Mastering console

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Don't see why not. I understand that quite a few are built to order or otherwise one-off sort of things.

Are you integrating specific existing gear into your setup? How are you setting it up? Remember, most devices are unbalanced inside, but unbalance at the input and re-balance at the output. You can either go the full nine yards and have a fully balanced signal bath, or very careful setup an unbalanced path - with care, they can be quite clean and unproblematic.

What kind of MS matrixing do people use in these, an active one or transformer split passive?

Bear
 
I haven't been able to find anything on what sort of MS Matrix companies are using in these. I would guess passive.

I think this could be done. I'm going to start doing some research and post some links to mastering consoles soon.

I hope some people find this interesting and get involved with some input!

Thanks,
Aaron
 
i'm interested! I built the PRR vari-mu and like it a lot. I would definately use it as a mastering compressor. Right now I use it as the last compressor before A/D conversion into the computer. very clean and simple for very cheap..

:thumb:
 
Here are some links to mastering consoles-

http://www.spl-usa.com/indices/mastering_E.html
I really like the design SPL used on these.


http://www.jlmaudio.com/mastering%20Console.htm
New on the market, this one might be close to what I base a design around.

http://www.stellacustomelectronics.com/
I don't know much about this company, but it looks interesting a nd simple.

www.manleylabs.com/Manley_mastering.html
Manley of course offers custom mastering consoles.

http://www.crookwood.com/products/iMon-Master%201.htm
Crookwood makes some interesting products.

Any input on mastering desks?

Thanks
Aaron
 
I'm actually in the process of designing one for my major project at uni....with the possible intention of making it available as a DIY project when / if I'm done with it.

Some guys here have already built their own.

The thing is, everyone engineer wants/needs different features...some want a passive signal path, some prefer active, some like simple monitor level control, some require fine resolution (0.1dB/steps), phase, mono, things like remote control.....an insert matrix, M/S processing etc. Some will sneer at the use of IC's, some will sneer at the use of anything but passive.

If your building it for yourself, then you should already have an idea of what features you require.

How many sources will feed it, how many will it feed? How many sets of monitors do you run in your room, do you require surround capability, how many bits of processing gear do you want to incorporate via inserts. Are you going to use a patch bay etc or would you like to have an insert matrix built-in. Are you comfortable with logic and different switching methods. There are many ways to skin a cat.

Balanced vs unbalanced, are you running long lengths of cable between source, console and monitor amps? Is your room succeptible to noise and RF interference? What are you planning to add to the system, future expansion to 1/4" etc.

Capacitively coupled or servo'd, maybe even transformers in there?

Things like these influence the design decisions.

It gets very complex. If you want simple - you can't get much more simple than a passive box etc.....but there are potential gotchas when doing this. Of course if you go active, how many components/design topologies are you going to listen to to find the ultimate in transparency. Ultimately will it be as transparent as a passive design?

Things that make them expensive:

Custom miltary spec switches - the likes of Shallco, Elma, EAO etc
Research and development time.
Discrete gain blocks such as the Hardy990s etc.
High precision, low noise resistors.
Audiofile (fool) capacitors and silver cabling etc.
Lots of high quality signal relays if you go that route....you could easily spend >$200 on relays if exclusively switching signals with 'em.

As far as M/S goes, some guys like to use a good set of high headroom transformers or you can go active and build up encoder/decoder matrices, add things like stereo width control ala Dangerous Music S&M.

I think Jakob has a schematic somewhere for the transformer M/S implementation, Lundahls IIRC.

Definitely check out the manuals for the SPL stuff, gives you an idea of just how complex an active design can get.

Best of luck with whatever you do......

Cheers Tom
 
What makes these so expensive?

well there are a couple of reasons.
But mainly it's because they are made as one off's by hand i.e. custom made one at a time for each mastering studio using only the best in audio parts usually by hand and not from an assembly line. They are often built to higher standard and usually use stepped pots Vs a standard linear pot that is not stepped. That alone often makes them more expensive. I think They also use military grade switching which last 100 times longer then a normal switch.

If you really want to check out a cool mastering console I present the masterpiece designed by rupert neve.
http://www.legendaryaudio.com/
 
JLM's modular approach is cool idea and allows for future expansion.

He seems to have custom IC's....but I would expect Joe's forthcoming 99S gain block to be a contender for an active system when it arrives. Especially for the high headroom (if of course you need it...?).

Here's a brief outline for a balanced in/out active system.

Burr-Brown INA134/7 line receivers, unbalanced inside the box. OPA134 based active M/S matrix....PGA2310 active stereo volume control (0.5dB steps) driven via PIC micro, DRV134 line drivers. Passive switching on rotaries or relays, balanced via the same BB chips above or left unbalanced for inserts and speaker/meter outs etc

You could replace the receivers / drivers with the new THAT InGenius / OutSmarts if they're available. Analog Devices have the SSM series too.

