GroupDIY

General Discussions => The Lab => Topic started by: pahstah on October 12, 2015, 09:16:15 AM

Title: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 09:16:15 AM
Hi Everyone,

i'm in the final stage of prototyping a little modular mixer based on a schematic that I've found in a thread in this forum. it's a very basic mixer but it will suit my need for tracking/monitoring and maybe it will be nice to have, comes mix time, for adding some extra juice.

here are some pictures

Paolo


 I've uploaded a rough mix of a puremix contest song redone on my diy console. check it out at:

https://soundcloud.com/paolo-stabellini/gearfest-puremix-contest-oh-baby-console

and a video:

https://youtu.be/T8X_4ZyNqs4

Paolo
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 09:17:28 AM
Front
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 09:18:23 AM
500 bucket detail
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 09:19:50 AM
Channel Fader Detail
Title: Re: DIY Modular Mixer
Post by: Joechris on October 12, 2015, 10:07:14 AM
Looking very good!! A lot of talk about modular mixers...nice to see some photos of real work :-)
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 10:13:35 AM
Tank you Joechris, it's been two years in the making but now i'm finally seeing the end of it... at least for the mixer part, but as you can see, there is a whole lot of possibilities in the pre eq section
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 11:06:20 AM
EVEN 3701 module...
Title: Re: DIY Modular Mixer
Post by: joaquins on October 12, 2015, 11:28:18 AM
I did put myself in a trip like this, at the moment I found a problem to get the PCBs made and the front panels. I did solve the PCB thing with a very nice method for self etching with really nice results but no time since then, still have to solve the metalwork.

 Looks really nice! I wish you a smooth arrival to destination.

JS
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 11:59:14 AM
Thank you Joaquins, I'm am testing the control room module right now, there are some minor mistakes but it should be easy to solve them. when the CR module is ok next move is to complete the metalwork and then put it at work on some session

paolo
Title: Re: DIY Modular Mixer
Post by: peterc on October 12, 2015, 02:02:26 PM
Looks great, nice idea

Peter
Title: Re: DIY Modular Mixer
Post by: pahstah on October 12, 2015, 03:01:54 PM
Thank you Peter.
There are many ways to configure this little mixer, as I think you have guessed...
Title: Re: DIY Modular Mixer
Post by: pahstah on October 13, 2015, 06:26:10 AM
Submaster + Aux section
Title: Re: DIY Modular Mixer
Post by: ruffrecords on October 14, 2015, 05:26:19 AM
Well done. I like the idea of keeping all  the routing, AUXes and PAN in the same plane as the fader with just the EQ and pre on the sloping part. I am particularly interested in the mechanical aspects. I see you have used profiled sides held together with extrusions which is basically the scheme most pro mixers adopt. The hard part is where two such profiles butt up against each other like in the centre of your mixer. I am never quite sure how thick the profiles need to be for use with countersunk screws - any tips?

Cheers

Ian
Title: Re: DIY Modular Mixer
Post by: beatnik on October 14, 2015, 06:14:43 AM
very nice. congratulations !

what are the mic pre /eq modules based on ?
Title: Re: DIY Modular Mixer
Post by: pahstah on October 14, 2015, 12:33:09 PM
Quote
Well done. I like the idea of keeping all  the routing, AUXes and PAN in the same plane as the fader with just the EQ and pre on the sloping part. I am particularly interested in the mechanical aspects. I see you have used profiled sides held together with extrusions which is basically the scheme most pro mixers adopt. The hard part is where two such profiles butt up against each other like in the centre of your mixer. I am never quite sure how thick the profiles need to be for use with countersunk screws - any tips?

Cheers

Ian/quote]

hi Ian,
thanks for the kind words.
the lateral cheek is 3mm thick  and the countersink is the standard countersink in front panel designer for 5mm screw 74A, but maybe is better an hole for allen screw 74B.
I hope that I have answered your question.

Paolo
Title: Re: DIY Modular Mixer
Post by: pahstah on October 14, 2015, 12:42:22 PM
very nice. congratulations !

what are the mic pre /eq modules based on ?

