bwithwings
Member
- Joined
- Mar 11, 2009
- Messages
- 6
Hi list
Long time reader / builder, first time poster I've built quite a few gadgets with the help of this list and others, solid state and glass, but this time I would like some advice before I jump in head first!
My band needs a mixer. We can't really use anything off-the-shelf that I've found so far, as we need it to fit into 1U or 2U and we do things quite a specific way, so I've decided to build up a mixer that will give us the functionality we use. If anyone could give me any advice, that would be great!
Firstly, apologies for my budget MS Paint schems
We have about a dozen analog synths and drum machines, currently we use two horrible SM Pro 8-channel DI strips which have mixers built into them:
What I'd like to do instead is:
Inputs are all unbalanced line level, I would probably use simple jack switching to detect mono or stereo and send any mono signals to both inputs. Pan and level control on each input, and an on-off-on bus selector switch, A/mute/B. We would probably want to expand to anywhere up to 16 stereo input channels, starting with 10.
Each of the stereo buses would have a level control, balanced outs (to send to the stage box), and an unbalanced insert. I'd also like to put unbalanced outs on each bus.
Maybe someone can point me in the right direction!
INPUT STAGE
Here's a rough-up of what I was thinking... but I'm not sure where to put the DC coupling caps. Right after the input jacks makes sense, but then they would have to be massive, I could use much smaller & better caps just before the voltage follower. Any thoughts? I could also use transformers but sadly I am not made of cash ;-)
Also, maybe it's better to move the volume/pan stuff after the followers?
SUMMING MIXER
I've had a good read here:
http://www.groupdiy.com/index.php?topic=27992.msg337446#msg337446
Radiance seemed to get great performance without using a servo, so I'll give that a go too. I'm not sure how he went about selecting what opamps to use tho? Being more of a tube guy myself... I could just plug & play his summing amp schem for both sides of both buses.
I have used the THAT line driver chips in a Pico compressor and the AD equivalents in Kev's LA-4 clone, so I know how to use them and am happy with that as the balanced & unbalanced output driver.
UNBALANCED INSERTS
I could use some advice on a good way to add unbalanced inserts into the signal chain though? My initial thought is like this:
Thanks for any and all comments!
Darren
Long time reader / builder, first time poster I've built quite a few gadgets with the help of this list and others, solid state and glass, but this time I would like some advice before I jump in head first!
My band needs a mixer. We can't really use anything off-the-shelf that I've found so far, as we need it to fit into 1U or 2U and we do things quite a specific way, so I've decided to build up a mixer that will give us the functionality we use. If anyone could give me any advice, that would be great!
Firstly, apologies for my budget MS Paint schems
We have about a dozen analog synths and drum machines, currently we use two horrible SM Pro 8-channel DI strips which have mixers built into them:
What I'd like to do instead is:
Inputs are all unbalanced line level, I would probably use simple jack switching to detect mono or stereo and send any mono signals to both inputs. Pan and level control on each input, and an on-off-on bus selector switch, A/mute/B. We would probably want to expand to anywhere up to 16 stereo input channels, starting with 10.
Each of the stereo buses would have a level control, balanced outs (to send to the stage box), and an unbalanced insert. I'd also like to put unbalanced outs on each bus.
Maybe someone can point me in the right direction!
INPUT STAGE
Here's a rough-up of what I was thinking... but I'm not sure where to put the DC coupling caps. Right after the input jacks makes sense, but then they would have to be massive, I could use much smaller & better caps just before the voltage follower. Any thoughts? I could also use transformers but sadly I am not made of cash ;-)
Also, maybe it's better to move the volume/pan stuff after the followers?
SUMMING MIXER
I've had a good read here:
http://www.groupdiy.com/index.php?topic=27992.msg337446#msg337446
Radiance seemed to get great performance without using a servo, so I'll give that a go too. I'm not sure how he went about selecting what opamps to use tho? Being more of a tube guy myself... I could just plug & play his summing amp schem for both sides of both buses.
I have used the THAT line driver chips in a Pico compressor and the AD equivalents in Kev's LA-4 clone, so I know how to use them and am happy with that as the balanced & unbalanced output driver.
UNBALANCED INSERTS
I could use some advice on a good way to add unbalanced inserts into the signal chain though? My initial thought is like this:
Thanks for any and all comments!
Darren