Split/Inline or something different

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moamps

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It is a momentary push button. The logic circuit behind is on the picture.
The global switch can be single (with a small logic circuit which I can draw tomorrow) or just two momentary switches which provide power voltage via small resistors to two control buses.
 

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ruffrecords

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moamps said:
It is a momentary push button. The logic circuit behind is on the picture.
The global switch can be single (with a small logic circuit which I can draw tomorrow) or just two momentary switches which provide power voltage via small resistors to two control buses.
OK so the schmitt debounces the push button and clocks the D-type which is wired to divide by two so it simply toggles on each button  press so the channel flips to the opposite state to what is was. R104/C2 ensure all D-types are reset at power up. Otherwise state is set by global S or R.

This means whenever you operate a global, all channels go to this state regardless of their prior state. I am not sure I want this which is why I think my channels have three states not two. Need to think about this.

Cheers

Ian
 

jim-analog

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Greetings,

Hi Ian, great work on continuing the development of the tube console!

  One of the consoles I take care of is a somewhat large Neotek (model S3-C) 32 x32, essentially an inline.  But with a primitive digital logic portion in the master section that has the ability to globally switch between 3 modes; track, overdub or mix. A 2 bit logic bus goes to each channel strip where a bunch of FETs set up the circuitry connections for the different modes.  The selections between mic/line, monitor pot/fader, metering point and channel outputs are then set all at once from the 3 switches at the master section.

I can post a block diagram of the switching if that would be of any help, as I can't see the entire structure in my head right now. 

Going 100% the opposite direction, for my personal room (recording to tape, essentially one "live" input at any given time), I was working on the idea of *everything* being manually patch-able.  So, you could configure the console to input any mic, line or tape return to any input/output/metering/etc, EQs float where ever you  want them, faders get patched to where they need to be, on and on.  Signal path could be from absolutely minimum to as complex as required. Think exactly like an old, fully modular, analog synth (which was my inspiration). I can sort of see this type of thinking with some 500 racks and minimal control surfaces being a "light version" of the idea.

  I know that would never work for a commercial facility where speed and repeatability are so important or with a large scale console where it would be an absolute nightmare of patch cables, but for a smaller console/ "one man band" personal studio it does provide maximum flexibility and essentially makes the console/processing gear part of the instrumentation.

  Perhaps with low'ish channel count, your high end quality tube mixer could be set up in this "fully modular" fashion. Just a thought that may appeal to a certain type of client.

Please let me know if you'd like any of the Neotek docs, I don't think they were very common in the UK.  Keep up the great work, it's really cool to follow.

Regards, Jim
 

Matt C

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Ian, I modified my console to have an arrangement similar to (but very simplified) what you describe. Mine just uses a two position toggle switch.

In one position, the direct out is fed from the mic preamp, and the tape return is fed to the EQ and then the channel fader. 

In the other position the direct out comes from the output of the EQ, and the tape return is sent straight to the channel fader.

This way the faders are always controlling the tape return and there's little/no changeover between tracking and mixing. I love working this way and to me it makes the other common mixer architectures look insanely cumbersome.  The only awkward part of my setup is that it doesn't have your center "normal" position, so to get the mic preamp signal to go directly through the channel fader and into the groups, you need to patch it through the patchbay.  But I rarely do that so no big deal for me.
 

boji

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So where in these paths does the EQ appear?
Was afraid you would ask that.  :-\
No buttons pressed it goes straight to patch.
Typically during mix if [Slot 2 Insert] is active it's placed after A1 which is receiving line input. The EQ drives the fader like the old API consoles. However, if only [Slot 2 On] is active, it puts the EQ directly after Slot 1 micpre (tracking).
If both are pressed it is placed after Slot 1 or tape return depending on Slot 1 activation. EQ drives fader with A1 excluded to patch.

Do you have an input transformer as well? I seem to remember API uses input transformers as well as output.
No, not at present. Line in is going directly to A1 or Slot 2 for now.  Input TX's are only on Slot 1 pre's.

moamps:  It is a momentary push button. The logic circuit behind is on the picture.
Nice instructive toggle circuit, thanks for posting
 

ruffrecords

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Matt C said:
Ian, I modified my console to have an arrangement similar to (but very simplified) what you describe. Mine just uses a two position toggle switch.

In one position, the direct out is fed from the mic preamp, and the tape return is fed to the EQ and then the channel fader. 