Hi beatnik, thank you.

the two models on the left are EVEN 3701:  my way to squeeze an 1073 in a double500 module.
In the other two (with the colored knobs ) I've put an a.p.i. pre/line togheter with an helios eq so I called them APHELIOS.
One good thing about this double high 500 module is the possibility to have a mic input AND a line input without the need of an attenuator at the mic input.
And I have other possible mashups of pre and eq.
Another plus in having a faceplate that is so high is that you have much more space to place the controls, so the knobs aren't cramped and you don't need concentric switches (wich are expensive and difficult to find).

Paolo
Title: Re: DIY Modular Mixer
Post by: pahstah on October 17, 2015, 11:20:06 AM
Almost finished
Title: Re: DIY Modular Mixer
Post by: pahstah on October 17, 2015, 11:42:25 AM
Rear panel
Title: Re: DIY Modular Mixer
Post by: pahstah on October 17, 2015, 11:46:33 AM
Routing
Title: Re: DIY Modular Mixer
Post by: pahstah on October 20, 2015, 07:41:19 AM
These are the channel pcb and the master bus pcb. The master bus pcb uses that 1646 as line out, but there's a mod to use transformer out.

paolo
Title: Re: DIY Modular Mixer
Post by: abbey road d enfer on October 20, 2015, 07:56:52 AM
Very nice build! Congrats.
You sem to have overcome most of the obstacles that abut DIYers.
For the members' education:
How have you designed the metal work (CAD, pen andpaper, twine and chewing gum ;) )?
Did you do the metalwork yourself or have a pro doing it for you?
What software and what fab for the PCB's?
Did you have to order thousands of pots or have you found a supplier that has them available at a price that's less than an eye and a kidney?
Title: Re: DIY Modular Mixer
Post by: pahstah on October 20, 2015, 09:37:35 AM
Thank you Abbey.
It's been a great effort, brain and time consuming, and it's been expensive considering all the mistakes that I've made. and it's not finished yet... I need to design the panels to cover the top and the bottom.
For the design of the lateral panels I used e-machine shop, then i exported the dxf to front panel design and made the holes, and then sent the files to schaeffer. for the rectangular panels I designed them directly in FPD.
For pcb I used Kicad ( the learning curve is not too steep but only now, after two years of using it and many pcbs designs made, I feel  confident), I then sent the gerber to real-pcb. I'm very satisfied with the results.

Title: Re: DIY Modular Mixer
Post by: pahstah on October 20, 2015, 10:04:06 AM
About the pots: I've chosen a supplier that has them along with the dedicated  knobs ( these are concentric knobs ) at a reasonable price. these are alpha concentric post and have a nice feeling when you rotate them.  The panpots are clarostat that i bought from Jeff Steiger of CAPI. those were expensive but the pcb has holes for a cheaper but very good alternate stereo pot with center detent. So, if there will be interest in this project, it will be easy to source the panpots.

about the extrusions: these are the most difficult parts of the project, and had me scratching my head for a long time before I found the right ones, and still they were 60TE, 84TE or 1 meter long.
in order to have different lengths I should have made  order in hundreds.. so I adapted my design around those lengths.
So I used the 84te long extrusions wich is about 11x 500 series wide ideal for 8 input channels plus three master channel in the flat part of the mixer and a three space  wide control room module.
and the 60te long extrusions for the 8 input channel expander. with this configurations you are limited to 2 stereo submaster and one master module... enough for a small mixer.
...BUT...
If you want more submaster channels in mono and additional slots in the Double500 portion of the mixer, you can use the 60te extrusions like this: two 60te wide modules for 16 input channels and one 60te wide module for 8 submaster mono modules and one  master module, the control room module and you have 10 500 series spaces left in the sloping part of the mixer.
Title: Re: DIY Modular Mixer
Post by: pahstah on October 20, 2015, 10:24:54 AM
One more thing: I used one big front panel to hold all the channel modules together because it is way cheaper than have one front panel for every module, but this is only for the proto because I didn't wanted to have 8 single front panels made, only to later find that they had mistakes. obviously the ideal solution is to have one front panel for module, since it's way way easier to insert or remove the channel  this way.
As you can see in the picture, I've used a motherboard pcb instead of ribbon cable for the buses, this creates some problems during the insertion of eight modules held togheter by a single front panel..
Compromises as usual...