No idea how that will sound, its all in the design but thats a possible direction and similar to the Dangerous Music gear.

Cheers Tom
 
Tom I like your signal chain thus far. Could you further explain the PIC mirco? I see there are a lot of books and info on them, but personally I don't know anything about them.

Aaron
 
Small microprocessor to control the PGA2310 and/or relays for source switching. PGA is driven via SPI (serial peripheral interface) to set volume. 8-bits, 0-255 volume steps in 0.5dB.

I have briefly listened to my PGA evaluation board and it sounds quite nice, but I need to do more critical listening/analysis, its not what I have planned for my design tho, as mine should be predominantly passive....with some Forssell992s.

The above was just something I considered. It would however be a relatively cheap way to do a console. FWIW, I'm pretty certain the PGA2310 is the chip used in the new Grace Design m904/906 monitor controllers.

There are other ways to control the chip, you're not limited to the PIC Micro. One cool idea I considered was a remote controlled box with a PC front-end interface controlled via USB or Serial. However, its a bit beyond a oneman job in the time scale I have......

The BB signal path may be pretty cool, you could of course add an analogue passive attenuator for level control instead of the PGA if you don't want to play about writing software in C or ASM.

So what features do you need/want? And do you prefer passive or active implementation?

Cheers Tom
 
Hey,

I was wondering about using those PGA chips in a regular mixer design for level control as well as in a monitoring box. Pilo has implemented the 4 chan version (PGA4311) with MIOS (www.ucapps.de) which uses a PIC 'core' and allows you to control the PGA chip via say an encoder, motorfader, regular pot etc...works well I hear...
 
Hey DaArry!

I've been checking out the MIOS stuff but I'm having a hard time navigating their website....

Do you happen to have a link to their implementation of the PGA4311?

Tom
 
Hey Tom,

U aint the 1st to say that! There isnt mention of the PGA/MIOS combo on the main ucapps site as it was just one chap (Pilo) who made a post in the midibox forum about implementing it a while back...

Here's some info from one of the threads: http://70.84.40.25/forum/index.php?topic=2165.0

I'm sure he'll post here shortly if need be...

On another note regarding these PGA chips - do you know - if they where used for level control on a mixer channel say, is it correct to assume a (what would be there otherwise - if a regular fader pot was used) 'fader booster' ckt wouldn't be needed as the PGA has gain 'on-chip' already...so you'd just go from the pga chip to the group selector/summing buss?

Cheers!
 
Thank for the link bud!

They should not require a fader booster as they have an opamp onboard. Apparently it is similar in design to the OPA134.....its an inverting opamp stage that is used to change volume.

However, there is something in the datasheets (can't remember off hand) but I think you'll need to run the device into an impedance way above 600ohms otherwise THD starts to rise. So your buss impedance is going to have to be high I think - possibly not a good idea when it comes to crosstalk. You may have to isolate the PGA output with another opamp if you need a low buss impedance. I think thats how it will may need to work, not really a fader booster but a buffer to keep distortion low.

Sounds a bit like Igors box with remote faders.

You'll want to use the PGA2310 for added headroom I expect as well (the only one on 15V rails)?

I think I smell what you've got cooking - I had the idea a while ago......

Analogue mixer with MIDI automation?

Thats a cool project. I was thinking....logic, PT or SX automation to a MIDI output, total recall and fades in 0.5dB steps........cheap 'flying faders'!!!!!

You could use your MIDIbox faders to control the PGAs in the mixer.....faderless remote controlled summing mixer with software recall and automation...fook me the possibilities are endless wth that one!

Cheers Tom

:thumb:
 
Oh yeah, you'll get about 31dB gain outta the PGA2310 as well, so its good to go for line inputs.....

INA134/7 on the front of it and you'd have a nice balanced in mixer channel.
 
I think I smell what you've got cooking - I had the idea a while ago...... Analogue mixer with MIDI automation?

Indeed ;) glad we're on the same page here!! :thumb:

The idea was to also keep some elements to control the seq (logic in this case) so it'd be a hybrid logic control/analog mixer...I'm thinking the vpots, channel buttons, scrubb section etc...all this is handled under MIOS already...

Gonna get cracking on the analog/pga side of things and post up some ckt designs...

Cheers!

Oh yeah, you'll get about 31dB gain outta the PGA2310 as well, so its good to go for line inputs.....

INA134/7 on the front of it and you'd have a nice balanced in mixer channel.

Great - yes I was aiming to roll with those INA/DRV chips for inputs n inserts too...
 
daArry's going for a DIY SSL AWS900!!!! :shock: :green:

Sounds like one hell of a project. You be putting EQ's and whatnot into the channels?

