some controls I don't get

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cardboard

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Oct 23, 2019
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Dear all,

Recently, I became interested in the REDD desks. As a designer, I see a lot of 'Germany-in-the fifties'- style in the REDD.17 desks. Aspects like:
- almost no text
- form follows function
- early 'Ergonomics', like a dedicated knob type for each function
- no stylish embellishments
- Modularität whenever possible
all really fun to discover in the .17 desk.

I have a few questions about the controls on top. Most are easy to grasp, and their relation to each other, to the inputs, amps, Siemens U-links and to the outputs are easy to grasp as well. But not all. Some, I just don't get.

I prepared a picture, where I've put in my question marks. In short:

-> on the 'top left' unit, there are 3 knobs for the 'Check' circuit. What does each of them do, and - equally important - what are they called?


I'd be delighted if you could shed some light on this.

Regards,

M.
 

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ruffrecords

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I am not certain of this but my guess about the check function is that it allows you to check the correct operation of the modules in the desk. In those days, all modules brought out test points that allowed you to check that each tube was operating correctly. I suspect this switch allows you to look at these on one of the meters.

Cheers

Ian
 

Winston OBoogie

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Hey Mart,
I don't have schematics on hand this minute, and the only ones I have with REDD.17 numbers are the ones which also relate to the REDD.37 and the REDD.51 such as measurements and modifications to the V72 and circuits pertinent to the Sum & Difference etc.
However, I can say with certainty that there is no means to check individual valve currents so these controls aren't that.
I'll see what I have that might give a clue and send you another PM. What info. did you use to determine these were indeed "check" circuits?
 

cardboard

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Hello,
In the picture of the left wing unit, the symbol that the designer (PKB) uses for 'check' circuits can be seen, as attached.

I deducted this from the REDD.M.37 Writeup, where on p.9 and 10, the controls on the left wing of the .37 are described. Elaborate Checking of a lot of signals "all without disturbing the working conditions". and looking at attached picture of that unit, again that 'Check' symbol is found, top left! Looks a bit like a slide screen pulled out half way :)

So that's what these circuits are for: checking signals. Listening in on them. We would rather call it monitoring, I guess.
And now, I'm interested in the actual function of each of these 3 rotary controls.

Mart
 

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Winston OBoogie

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Ah, I see what you mean now. Yes, "check" is what we would consider PFL or AFL. There was no PFL on each channel, rather, the channel or amp you needed to listen to was selected via a monitor select control.

I hear there is a Rossetta Stone hidden somewhere that holds the key to PKB's hieroglyphs :D


Edit: that pic you show of the 37 is an unmodified 37.
On a .51, and the modified .37's, the location you show in the picture was for echo monitoring and a stereo pan pot which allowed channels 1 & 2 to be narrowed to a more mono signal, through to being a reversed L & R signal. No regular pan pots on those channels of course.
 
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cardboard

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John, you write "...the location you show in the picture..."
But hold on: I'm referring to the rectangular 'Check' symbol way, way, way more to the top left. Here:

I like the metaphor of Hieroglyphs in need of translating. I'm in :)

and ps: I think the Check symbol has one single headphone shell in it.
 

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Winston OBoogie

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John, you write "...the location you show in the picture..."
But hold on: I'm referring to the rectangular 'Check' symbol way, way, way more to the top left. Here:


I was referring to the picture you posted that I'll attach again here.
In regard to that pic, I thought you asked: "I'm interested in the actual function of each of these 3 rotary controls."

I was merely saying that, the picture you posted is of a REDD.37 in "unmodified" state, which applies to the Studio One desk owned by Lenny K.

The Milan desk at British Grove is also in "unmodified" state.

All I meant was, in the manual for the REDD.37 and on drawings, it mentions that "stereo pan pots" were added to 2 REDD.37 desks as well as the 2 REDD.51 Abbey Road desks.
I don't have my documents at hand to check, but the details of what was there before the "stereo pan pot" will be shown.
My guess, without checking, is that, in the picture you posted, we see "spreader" type controls for channels 1 & 2, along with monitoring functions associated with echo.
Stereo pan pots were much more useful in Studio's 2 & 3 than spreader controls, hence the reason for the change.
Along with adding more positions to the mono pan-pots, going from 11 positions, to 21 positions.
 

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cardboard

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Yes, I know (In that very picture, way to the left, the Check symbol is visible). and then I start to ask about 3 rotary controls. I meant the three on the top end of the left wing of the .17...
Very confusing of me. Sorry!

So let's go back there :)

I think the left one(1) is a select rot. switch that selects 2 sources at once.
I think the middle one (2) is a volume control like the one for the mon circuit on the center section.
I have no idea what the right one (3) does.

Any better pictures out there?
 

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Winston OBoogie

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Haha, my fault too but, got it now.
OK I'll look around for pics. As I mentioned, the only REDD.17 documents I have are ones related to the .37 & .51 and none of them are details such as this.
I honestly don't know is my answer right now.
But now you've brought it up, I want to know.

I checked Peter's sketch for the REDD.17 (you have it) but nothing written there so... pics.

Maybe this should go in the REDD history thread?
 

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