Build your own REDD.51 desk

[Winston OBoogie]

Not a schematic, but still worth the bandwidth if you're anything like me:

 

[Winston OBoogie]

Money allocated for building a REDD.51 @ the Hayes factory was £8,000 in 1958:

 

[Winston OBoogie]

As opposed to £12,000  for building a REDD.37 in Germany:

 

[Winston OBoogie]

An early REDD.37 which was built in Germany but not destined for Abbey Road Studios.    Note the straight-line faders in lieu of Paintons and also no provision for changing the EQ from "Classic" to "Pop"

 

[Winston OBoogie]

The desk shown at the rear was also designated a REDD.51 but was used for transfers and mastering rather than studio recording.  The control surface housed equipment such as the "CurveBender" which was appropriate for that job rather than the usual control room stuff.

 

[warpie]

Nice! Thank you for posting this.

 

[Winston OBoogie]

Here's the "Top" EQ response as measured through the only known surviving REDD.51 desk.  It's inclusive of the whole desk path, from Mic in to Track/Bus out:

 

[Winston OBoogie]

Same thing for the Bass EQ response.  Both these show the "Pop" EQ of course.

 

[emrr]

excellent!

 

[Winston OBoogie]

Glad you enjoyed  Warpie and Doug

Here's a shot of some of the cabling and transformers inside the centre case section of the surviving  REDD.51

 

[pucho812]

nice stuff. I will add it to my redd  notes collection that I have been amassing.

 

[ruffrecords]

Lovely stuff Winston. Interesting to see the pop EQ high measured response differs from that published in Recording the Beatles.

Cheers

Ian

 

[Winston OBoogie]

Interesting to see the pop EQ high measured response differs from that published in Recording the Beatles.

I don't have a copy of the book any more to see what you noticed  but if it's substantially different then that is surprising. 
Even before the REDD.51 now at British Grove was located in Milan I'd given Kevin and Brian copies of the EMI documents showing all the EQ curves. 

 

[ruffrecords]

I don't have a copy of the book any more to see what you noticed  but if it's substantially different then that is surprising. 
Even before the REDD.51 now at British Grove was located in Milan I'd given Kevin and Brian copies of the EMI documents showing all the EQ curves.

Actually I think you are right. The Classical EQ hi band is shelving and the Pop one is peaking at about 4.7KHz (which I think is the same as the 4.7KHz band in the RS127 Brilliance box)

Cheers

Ian

 

[Winston OBoogie]

Actually I think you are right. The Classical EQ hi band is shelving and the Pop one is peaking at about 4.7KHz (which I think is the same as the $.7KHz band in the RS127 Brilliance box)

Ah OK, yes that's right. 
I don't believe there's any anecdotal or archived evidence that the REDD.51 in studio 2 at Abbey Road ever had the EQ cassettes switched from Pop to Classic, which makes sense since it was the main studio for pop and light music recording.  Studio 1 (with its REDD.37) being the main classical studio, along with Kingsway Hall of course.
I don't know whether that holds true for the 51 desk installed in studio 3 as I do know some smaller ensemble and piano classical recordings were made in there.

And of course, you're correct in that the RS.127 was indeed a bell shape EQ and has, for the most part, the same Q as the Pop EQ top end.

 

[ruffrecords]

Attached is the simulated response 4.7KHz response of my REDDEQ design.

Cheers

Ian

 

[Winston OBoogie]

Got ya.  In a multiple frequency EQ such as yours, it makes perfect sense to have the boost and cut be reciprocal. 
Since the desk EQ was a simpler fixed frequency top and bottom tone control,  it made sense for the top cut to be shelving.

 

[ruffrecords]

Got ya.  In a multiple frequency EQ such as yours, it makes perfect sense to have the boost and cut be reciprocal. 
Since the desk EQ was a simpler fixed frequency top and bottom tone control,  it made sense for the top cut to be shelving.

Exactly, my REDD EQ mimics the classical bass and treble shelving controls and adds a mid band based on the RS127. Hopefully best of both worlds.

Cheers

Ian

 

[Winston OBoogie]

Hopefully best of both worlds.

It becomes a more useful, all-round EQ that way for sure.

 

[matriachamplification]

Not a schematic, but still worth the bandwidth if you're anything like me:

This is a fantastic find. Thank you for the share.
Presently we are teaching our 12 year son (and I, really I am the one learning) to build out a EZ Tube Mixer with the topic of desk design a much heated conversation around the family dinner table.

We were torn about the EQ to select for our classic build. That said, maybe a micro-model in the fashion of the REDD shown may be in order.