Paolo
Title: Re: DIY Modular Mixer
Post by: pahstah on October 20, 2015, 04:02:28 PM
One big problem that i encountered during this build has been the need of different standards between metric and imperial hardware, for example i had to source screws from digikey to use with faders and with L brakets. The output transformer had holes too small for a 3mm screw to fit into, i had to find 2,5 mm screws....wich are nearly unobtainable in Italy...
Many parts had to be sourced from different suppliers, for example i didn't find a supplier for e-switches in europe so i had to use digikey, but digikey didn't had that1646... And so on ... But I think everyone in this forum encountered such problems before.
Title: Re: DIY Modular Mixer
Post by: pahstah on October 26, 2015, 04:48:25 AM
hi everybody,
 I've uploaded a rough mix of a puremix contest song redone on my diy console. check it out at:

https://soundcloud.com/paolo-stabellini/gearfest-puremix-contest-oh-baby-console

and a video:

https://youtu.be/T8X_4ZyNqs4

Paolo
Title: Re: DIY Modular Mixer
Post by: pahstah on October 28, 2015, 04:27:12 AM
Now i'm working on a mic pre to go with the mixer channel. I've kept the space for another pcb to be placed along with the channel pcb.
Title: Re: DIY Modular Mixer
Post by: clister01 on October 29, 2015, 02:50:39 AM
This is AMAZING. Great work... when it's all said and done it would be incredible if you can share all the files for the boards and metal work. An eight channel version would be perfect for me and I suspect more than a few others.

Really one of the best builds I've seen on here...
Title: Re: DIY Modular Mixer
Post by: pahstah on October 29, 2015, 07:27:52 AM
Hi Clister01,

thank you for your words.

two years ago I was looking at Jeff Steiger's mixer project hoping that he could sell parts for a complete mixer project because I'm a big fan of his work.
But then I decided to go my own way mainly because I had this idea of a double high 500 series module and this needed a specific system to be inserted into.
Now I'm near completion for the mixer part, and in the meantime i've designed the two Double500 modules you see in the pictures: the 1073 and the aphelios. the project can become a system, if the interest is high enough, and i can envision other designers, much more skilled than me, create their own double500 modules.

I'm also thinking about doing a single bay version with the mic pre inserted along with the channel as you see in the picture, but we'll see..

I'm not sure yet what to do with this project, it will surely be used by me for my session, but i'm also thinking about selling pcbs and metalwork for other diy'ers to create their own mixer.

But before all that, I must verify that everything works as it should.

what do you think?

Paolo
Title: Re: DIY Modular Mixer
Post by: tmuikku on October 29, 2015, 08:13:57 AM
Jeah why not if you get the design road tested and measure good there shall be buyers, me included :)
Title: Re: DIY Modular Mixer
Post by: pahstah on October 29, 2015, 04:05:26 PM
Jeah why not if you get the design road tested and measure good there shall be buyers, me included :)

I know that there's a lot of interest in projects regarding mixers/consoles, and I think that this project has the potentiality to satisfiy the needs of many recording enginers and enthusiasts, bear in mind though that this is a  very expensive project, not as expensive as buying a console with the same features, but still expensive. So it can remain just an interest, and nothing more.
Title: Re: DIY Modular Mixer
Post by: tmuikku on October 29, 2015, 04:40:16 PM
indeed its expensive, but the routing module for example is versatile enough but still seems to be rather simple in construction. also you've got provision for chip amps and possibility to skip at least some transformers.

many projects here that are too simple to be usable, or too complicated or just not happening past the feature list and front panel drawings :)

 anyway, great read and inspiration, thanks! the more i look the pictures the more clever things i find, you've done loads of thinking. it looks more of a ready product than prototype. next i need to read what capi rele are  8)
Title: Re: DIY Modular Mixer
Post by: pahstah on October 30, 2015, 04:52:43 AM
indeed its expensive, but the routing module for example is versatile enough but still seems to be rather simple in construction. also you've got provision for chip amps and possibility to skip at least some transformers.