In the other position the direct out comes from the output of the EQ, and the tape return is sent straight to the channel fader.

This way the faders are always controlling the tape return and there's little/no changeover between tracking and mixing. I love working this way and to me it makes the other common mixer architectures look insanely cumbersome.  The only awkward part of my setup is that it doesn't have your center "normal" position, so to get the mic preamp signal to go directly through the channel fader and into the groups, you need to patch it through the patchbay.  But I rarely do that so no big deal for me.

Thanks for that Matt. I agree with your comments about common mixer architectures! That is an interesting way of working. I guess you rely on the tape return being fed from the tape in when the track is in record?

Cheers

Ian
 

Matt C

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ruffrecords said:
That is an interesting way of working. I guess you rely on the tape return being fed from the tape in when the track is in record?
Yes, basically the recorder is permanently in the insert loop.  Not a practical solution for a mixer being sold to the general public, but for my own personal use it's great. I think I originally got the idea from Steve Albini/Electrical Audio. They have a modified Neotek console that's setup up in a similar way to what we're talking about.

When I was making the modification I was hoping to find a 3 position rotary switch in order to allow for a "normal" feed through option, but I couldn't find a good option for a 3P3T switch that would fit inside the channel strip.
 

pvision

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Global status switch plus a local channel status invert switch. If you make the latter non-latching you could have a master reset so you don't have to go looking for inverted channels when resetting the board

Nick Froome
 

ruffrecords

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pvision said:
Global status switch plus a local channel status invert switch. If you make the latter non-latching you could have a master reset so you don't have to go looking for inverted channels when resetting the board

Nick Froome

We are beginning to get into the intricacies of individual working practices. When you switch to mix down there will most likely be a number of channels you don't want to flip because you are using them as FX returns for example. So you would switch these to the third position to ignore remix requests and leave then there. You probably do not want them resetting every time you operate the global button because you would have to go and set them again. I am generally against reset buttons because  there is no undo. It only takes one idiot to say "what's this button for"...

Having said that, it is not to hard to implement either from of logic according to the customers needs/desires.

Cheers

Ian
 

PRR

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> *everything* being manually patch-able.

That requires "a brain", which may be in short supply, especially after 13 hour days all week.

Also a darn LOT of jacks. Which are not cheap!

It really gets to the point that we want "everything to everything" routing, and an AI to listen to the mix-operator and figure out the connections.
 

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ruffrecords

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PRR said:
> *everything* being manually patch-able.

That requires "a brain", which may be in short supply, especially after 13 hour days all week.

Also a darn LOT of jacks. Which are not cheap!

It really gets to the point that we want "everything to everything" routing, and an AI to listen to the mix-operator and figure out the connections.
I cannot find the picture but I think Helios had this 'pegged' back in the 70s. They used a kind of mini peg board with inputs on one axis and outputs on the other. You just inserted a peg where the output you wanted met the input you wanted it to go to. Very visual, reasonably intuitive and no trailing patch cords.

Cheers

Ian
 

Brian Roth

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After trying to follow all the different directions on this thread, I'm going back to "basics",

IMO, there are two distinct signal paths required when doing multitrack projects with an analog  mixer , regardless if the multitrack is Old School analog tape or newer DAW. 

You need to get the mics (or line signals from synths, etc) into the "recorder", and you also need a method to create control room and headphone cue mix(es).

That implies either a "split" mixdown section, or an intelligent "inline" signal flow.  Either method requires separate level controls:

1.  Tweak the source  level to the recorder.

2.  An independent mix for CR mix and cue.

One of the intelligent inline designs I encountered that wasn't totally confusing to use was the MCI JH-600 desk.  It had various flip and flop switches, but in "native" mode it operated like this:

1.  The slidewire fader was fed from tape recorder's output.  Channel EQ normally was in that path.  Then , that path fed the panpot for CR mix and also the echo and cue send pots.  This mode of operation relied upon the multitrack to do automatic switching from sync playback to input monitoring when doing punch-ins.

2.  A rotary level pot adjusted the level from the internal mic pre (or line input) and was routed to the multitrack buses.  A variant that I did when I built a 24 track desk (back in the 1970's) was to have a "Direct" switch which selected the channel signal vs. the bus feed.

