Going to API mixer(Something to use with 2-ACA-Bo)

[ForthMonkey]

I'm thinking to buy 2-ACA-Bo PCB and build 8 channel summing amp/line mixer.For channel i changed Forssell 8ch sum design and made something like this.

Channel boards!

------------------------------------------

My references to build this;

Forssell 8 ch sum

http://www.forsselltech.com/media/attachments/8chsum_1.pdf

------------------------------------------

Channel Design

API balanced transformerless amplifier

http://www.davegroupjapan.com/api2520_02.gif

And my design.I added simple mechanical mute,too.And removed DIP8 op amp option.

------------------------------------------

Board Design

I want to buid it to use with 15 pin edge connector and also without edge connector.I added some via to use without connector.

------------------------------------------

Bus Selector Design

Self etch files for bus routing section.Simple stereo buses.8 stereo bus and a master bus.

Schematic

https://dl.dropboxusercontent.com/u/91809016/SUM/Bus%20Select/Schematic.pdf

Bottom

https://dl.dropboxusercontent.com/u/91809016/SUM/Bus%20Select/Bottom.pdf

Layout

https://dl.dropboxusercontent.com/u/91809016/SUM/Bus%20Select/Top.pdf

------------------------------------------

Back Board Design

Not necessary but it's good to make it compact and clean.Made for minimum 4 channels.Using with rails is good idea.Cause channel pcb is not too long.So back pcb can't fit to pack panel.I added simple molex connectors to connect in,out and power.I don't want to fight with inside cables.Only in,out and power.

Self-etch files

Bottom

https://dl.dropboxusercontent.com/u/91809016/SUM/Back_Bottom.pdf

Layout

https://dl.dropboxusercontent.com/u/91809016/SUM/Back_Top.pdf

------------------------------------------

MOD1 Discrete op amp

I just made in with Eagle.It's already exist but there was no gerber.

http://sureshotstudio.blogspot.com.tr/2011/09/urei-mod-1-opamp.html

Gerber Files

https://dl.dropboxusercontent.com/u/91809016/MOD1/MOD1.rar

Self-etch file for 40 pieces.

https://dl.dropboxusercontent.com/u/91809016/MOD1/Self-Etch.pdf

Thanks.

 

[iprovlek]

I tried this Forssell 8 summing without driver output,passive with pan pots and worked very well!

This can be good start ....


Thumb

 

[iprovlek]

You are amazing Forthmonkey!

 

[ForthMonkey]

Oh,thanks iprovlek.

BTW i added new circuit with simple mute section.It's just and option.And here is 3D board...

 

[tmuikku]

another cool small project from you. have you considered adding decoupling caps for opamp psu rails? i tried to hint this moons ago on your other project

see this, must be the thread of the subject http://groupdiy.com/index.php?topic=37307.0

 

[ForthMonkey]

another cool small project from you. have you considered adding decoupling caps for opamp psu rails? i tried to hint this moons ago on your other project

see this, must be the thread of the subject http://groupdiy.com/index.php?topic=37307.0

Thanks for reply and advice.I was thinking about to add decoupling caps,too.I will read all thread.  ;D Thanks again!

 

[Joechris]

I dont think that the 2520 would be very happy with its output conected to ground via the mute switch.....??
I belive the top of the fader should be conected to ground.

 

[ForthMonkey]

Ok.I updated first post.What do you think now?

 

[iprovlek]

Mute section is clever....

And often required!

 

[ForthMonkey]

I added front panel and board designs,too.Just some small steps...

 

[ForthMonkey]

I updated first post and added MOD1 gerber files.I will use MOD1 instead of 2520 because of money.  ;D

 

[Humner]

wow, this is really cool. I'm in somewhat of the planning stages of my own summing mixer, but want to add EQ and compression for each channel. I really like a lot of your projects and designs, very small and modular.

have you built any MOD1's? Have more details? BOM etc?

 

[ForthMonkey]

wow, this is really cool. I'm in somewhat of the planning stages of my own summing mixer, but want to add EQ and compression for each channel. I really like a lot of your projects and designs, very small and modular.

have you built any MOD1's? Have more details? BOM etc?

With 500 series this project could be good,i guess.Or you can build 500 series modular console with CAPI products.

MOD1 info.I made simple booster with this op amp.Working good.

http://sureshotstudio.blogspot.com.tr/2011/09/urei-mod-1-opamp.html

 

[Humner]

excellent, thank you.

 

[Joechris]

Hmm..you still short the amp with the mute if the fader is on top...

 

[ForthMonkey]

Hmm..you still short the amp with the mute if the fader is on top...

What do you suggest? Should i send GND or leave blank?

 

[ForthMonkey]

Then i asked  that why it has no insert!? And i added.See first post.

 

[ForthMonkey]

Updated first post.Added master channel design.

 

[ForthMonkey]

No idea about bus,any one?

 

[ForthMonkey]

Added MOD1 op amp self-etch file for 40 pieces.