SIXTYNINER

Spl Masterbay - How It Works ?
« on: July 20, 2009, 01:58:17 PM »
Hi guys
looking for infos about Spl masterbay
http://www.spl.info/index.php?id=91&0=&L=1
mastering patchbay with remote control
ok i understand : by relays switches.........And a cpu....
but when you invert the sequence of external eq, comp,.......processors loop
and you save in a memory preset , then you can recall by pushing a button
and:1-3-2 become 2-1-3......or 3-2-1

how it do this?

any schematics , and tech info
are wellcome
thanks in advance
6T9R
>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share


12afael

Re: Spl Masterbay - How It Works ?
« Reply #1 on: July 20, 2009, 11:35:22 PM »
heavy metal is the law!!!

Skylar

Re: Spl Masterbay - How It Works ?
« Reply #2 on: July 21, 2009, 02:49:26 PM »
Here's how I assume it all works, but I could be wrong:



It looks to me that it chains 8 stereo devices together in any order, allowing you to store 3 presets.
(there's also a larger version that chains 8 8-channel devices)


So, let's say you have 8 devices connected as follows:
device 1) Neve preamp
device 2) Neve EQ
device 3) V72 preamp
device 4) API preamp
device 5) API EQ
device 6) 1176 comp
device 7) LA-2A comp
device 8) Pultec EQ

[I wish this was my rack!]


You store this chain as preset 1:
V72 preamp
Pultec EQ
LA-2A comp

"Classic" flavor


You store this chain as preset 2:
Neve preamp
Neve EQ
1176 comp

"British" flavor


You store this chain as preset 3:
API preamp
API EQ
1176 comp

"American" flavor



Now you can switch between these chains with the press of a button...pretty cool! Great for A/B-ing.
Internally, the Masterbay is re-routing the chain of your original devices like so:

preset 1:
[Device 3]

[Device 8]

[Device 7]


preset 2:
[Device 1]

[Device 2]

[Device 6]


preset 3:
[Device 4]

[Device 5]

[Device 6]





Q: So, how does it do this?
A: An assload of Relays and a Microcontroller.


Essentially, any device's input can be connected to any device's output.
The relays are probably connected in a tiered fashion to allow this.



You can think of each tier of relays as a bit in a digital system.
If a "bit" is zero, the relay follows its Normally Closed path.
If a "bit" is one, the relay is given 5V and is switched to its Normally Open path.

In the example above, you can see that to route the input to the 2nd output, only one relay needs 5V (top tier, left-most relay).

To assign IN1 to OUT3, you use "010"
To assign IN1 to OUT7, you use "110"

and so on.

This is pretty much the basis of all binary digital systems.


To implement this with a microcontroller, you would use the General Purpose I/O pins (GPIO) configured as outputs to trigger the relays.
You could connect a single GPIO pin per relay.
When you set a pin high in your code, you get 5V out of the pin, flipping the relay to which it's connected.
Set the pin low, and the relay reverts to its default state (NC).


The above diagram represents one balanced mono channel.
If you're doing 8 balanced stereo ins & 8 balanced stereo outs, the number of relays (and thus GPIO pins) needed quickly multiplies.

You'd need 7x2x8=112 relays and GPIO pins.



Now the plot thickens.

Most microcontrollers only have 20–30 GPIO pins (some have more though), so you would probably have to use multiplexers in order to handle all 112 relays.
Analog Devices makes some 1:16 MUXes that would allow you to essentially multiply your I/O.
You need 4 I/O pins per MUX to do the MUX switching.

So, consider a microcontroller, such as the Atmel ATmega325P.

This guy has 54 I/O pins.
Assuming we can use 48 of them (some pins will have a dual-purpose such as oscillator input, etc. & we can't use them):
Using 1:16 MUXes, we can expand our I/O to control a total of about 147 relays.
(5 pins per MUX, 9 MUXes = 45 microcontroller pins used. 9 MUXes x 16 = 144 + the 3 remaining microcontroller pins = 147 relays | I/O pins)

The code would be slightly more complex due to all of the MUXes, but not really too bad.




Now, let's think about the maximum amount of relays that will be sucking 5V/?A at any given time.
IN1>OUT1 = 000
IN2>OUT2 = 001
IN3>OUT3 = 010
IN4>OUT4 = 011
IN5>OUT5 = 100
IN6>OUT6 = 101
IN7>OUT7 = 110
IN8>OUT8 = 111

Any other config will be activating the same amount of relays, as we would set a rule that no two inputs could be assigned the same output.

That's 12 relays per mono channel x 2 = 24 relays needing power at any give time.

You're going to want relays that don't take much current to flip.
Here's an "ultra-sensitive" device that needs 30mA to trigger:
http://www.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMs3UE%252bXNiFaVDVuZJnAgzXjZnSFmYYYj4s%3d

24x30mA = 0.72A needed to trip the relays at any give moment.



Maybe this clarifies things?



 
« Last Edit: July 21, 2009, 03:03:27 PM by Skylar »

Matthew Jacobs

Re: Spl Masterbay - How It Works ?
« Reply #3 on: July 21, 2009, 03:05:04 PM »
Skylar... Excellent explanation.

Nice!!!!