I can elaborate more if anyone is interested in that particular workflow.  Keep in mind, a few switches on each channel could flip various functions (ie, EQ into recording path vs monitor, etc)

Edit: added a link to a rather incomplete description of my M77 desk:

http://brianroth.com/projects/m77/m77.html

Bri


 

Matt C

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Brian Roth said:
2.  A rotary level pot adjusted the level from the internal mic pre (or line input) and was routed to the multitrack buses.  A variant that I did when I built a 24 track desk (back in the 1970's) was to have a "Direct" switch which selected the channel signal vs. the bus feed.
There's one thing I wonder about when implementing a design like this.  I see a big opportunity for creating feedback loops using the buses.  If we group a couple tracks through a bus and send it to a track on tape, then it gets returned to a separate fader, does anything prevent that tape return signal from being routed to the same source bus, making a feedback loop? Are the buses somehow kept separate in a way I'm not seeing? The way I configured my console I just have to be careful, but I very rarely use buses to group tracks to tape so it's not a big issue for me.
 

ruffrecords

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Matt C said:
There's one thing I wonder about when implementing a design like this.  I see a big opportunity for creating feedback loops using the buses.  If we group a couple tracks through a bus and send it to a track on tape, then it gets returned to a separate fader, does anything prevent that tape return signal from being routed to the same source bus, making a feedback loop? Are the buses somehow kept separate in a way I'm not seeing? The way I configured my console I just have to be careful, but I very rarely use buses to group tracks to tape so it's not a big issue for me.

Basically only common sense. It is quite easy to create loops on a big  mixer. If you use a regular channel for an FX return then you  can send the return to any AUX including the one sending to the FX. It is why dedicated FX returns don't usually have the full set of AUX sends. Usually they have the pre-fader ones so the musicians can hear the FX  but no post fader ones that would be used for FX sends.

Cheers

Ian
 

ruffrecords

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@Brian Roth

Thanks for the comprehensive reply Brian. It is good to get back to basics. There is a lot you could do but this is really about what you should do in a relatively small mixer. Your thoughts run more or less parallel to my own. But you have raised an interesting point. I have the tape send after the EQ and the return pre EQ so you can use EQ both when tracking and for mix down. In your description the direct (tape send) occurs pre EQ the same as the return. This makes sense because it means you can EQ what you monitor while tracking but it does not get printed but it relies on the tape machine providing source on the return when recording (which most tape machines do but I don't know about DAWs).

Cheers

Ian
 

Brian Roth

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The jh-600 default mode was EQ in the tape return path, but they added a switch that moved the EQ into the recording path, leaving the return path flat.  When I was doing a lot of recording to 24 track tape with those desks, I used that switch quite a bit so that recorded tracks had EQ.  No perfect solution...lol!

In the past few years, I've been recording with a Neve Capricorn digital desk into the Logic DAW, and Logic can do the automatic switching between "sync playback" and "input". modes.  I use Logic just as if it was a big analog multitrack.  I'm an Olde Dawg <g> and made the equipment adapt to the workflow that I learned decades ago.  One bonus:  unlike tape, the DAW has an Undo function!

Bri


 

Brian Roth

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Matt C said:
There's one thing I wonder about when implementing a design like this.  I see a big opportunity for creating feedback loops using the buses.  If we group a couple tracks through a bus and send it to a track on tape, then it gets returned to a separate fader, does anything prevent that tape return signal from being routed to the same source bus, making a feedback loop? Are the buses somehow kept separate in a way I'm not seeing? The way I configured my console I just have to be careful, but I very rarely use buses to group tracks to tape so it's not a big issue for me.

The jh-600's normal  signal flow was such that the return through the slidewire fader went to the stereo mix bus and the aux sends.  Some alternative routing swwitch selections (via flips/flops/swaps in the signal flow) could create a feedback loop, but it wasn't a common problem.

Bri

 

zamproject

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Hello Ian and all

I think we already discuss this before for your tube console signal flow
I'm certainly biased (Studer addict) but the remix function is a nice feature for a small mixer.

Best
Zam
 

ruffrecords

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zamproject said:
Hello Ian and all

I think we already discuss this before for your tube console signal flow
I'm certainly biased (Studer addict) but the remix function is a nice feature for a small mixer.

Best
Zam

Thank you Zam. Yes we did discuss signal flow at length. Now that the Mark 3 mixer channel is starting to come together, there are a number of lose ends that need tying up and remix on small mixers is one of them.

How do you switch from tracking to remix on your Studer?

Cheers

Ian
 
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