JPK

Monitor Controller
« on: July 15, 2014, 05:32:02 AM »
This is a product we are working on that could be of interest for some forum members.
It will be available as a kit.



- 6 stereo sources, selectable bal/unbalanced, -10dBV/+4dBu (2 XLR, 2 jack, 1 RCA, 1 RCA/front mini-jack),
- 4 stereo output or 3 output+sub, selectable bal/unbalanced (2 XLR, 2 jack),
- Relay driven passive stepped level control, 64 x 1dB steps,
- Dim, Mute, Mute left/Mute right, Mono, left-right difference,
- External Dim input for talkback,
- programmable input, output, Mono, Diff, Dim and global offsets,
- "Wire with gain" headphone amp with 2 programmable gains,
- Minimalistic audio path,
- Single buffer between input and output makes it independent of source and destination impedances,
- Controllable by an TV remote, with the ability of learning the IR orders,
- Expandable to surround by stacking several units,
- Fully differential throughout,
- All switching done by relays,
- No capacitor in the audio path,
- Bandwidth: DC to 250 kHz (-1dB),
- Distortion: immeasurable (by us).

After input switching, the circuit uses four unity gain buffers (one for each stereo differential signal), followed by four passive logarithmic ladder attenuators feeding the output selector.
The buffers are switched to provide gain when the input is a -10dBV level.
All switching is done by 39 relays controlled by a PIC microcontroller.
What this unit doesn't do: Mixing & Talkback.


« Last Edit: September 16, 2014, 11:57:42 AM by JPK »


flaheu

Re: Monitor Controller
« Reply #1 on: July 27, 2014, 03:31:41 AM »
Waouw !


Great !!!

Any idea when it will be available and at what cost ?
As MagnetoSound said:
"Sad lack of balls in today's bands, IMO"

Re: Monitor Controller
« Reply #2 on: July 27, 2014, 08:22:05 AM »
La classe !

Je n'ai jamais utilisé vos outils (pour l'instant), mais lorgne régulièrement le site et les nouveautés :)

----------

Some questions.

Is that also possible to use a wire remote troughs the link connector ?
How work the input/output selector? individual on/off ? Meaning for example 2 input can be send to one output.
Or "destructive" solo?

I like the "digitast" key switch, is there any chance for some hidden code into the pic allowing 808 step sequencer  :P ?

Best

Zam

JPK

Re: Monitor Controller
« Reply #3 on: July 28, 2014, 05:14:34 AM »
The MC624 should be hopefully available in September at 499€ (599 incl.VAT).
There is no wire remote available yet but the link connector will allow connecting one when/if available (depends if enough requests). I personally think an IR remote is very convenient.
The input selector is exclusive, allowing one input at a time (there is no mixer).
Same thing for the output selector, except output four which can be configured as a sub output and selected in addition to one of the first 3.
There is still some free program memory in the PIC microcontroller so it will be possible to add some more functionalities in future (like a 808).

Spiritworks

Re: Monitor Controller
« Reply #4 on: July 28, 2014, 08:57:16 AM »
Greetings Jean-Pierre.
That looks really nice, and will go nicely with that side car that I have been building. Looking forward to more information.

mylesgm

Re: Monitor Controller
« Reply #5 on: July 28, 2014, 09:29:43 AM »
Looks great, why no talkback?
Check my work at www.mylesmumford.com

JPK

Re: Monitor Controller
« Reply #6 on: July 30, 2014, 04:05:16 AM »
The talkback will be better handled in our future quad (or 5x if space allows) headphone amp unit. The monitor controller has a Dim input which can be activated by an external talkback system.

culteousness1

Re: Monitor Controller
« Reply #7 on: August 04, 2014, 11:05:09 AM »
- "Wire with gain" headphone amp with 2 programmable gains,

Any details on that headphone amp?

Cheers,
Carsten
"What's all this analog stuff anyhow?" - Bob Pease
"My favorite programming language is ... solder." - Bob Pease

kante1603

Re: Monitor Controller
« Reply #8 on: August 06, 2014, 07:38:21 AM »
Hello Jean-Pierre,

a very nice project indeed!
May I ask the following questions:

1.The jack inputs (stereo 3 & 4),are they balanced?
2.The meter outpus,are they balanced?
3.Where does it (the meter o/ps) pic up the signal (somewhere after the input selector before the monitor level I guess)?

Thank you in advance,best,

Udo.

P.S.:+1 on a wired (small) remote!
« Last Edit: August 07, 2014, 05:00:49 PM by kante1603 »

JPK

Re: Monitor Controller
« Reply #9 on: August 11, 2014, 10:03:06 AM »
The Headphone amp is based on a LT1206 current feedback amplifier. I will publish the schematic in a few days.

The jack inputs 3 and 4 are balanced,
The meter outputs are balanced,
You are correct, they take the signal after the input selector and buffer, before the functions switches (mono, diff, dim, ...) and level.


kante1603

Re: Monitor Controller
« Reply #10 on: August 11, 2014, 10:32:48 AM »
Thank you very much Jean-Pierre,looking forward to building one of them......my current controller is at the end of days now,hahaha.....

Best,

Udo.

flaheu

Re: Monitor Controller
« Reply #11 on: August 11, 2014, 10:52:19 AM »
I'm preparing my wallet for a kit !!!
but hush..... don't tell my boss (wifey) otherwise she will kick my but  ;D

As MagnetoSound said:
"Sad lack of balls in today's bands, IMO"

Indecline

Re: Monitor Controller
« Reply #12 on: August 22, 2014, 04:00:14 PM »
Stunning and well done!!

ctrl+z

Re: Monitor Controller
« Reply #13 on: August 24, 2014, 06:13:16 AM »
Great! I am getting one.
+1 for a basic (level/dim/mute) wired remote.



mbjr

Re: Monitor Controller
« Reply #14 on: August 27, 2014, 01:07:43 PM »
I'm +1 with Ctrl+Z on a remote with basic functions.
Looking forward to it.

Re: Monitor Controller
« Reply #15 on: August 29, 2014, 04:31:50 PM »
I'm +2 on a remote!

AlexKP

Re: Monitor Controller
« Reply #16 on: August 31, 2014, 03:46:01 AM »
Interested! A remote would be great too...

Touf

Re: Monitor Controller
« Reply #17 on: September 03, 2014, 04:31:12 PM »
What about digital inputs ?

ruairioflaherty

Re: Monitor Controller
« Reply #18 on: September 04, 2014, 12:48:26 AM »
What about digital inputs ?

Hardly a trivial addition.  Designing good converters is a specialist business.

kante1603

Re: Monitor Controller
« Reply #19 on: September 04, 2014, 04:23:35 AM »
Hardly a trivial addition.  Designing good converters is a specialist business.
Accurately what I wanted to say.
You can always add an external D/A converter if you need it,the choice is up to you (.....and your wallet...).

Best,

Udo.