BTW there is another chip out there made by a Scottish company, Wolfson Micro, its a similar idea to the PGA2310 but you can pick the inverting opamp of the outputs. That way you'd have a touch more control over the sonics.....I think its called the WM8816

I was wondering about that in conjuntion with something discrete such as the Forssells....anyone want to chime in?

There must be plenty o'negatives when adjusting the gain on such a device in inverting mode?

Tom
 
hehe, well it may not be pretty or feature packed as the AWS :grin:

EQ would be an option ye (been thinking of various ideas for that from NYD's passive to butta's Nemek) - but atm, just a basic mixer config is needed...

RE: that wolfson chip - yup spotted that and thought as you did that having the option for setting the output (with say a DOA) would be coo but I read somewhere (think it was diyaudio forum) that the PGA was an overall better option...aint tried either tho so I dunno...

Would a simple jfet buffer be adequate for the 2310 d'ya think btw?

Peesh!
 
Hi there!
Burr-Brown INA134/7 line receivers, unbalanced inside the box. OPA134 based active M/S matrix....PGA2310 active stereo volume control (0.5dB steps) driven via PIC micro, DRV134 line drivers. Passive switching on rotaries or relays, balanced via the same BB chips above or left unbalanced for inserts and speaker/meter outs etc

You could replace the receivers / drivers with the new THAT InGenius / OutSmarts if they're available. Analog Devices have the SSM series too.

No idea how that will sound, its all in the design but thats a possible direction and similar to the Dangerous Music gear.
'cuzz me.
Are you building MASTERING console or Dangerous stuff???
I opened one custom Crookwood. It is not mastering console
(for my snabby minds about mastering console) :).
Same cheap design.
Maybe once I will finish with 600 Ohm h-pad relay (gold teledyne
of course) attenators 0.3db/step, all routing on Leach aero stuff relays,
those freaky violet 0.1% resistors, teflon silver wire
and m-s trafos on huge 80% Ni & etc, I not just talkin'-
as well I have some resourses for this stuff.
For guys who _talking_ here about mastering consoles:
I heard the sound of some cheap mastering rooms and some what you call auudiophoolish setups. Last ones sometimes were much more clean
and suitable for mastering.
Cheap stuff for mastering room?
Well, another g1176. Working...
 
[quote author="daArry"]EQ would be an option ye (been thinking of various ideas for that from NYD's passive to butta's Nemek) - but atm, just a basic mixer config is needed...[/quote]

Jakobs' Calrec is an option too....

Would a simple jfet buffer be adequate for the 2310 d'ya think btw?

For an output buffer? I would guess so, AFAIK anything that offers a high input impedance will prevent the THD from rising in the PGA. Jfets are high input Z(?) so I guess that would be a simple solution instead of a fully-blown opamp.....dunno.

[quote author="ijr"]'cuzz me.
Are you building MASTERING console or Dangerous stuff???
I opened one custom Crookwood. It is not mastering console
(for my snabby minds about mastering console) :).
Same cheap design.
Maybe once I will finish with 600 Ohm h-pad relay (gold teledyne
of course) attenators 0.3db/step, all routing on Leach aero stuff relays,
those freaky violet 0.1% resistors, teflon silver wire
and m-s trafos on huge 80% Ni & etc, I not just talkin'-
as well I have some resourses for this stuff.
For guys who _talking_ here about mastering consoles:
I heard the sound of some cheap mastering rooms and some what you call auudiophoolish setups. Last ones sometimes were much more clean
and suitable for mastering.
Cheap stuff for mastering room?
Well, another g1176. Working...[/quote]

Hey Igor!

Any pics from the inside of that Crookwood? - it it similar in design to the Dangerous stuff?

I'm not building anything like the above......that was just a "cheap-ish" suggestion for the sake of the discussion.

Mine is shaping up to be similar to your suggestion, yet not so esoteric.

All relay switched, passive process path, fully balanced, 4 inserts, 2k5 bridged-H process output trims on Greyhill rotary switches (10dB attenuation).
Relay switched passive monitor path, relay controlled (8 stage-cascaded) bridged-H level attenuator, 0 to -63.75dB in 0.25 steps. 0.5% metal films etc. Level memories/trims for source selection via PIC Micro. I'm thinking of ways to reduce the number of resistors in the signal path of the monitor attenuator. At the moment it is 8 per stage when fully balanced......I'm worried about noise,as thats 64 resistors in max attenuation. Any advice? Maybe O-attenuators instead, cutting it to 32?

Optional Forssell992/3 differential output stage for line driving unbalanced or balanced input power amps. Can be removed if running fully balanced room.

Headphone amp probably based around OPA627 etc and a pair of 5532/4 buffered meter outputs for VU etc. I hope I will get around to actually making this thing a reality in the next three months....no more talking! ;-)

It seems you get all the cool surplus out in israel!

Cheers Tom
 
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