many projects here that are too simple to be usable, or too complicated or just not happening past the feature list and front panel drawings :)

 anyway, great read and inspiration, thanks! the more i look the pictures the more clever things i find, you've done loads of thinking. it looks more of a ready product than prototype. next i need to read what capi rele are  8)


the routing module gave some headache because of the small space i was putting it into. i had to find the way to put two subgroups in a single 500 series space width along with two auxes and the provision for a switchable insert for the groups. the pcbs space was very small, that's because i decided at the begin of the project that this would have been a small portable mixer, so i had to scrap the transformers ( but there's the possibility to use them if you want with some additional cabling outside the pcbs ) and use a stereo fader instead o two mono faders wich is not ideal i think.
the metalwork obviously was the most frustrating of the lot but i think i managed to solve all the issues i had.
Title: Re: DIY Modular Mixer
Post by: pahstah on November 06, 2015, 01:27:35 PM
This is the neve 1073 in double500 format
Title: Re: DIY Modular Mixer
Post by: pahstah on November 08, 2015, 11:53:38 AM
Troubleshooting control room module
Title: Re: DIY Modular Mixer
Post by: pahstah on November 19, 2015, 01:05:45 PM
Ooops...!
Title: Re: DIY Modular Mixer
Post by: pahstah on January 15, 2016, 07:53:13 AM
coming together nicely..

(http://s16.postimg.org/7q3gl5v79/DSC0076.jpg)
Title: Re: DIY Modular Mixer
Post by: pahstah on January 15, 2016, 07:55:18 AM
I think I will do a rack version for double500 modules

(http://s15.postimg.org/72iykk1rv/DSC0078.jpg)
Title: Re: DIY Modular Mixer
Post by: Whoops on February 02, 2016, 03:13:04 PM
What a great ideia and build!!!

Congrats
Title: Re: DIY Modular Mixer
Post by: pahstah on February 03, 2016, 01:07:40 PM
Thank you whoops!
Title: Re: DIY Modular Mixer
Post by: clister01 on March 05, 2016, 08:30:01 PM
Did you ever finish putting this thing together?  Great choices on the functionality you've decided to put into it. Great tracking channels with the double 500 format, a couple of busses (people don't need 8 or 16 these days), along with a center section make this totally ideal... at least for me and small project studio setup.

If you had some issues with the monitor controller maybe Jeff could help you out? I know he built a module of his own a few years back that seemed pretty cool.

Would be amazing if you decided to share PCBs and whatnot... I'm just dreaming of having a pair of CAPI pre's and EQs in the double 500 format for a tracking mixer :-)
Title: Re: DIY Modular Mixer
Post by: pahstah on March 06, 2016, 06:34:25 AM
Did you ever finish putting this thing together?  Great choices on the functionality you've decided to put into it. Great tracking channels with the double 500 format, a couple of busses (people don't need 8 or 16 these days), along with a center section make this totally ideal... at least for me and small project studio setup.

If you had some issues with the monitor controller maybe Jeff could help you out? I know he built a module of his own a few years back that seemed pretty cool.

Would be amazing if you decided to share PCBs and whatnot... I'm just dreaming of having a pair of CAPI pre's and EQs in the double 500 format for a tracking mixer :-)

Clister1, yes this thing is in its final steps, i've managed to fix all the mistakes that i've made and i got rid of the noise in the summing section wich was too high, now is at a rasonable level. in the meantime i've bult an helios type69 module in double500 format, you can see it here:
http://realgearonline.com/thread/4451/optimal-helios?page=3

i'm thinking about making a kit for this project. it could be a really nice project for those who want a tracking mixer with the possibility to utilize 500 series format, wich now is hugely widespread, without the need to spend a massive amount of money in a commercial mixer.
the problem is that i need to rearrange the dimensions of this thing: i need more space in the bottom for the channel modules so it will be at least 5 cm tall, and i will definitely separate the fader bucket from the channel bucket in order to host zamproject's automation.  so it will become bigger and i don't know if this is gonna be okay for some people interested in it...
Title: Re: DIY Modular Mixer
Post by: clister01 on March 10, 2016, 03:41:53 PM
Smaller would be more ideal for someone like me, but I can't imagine this thing turning out to be enormous even with those changes... I'd still be interested :-)
Title: Re: DIY Modular Mixer
Post by: pvision on March 10, 2016, 05:28:08 PM
I love the 6U channel modules. 3U is so tiny!

