remote volume controller , ideas welcome

[andre tchmil]

I'm planning to make a DAW monitor controller and want to keep the wiring path as short as possible.
So my idea was to make all the switching (mono, dim, mute, etc) with relais on a pcb close to the AD/DA.

The only problem for me is the level control, either stepped or log.

Any ideas for a HQ balanced remote system with a pot meter ?

 

[andre tchmil]

Oops , did a search here and came up with alot of examples.

http://stiftsbogtrykkeriet.dk/~mcs/

http://www.groupdiy.com/index.php?topic=655


But seems all soooooo difficult for me to DIY.

Have lots of HQ relais and a very nice mono Alps pot with a big aluminium knob for the control.

Can anyone help me with the PCB etc ?

 

[TomWaterman]

Hey, can't really help with the PCB but MCS's stuff will work for you and he has boards I think.

Anyway, something I've been meaning to investigate was a way to have a pot control a voltage which feeds say 3 LM3914/5/6 bargraph drivers.

If you run them in cascaded dot mode and use the pot to vary a voltage feeding their inputs they can effectively control a bank of relays to switch on or off.

You'd get a 30 step volume control and can set specific attenuation levels for each step by building the appropriate balanced or unbalanced pads.

Alternatively you may be able to run the drivers in bargraph mode and have 2dB per step attenuation for each of the 30 steps...60dB in total.

Hmmm I must think about this one more as its a fair bit simpler than a microcontroller.

Good luck!
Tom

 

[andre tchmil]

Thanks Tom,
But that sounds still like Chinese to me.

 

[Kev]

Mikkel has a couple of relay PCB's ready to go
I hope one of the new ones will be part of the DIY Factory in the future.
I can't find my reference to his site ???
someone help
http://electronics.dantimax.dk/Kits/index.html
thanks google
but there is another one behind the scenes

I have a simple VCA based unit
which will suite many people and should suite all for headphone cues and secondary monitoring.
http://www.diyfactory.com/projects/dawmonswitch/dawmonswitch_2.htm

basically its the SSM I/O chips with an LM833 buffer and the THAT VCA.
a couple of relays to acheive the Dim Cut and Mono thing.

add the Talk Over IFB unit with user set dim and most people are happy.
http://www.diyfactory.com/projects/talkback/talkback.htm

 

[drpat]

...

 

[mcs]

I do have something ready (almost) - a relay board for some switching is missing.

What is ready, is the attenuator board: http://electronics.dantimax.dk/Kits/Foto/RelVol3-PCB-photo.495_400.jpg

[edit]That photo shows a stereo version. Only 6 relays are used for a 64-step balanced attenuator.[/edit]

And the control board, which is this one: http://electronics.dantimax.dk/Kits/Foto/Remote8.495_400.jpg
- but with some special software.

The features I made in the software (if I remember correctly) are:

- Stereo, mono, mono-l and mono-r modes (the missing part is the relay circuit for that switching).
- programmable dim settings
- mute

The volume it set on a rotary encoder (or using an IR remote).

The schematic and test results from the prototype attenuator board are here - somewhere :grin:

Best regards,

Mikkel C. Simonsen

 

[PRR]

> make a DAW monitor controller

> I'd eventually like to have a remote gain control for all of my external mic pres

These are two VERY different problems.

Monitoring, you have a "standard" and fairly level which has to be reduced.

Mike preamps start with low and very variable levels. The gain control is typically deeply embedded in the design.

> a pot control a voltage which feeds say 3 LM3914/5/6 bargraph drivers.

Or just LED-LDR opto-isolators. No clack. The ills of LDRs (poor matching and marginal distortion) vanish when you use them as slow/soft switches.

 

[TomWaterman]

Hmmm like it PRR.

I'll have to look into that opto thing as it may be a cool solution and free of potential clicking problems too. Wonder about distortion of the audio path - would there be any (likely) ?

Mikkel - looking very good my friend. Nice features. What type of attenuator is that?

Cheers Tom

 

[mcs]

[quote author="TomWaterman"]Mikkel - looking very good my friend. Nice features. What type of attenuator is that?[/quote]
I don't think it has a name... Each stage has a certain attenuation (1dB, 2dB, 4dB etc.), and the stages are then switched in or out of the chain. The resistors are calculated so the load will be the same for each stage no matter how many of the following stages are used (those formulas took some work to get done...).

There are no clicks BTW, as long as theres's no DC in the signal.

Best regards,

Mikkel C. Simonsen

 

[TomWaterman]

Excellent!

I presume its unbalanced stereo but one board can be used for balanced mono?

Do you happen to have a schemo for it available?
-Tom

 

[mcs]

[quote author="TomWaterman"]I presume its unbalanced stereo but one board can be used for balanced mono?[/quote]
No, balanced stereo actually (6 relays per. channel).

Do you happen to have a schemo for it available?

Yes, page 6, top post here: http://www.groupdiy.com/index.php?topic=655&start=75&postdays=0&postorder=asc&highlight=

I also have a lot of nice Gustav PCBs :green:

Best regards,

Mikkel C. Simonsen

 

[cannikin]

this is fantastic :thumb:

I've wanting to do something like this for a while.

A master volume control for the output to my Speakers (software faders are a pain) and monitor switcher. Very Cool!

 

[tony dB]

is it something like a big k nob from meckie you're after?

But then operated by remote if I understand well?

 

[yan_b]

i started something based on this controller
http://www.oopic.com/oopicr.htm
as a remote unit, and some i2c i/o chips in the main box that will connect to something like mcs relay fader.
my main idea is to use one amp for few speakers , using some kind of trim memory for each speakers set ,and switching relays befor and after the amp.

the programming is really easy , i dont have any background in programming pic's etc..., and i find it easy enough.

 

[Guest]

Frank over at the SoS forums has started up a similar thread.. (along with some good newbie stuff for people like myself)

http://www.soundonsound.com/forum/showflat.php?session=5061af3bb4637f642bd60906442ae747&Cat=&Number=118645&page=0&view=collapsed&sb=5&o=&fpart=1