I can get my head around this now that you've explained it.

I didn't know you could use pre-amps in the mastering chain? I guess one has to put a resistive pad on the input to drop the level. Does it really color the sound without adding to much noise?

Do you think this is a good DIY project or is there a simpler way of doing the same thing?
Also, I guess a similar system could be used in a desk to control the routing, just like the SSL Matrix right?

J

SSLtech

Re: Spl Masterbay - How It Works ?
« Reply #4 on: July 21, 2009, 03:44:30 PM »
one word answer:

matrix.

 ;D
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

Skylar

Re: Spl Masterbay - How It Works ?
« Reply #5 on: July 21, 2009, 06:04:51 PM »
Yes, it could be done with much fewer parts using multiplexers or crosspoint switch (matrix) ICs, such as this one, instead of relays:
http://www.analog.com/en/switchesmultiplexers/analog-crosspoint-switches/ad8113/products/product.html
This guy is $30 a pop in small quantity.
By the way, these ICs are essentially a ton of switches (or relays) all on a tiny piece of silicon.


But then we no longer have a passive signal path, and we have to worry about crosstalk and possibly other audio performance characteristics.
Also, we would probably want to use balanced line receivers and drivers to reduce the number of matrix ICs needed.


Skylar... Excellent explanation.

Nice!!!!

I can get my head around this now that you've explained it.

I didn't know you could use pre-amps in the mastering chain? I guess one has to put a resistive pad on the input to drop the level. Does it really color the sound without adding to much noise?

Do you think this is a good DIY project or is there a simpler way of doing the same thing?
Also, I guess a similar system could be used in a desk to control the routing, just like the SSL Matrix right?

J

I think the SPL device is targeted toward mastering, but I used a tracking example for simplicity.

SIXTYNINER

Re: Spl Masterbay - How It Works ?
« Reply #6 on: July 22, 2009, 04:02:45 AM »
....we have to stay in "discrete" way
as Manley , JLM ......
6T9R
>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share

tmuikku

Re: Spl Masterbay - How It Works ?
« Reply #7 on: July 22, 2009, 07:08:50 AM »
Don't know how many of you have seen this but aarontcramer at TapeOp board posted his DIY version of digitally contolled patchbay that has 32 I/O  8)

http://messageboard.tapeop.com/viewtopic.php?t=65179

SIXTYNINER

Re: Spl Masterbay - How It Works ?
« Reply #8 on: July 22, 2009, 08:01:47 AM »
Don't know how many of you have seen this but aarontcramer at TapeOp board posted his DIY version of digitally contolled patchbay that has 32 I/O  8)

http://messageboard.tapeop.com/viewtopic.php?t=65179
hi
thanks for post
it is a nice diy project , expecially the soft touch screen....
but computer flat cable and "ics" really not good for sound ,
overall for mastering sound,
cheers
6T9R

>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share

radiance

Re: Spl Masterbay - How It Works ?
« Reply #9 on: July 22, 2009, 08:17:21 AM »

but computer flat cable and "ics" really not good for sound ,
overall for mastering sound,

Although the builder can't hear the difference I'm still curious on how those tests turn out....recording a track through the device and flipping the polarity to see what the cancelation is when played together with the original track...

"Knowing that you are dreaming, however, does not automatically guarantee full rationality.
Then again, being awake doesn't ensure good thinking, either." -  Lynne Levitan


SIXTYNINER

Re: Spl Masterbay - How It Works ?
« Reply #10 on: July 22, 2009, 06:42:38 PM »
but computer flat cable and "ics" really not good for sound ,
overall for mastering sound,
Although the builder can't hear the difference I'm still curious on how those tests turn out....recording a track through the device and flipping the polarity to see what the cancelation is when played together with the original track...

........try record a Yamaha C7 with:
neumann U47 with original tube + millennia or GML mic preamp + Prism sound "stereo" (not 8ch)
ada converters , and then put the tracks on a manley or GML or Weiss EQ ,
then on a pair of genelec 1031A or 1032A
after this
try the same record , but starting from a Behringer or Sm pro audio or M-Audio......ecc.......
then compare the tracks
let me know the differences about
cheers
6T9R

ps
also take a nice mic as Neumann U87 or the best U47
with fiew mic/line cable type , like: Mogami , Klozt m5000 ,Canare.......
and compare with low cost cable like tasker , belden (yes belden), ecc.....
 ;)

----------------------------------------
Suggestion
Before say : Sound Great
compare it , with the best "tools" in the market/around
« Last Edit: July 22, 2009, 06:46:14 PM by SIXTYNINER »
>>" 1 Picture say what billions words cannot "<< - >>"SMD Kill the DIY STAR"<<
Why in the  forum  if no share

radiance

Re: Spl Masterbay - How It Works ?
« Reply #11 on: July 23, 2009, 04:52:05 AM »
yeah, well...I sort of get your point. But I'm still curious on how those tests turn out... ;)

EDIT: and that's not your test but the test from the builder of the matrix I'm talking about...
« Last Edit: July 23, 2009, 04:55:00 AM by radiance »
"Knowing that you are dreaming, however, does not automatically guarantee full rationality.
Then again, being awake doesn't ensure good thinking, either." -  Lynne Levitan


 

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