Nick Froome
Title: Re: DIY Modular Mixer
Post by: pahstah on March 11, 2016, 03:35:51 AM
Smaller would be more ideal for someone like me, but I can't imagine this thing turning out to be enormous even with those changes... I'd still be interested :-)

i'm in the stage of making revision for the console, fix some pcbs errors and defining mechanical parts better.
I need to add 3 cm at the bottom outline of the lateral cheek because i need more space for the connectors on the channel's backplane, now is 10 cm high the new version will be 13 cm high with maybe a lightly  slanted profile in the channel.
maybe bring the busses from 8 to 4 and add 2 more auxes.

how many channels are you interested in?
Title: Re: DIY Modular Mixer
Post by: clister01 on March 11, 2016, 07:46:21 PM
8-12 Channels would be great, master section, 4 busses is fine as well (as long as you've got direct outs on every channel) with the 3 auxes... sounds perfect  :)
Title: Re: DIY Modular Mixer
Post by: pahstah on March 13, 2016, 05:04:03 AM
Cameron, the mixer's design is based on a eight modules bucket, so you can add eight channel at a time. So it is 8 16 24 etc..
It has direct outs for every channel.
Note that if you want you can put 16 preamps in the double500 bucket, eight of them will go into the channels to the direct out to converter, the remaining eight will go directly to the converter. So you can record 16 tra ks. The only downside is that you won't hear the latters through the console's master bus or auxes, but only through daw's returns
Or you can use eight external preamps and send them to channels and have 16 500 series preamp in the bucket to a total of 24 preamps, altough you'll only hear the eight in the channels through the mixer's monitor
Title: Re: DIY Modular Mixer
Post by: clister01 on March 13, 2016, 07:33:14 PM
Sounds awesome. I'd probably start with an 8 channel version myself. Any chance of an insert switch for a point between the two 500 series spaces? I'm sure something could be added on afterwards so no worries if not.
Title: Re: DIY Modular Mixer
Post by: pahstah on March 14, 2016, 03:49:55 AM
yes, i've obviously thought about an insert switch between modules and is already present in the channel design, what i've not designed yet is the pcb with the relays on the back of the mixer, but will be next in line

Paolo
Title: Re: DIY Modular Mixer
Post by: pahstah on March 14, 2016, 07:14:39 AM
armrest in place...

(http://s22.postimg.org/r7o5bby6p/DSC0007.jpg)
Title: Re: DIY Modular Mixer
Post by: iprovlek on March 14, 2016, 07:23:25 AM
Hi Pahstah!

Is this modular mixer be available like the kit!?
Title: Re: DIY Modular Mixer
Post by: pahstah on March 14, 2016, 12:04:18 PM
Hi Pahstah!

Is this modular mixer be available like the kit!?

this is what i'm planning to do
Title: Re: DIY Modular Mixer
Post by: Whoops on March 14, 2016, 07:50:25 PM
Outstanding work, looks beautifull
Title: Re: DIY Modular Mixer
Post by: pahstah on March 15, 2016, 12:55:41 PM
thank you Whoops!  :)
Title: Re: DIY Modular Mixer
Post by: Krcwell on March 15, 2016, 10:20:14 PM
Outstanding!

What is the front covering? Almost looks like leather in the pic.
Title: Re: DIY Modular Mixer
Post by: clister01 on March 15, 2016, 11:03:57 PM
armrest in place...

(http://s22.postimg.org/r7o5bby6p/DSC0007.jpg)

WOW
Title: Re: DIY Modular Mixer
Post by: pahstah on March 16, 2016, 04:09:42 PM
Outstanding!

What is the front covering? Almost looks like leather in the pic.

