Transfer Console build

[morls]

I’ve been putting together some boards from ka-electronics to assemble a mastering transfer console. It’s taking shape now so I thought I’d post a pic or two as things come together.

Planned signal path is:
Stereo in - gain - HP filter - MS Encoder (bypass-able) - 4 stereo inserts with flip between 1+2/3+4 - width control and tilt EQ - MS Decoder - 4 stereo inserts with flip - main out to ADC, monitor out with source selector 1) main out; 2) post preamp/pre ADC; or 3) DAW out

I’m still working on layout and wiring, but here’s where I’m up to…

Stephen

 

[Sinkia]

wow

 

[Gold]

Looks good! If you have never used the DIN rail terminal blocks you should terminate the wires with ferrules. McMaster-Carr

 

[morls]

Thanks for the link, I'll check these out. I haven't used DIN blocks before, but I really like them

 

[Fsharpminor]

DAMN!! NICE!

 

[morls]

I'm having second thoughts about the output and monitoring section, and any advice would be very welcome. Here's my current plan:



The idea is to take a mult from the output of the insert chain, one direct to ADC (main out) and one for monitoring. The monitoring path is to a switching board, giving me 3 options for monitoring: main out and 2 other sources via XLR input (most likely post-preamp/pre-ADC and post-DAW).

The main out and monitor out are then fed into a balanced output stage with 2 parallel paths, one to ADC and one to a Goldpoint stereo stepped attenuator and then monitors. The inputs to this stage are THAT 1246 ICs, bridged straight to the outputs, THAT 1646 ICs. My original thinking was that I'd need to drive the output from the console, and that this would be a very clean option.

I'm now wondering if this balanced output stage is necessary? If I omit the output stage, the last item in the insert chain will be driving both the ADC and the attenuator/monitors.

Another option is to feed the ADC straight from the insert chain, and use the output stage for monitoring only.

 

[Unit-8]

Wayne is a great person and really competent, thanks to his boards and his precious advice I made my MTC.
This is what I got.

 

[Gold]

I'm having second thoughts about the output and monitoring section, and any advice would be very welcome. Here's my current plan:

View attachment 88689
I'm now wondering if this balanced output stage is necessary? If I omit the output stage, the last item in the insert chain will be driving both the ADC and the attenuator/monitors.

Another option is to feed the ADC straight from the insert chain, and use the output stage for monitoring only.

Either way seems fine to me. I would lean towards the dedicated amplifier if the insert chain is likely to change. I’d want the same amplifier feeding the ADC and monitor in all cases. If the order of the insert chain is fixed I’d skip the extra amplifier.

 

[morls]

Wayne is a great person and really competent, thanks to his boards and his precious advice I made my MTC.
This is what I got.

Wow, that looks great! It's always good to see other layouts. Your case and layout of controls looks good, I'm still figuring out my own layout. I doubt my wiring will be as neat as yours!

Wayne has been a huge help to me as well, I thought I'd post here so I don't take up too much of his time with general questions...

What switches did you use for the tilt eq and width?

Either way seems fine to me. I would lean towards the dedicated amplifier if the insert chain is likely to change. I’d want the same amplifier feeding the ADC and monitor in all cases. If the order of the insert chain is fixed I’d skip the extra amplifier.

Thanks. The insert chain will be flexible so I might keep the output amplifier.

 

[Unit-8]

Hi Morls, the switches I have used on most of the MTC controls are the Elma A4, except those for the cutoff filters which are 2 Grayhill 71 series.

 

[morls]

Thanks. I was thinking of a stereo goldpoint for the main attenuator, but USPS charge $70 USD shipping, which is over $100AUD!
The elmas look very good too, so no dramas

 

[Unit-8]

The Goldpoint are derived from the Elma, if you look closely they are identical. The only difference is the PCBs soldered on them made by Goldpoint. If, on the other hand, by "main attenuators" you mean the 2 switches that control the input gain, they are 24 positions, 1 deck, 1 pole. You don't need 2 deck ones, unless you want to use a single knob for both channels. However, it is better to have separate controls if there are level differences between the two input channels. The choice is yours, of course.

 

[morls]

Sorry, wasn’t clear there. Yes, I’m using single channel gain controls for the inputs. The stereo attenuator is for my monitoring output.

 

[Slime_Lord]

Wayne is a great person and really competent, thanks to his boards and his precious advice I made my MTC.
This is what I got.

Wow, that looks outstanding! I’m finishing my MTC up this week and am now questioning my front panel after seeing yours .

I’m still a bit confused on how the MSII should be configured. It seems that the majority of builders have installed it onto an insert point. Is there an advantage to this?

the way that I’ve been using mid/side with my patchbay is encoding before hitting the outboard chain then decoding on the return in. I was originally going to go from the outputs of the IGFO, into the encode input of the MSII, encode out to the inserts, insert outputs into the decode inputs, decode outputs to the output feeding the A/D to achieve this but am wondering what the advantage is to running it on an insert instead?

 

[Unit-8]

Hi Slime_Lord,

This is my configuration: IGFO > Insert 1/2 > Insert 3/4 > Insert 5/6 > MSII > EEQ > DAC Out||Monitor Controller IN||VU Buffer.
Your setup is probably different, but the path to follow is the same through the modules/boards used.
As for the pros or cons, you don't have to think this way.
It's just the way to act on the signal flow path.
In this case, having the MS inserts on the rear panel gives you the ability to use dedicated outboards in addition to those you would normally connect on the inserts.

 

[morls]

I’ve soldered the resistors onto the first Elma switch to be used on the MS board, for the Tilt EQ. I’ll do another for the width.
I’m confused as to how these are wired though. Here’s a description from the proaudiodesignforum:

The Width control is grounded so you should use 2C+S and ground the shield at both ends to carry the grounded CCW terminal.

The Tilt requires all three pins to float with an overall electrostatic shield. Ground the shield only at one end. The shield should not be connected to one of the pot's terminals. There isn't a Phoenix terminal for the shield so use "G" ground pad.

I’ll
attach some pics as well, if anyone can help I’d be very grateful. I’m not sure where to make connections at the switch end…

Cheers
Stephen

 

[morls]

After more thought, I'm wondering if the wiring (for the width switch) is as follows:

CCW to solder tab 2 (stop screw in opening 1)
CW to solder tab 22 (stop screw in opening 23)
W to large solder tab inside outer ring of resistors

 

[Gold]

On the schematic CW, CCW and W are labeled. Am I missing something? CW is the input top of the string. CCW is the bottom of the string. W is the output.

 

[morls]

You’re not missing anything, I’m just looking to confirm which pins I connect to on the switch itself.

 

[Gold]

You’re not missing anything, I’m just looking to confirm which pins I connect to on the switch itself.

CW and CCW could be reversed without any problems. It depends on whether you want Mono to be when you turn the knob CW or CCW. CW and CCW are the ends of the resistor string. If you measure the resistor string it should be the total value unaffected by turning the knob. The Wiper is the Output and will change values as it moves up and down the resistor string.