the original topic!!!!! Joaquins: how is it going on???

regards,
Wolfgang

 

[joaquins]

Sorry I've been absent... today i boght a couple of cores for trying to build some output transformers and a couple of OP27 (presission opamps) for the servo of summing amp, have a couple of trouble with the dc offset, cant take it below 100mA or so... awfull, so working on the servo, dont want to have caps in the signal path, here around doesent are good caps, so, better dont use them, and i cant bring some from other place, the costums are bad people... jaja

when have some transformer working show the results, have made one but the core isn't good, so, will try this winding with new core to see what happens...

ah... about the front pannels, planning to make them myself, maybe with a foot print and patience, i wont use faders, just rotary pots... dont like to see the mix, just listen, also dont use much vu meters... just my ears... of corse in the critical places, dont want to burn anything, but not a looot of vu... maybe use faders in the sub busses, planning to cut with the dril press and a cutting wick.

JS

 

[r2d2]

cooooooool project !

any scheme about pan+assign card?

peace
r2d2