Yes it is leather a woodblock on the inside and some soft material in between
Title: Re: DIY Modular Mixer
Post by: clister01 on March 16, 2016, 11:12:16 PM
yes, i've obviously thought about an insert switch between modules and is already present in the channel design, what i've not designed yet is the pcb with the relays on the back of the mixer, but will be next in line

Paolo

Well then I think you've thought of everything!
Title: Re: DIY Modular Mixer
Post by: iprovlek on March 17, 2016, 08:08:40 AM
Faders, pans, switches are separately!?

That you can put any preamps and eqs!


LOOKS AMAZING Pahstah!!!
Title: Re: DIY Modular Mixer
Post by: zamproject on March 17, 2016, 09:51:56 AM
Hi Pahstah

What an nice work !!!
"DIY" definitely step up recently with Ian/Holger tube mixer and now yours.
Looking forward to retrofit a moving fader system  ;)

Best
Zam
Title: Re: DIY Modular Mixer
Post by: pahstah on March 17, 2016, 02:26:45 PM
Hi Pahstah

What an nice work !!!
"DIY" definitely step up recently with Ian/Holger tube mixer and now yours.
Looking forward to retrofit a moving fader system  ;)

Best
Zam


Zam, that would be the icing on the cake!
I'm already thinking  about a version of this mixer with a separate fader bucket for your moving faders 
This forum and its member are the best!!!

Paolo

 P.s. Let's not forget Gary 's Sphere
Title: Re: DIY Modular Mixer
Post by: pahstah on June 27, 2016, 06:10:16 AM
mixer's done! loaded with 8 helios 69, 2 nv 1073, 2 aphelios, and 4 capi vp28 as line input. i solved the noise problem in the summing part of the console and i've found that aux sum is has less noise than group and 2bus sum!

(https://s32.postimg.org/qspqx5oud/IMG_3736.jpg)
Title: Re: DIY Modular Mixer
Post by: beatnik on June 27, 2016, 07:35:17 AM
good job !
Title: Re: DIY Modular Mixer
Post by: Timothytitus88 on June 27, 2016, 07:50:16 AM

Indeed! just marvelous!
T
Title: Re: DIY Modular Mixer
Post by: iprovlek on June 27, 2016, 07:58:12 AM
Great Pastah! 8) 8) 8)
Title: Re: DIY Modular Mixer
Post by: Rocinante on June 27, 2016, 10:16:32 AM
Congratulations!  What an inspiration!  Looks beautiful!
Title: Re: DIY Modular Mixer
Post by: audiomixer on June 27, 2016, 10:20:40 AM
I like it a lot, great looking piece of kit!

- michael
Title: Re: DIY Modular Mixer
Post by: zamproject on June 27, 2016, 12:03:05 PM
Hi Pahstah

Absolutely great !
Bravo !!!!

Best
Zam
Title: Re: DIY Modular Mixer
Post by: benqbasic on June 28, 2016, 02:18:08 AM
Wow that thing looks fantastic. Nice work
Title: Re: DIY Modular Mixer
Post by: pahstah on June 28, 2016, 07:17:10 AM
Thank you so much for the appreciations guys!

her's a shot of the helios channels

(https://s32.postimg.org/vwnl31739/DSC0036.jpg)
Title: Re: DIY Modular Mixer
Post by: anjing on June 28, 2016, 09:58:50 AM
beautyfull work....what did you use to close the gaps between the buckets?

Regards,

Pierre
Title: Re: DIY Modular Mixer
Post by: pahstah on June 29, 2016, 04:36:42 AM
Hi Pierre,

there is no gap between the buckets because these are two buckets put together with screws

(https://s31.postimg.org/pofj7z2a3/DSC0070.jpg)

in this image you see the 8 channel bucket on the right but in the previous image you see that i've put the 8 channel bucket on the left.
I could have made a 16 channel mixer directly with the right length of rails but at the beginning i was going for an eight channel mixer

paolo

Paolo
Title: Re: DIY Modular Mixer
Post by: fragletrollet on April 17, 2017, 07:33:02 AM
Hello!

Old thread I know, but worth a bump anyways.

Beautiful build. I was wondering; if you don`t mind, why not post pcb and metalwork drawings/schematics here? I know I would appreciate it to use as starting points for designing my own modular mixer. Maybe you have .fpd and pcb files even? So much learning potential  8)