Fousrite ISA 110 channel strip

I came across a video about the history of Focusrite. In the early days when Rupert was in charge he  designed the ISA 110 channel strip apparently based on designs he did for his old mate George Martin at AIR. Great things were apparently said about it but I cannot seem to find any info on it. I did find a pic of George Martin holding one but that is it.

Cheers

Ian

Nice channel amps.  Lundahl 1:5 (LL1538?) on the input, toroid output transformer.  All the main amplifier blocks are 5534's.
The EQ points are well chosen and will get you where you need to go unless you need full parametric precision.

Although the desk has been further modified since it was first built,  I've had the pleasure of taking the Focusrite desk at Ocean Way for a drive and  I do think it's a nicer desk than, say, a Neve VR.  Not many Focusrite desks were built which is a shame really.

No idea what the new Focusrite stuff is like but the circa 1980's stuff was top notch.

Two originals built, well almost built and the techs came to Cambs to scavenge all the bits they could.  Electric Lady and Olympic in London I think?  All the potted amps popped in the first 100 hours and they had to pipe AC right into the desks to avoid meltdown.  Hutch has a million stories, and what didn’t kill him made him way strong.
IIRC the original rack modules have sip relays that are no longer made.  They are a bear to recap as well.
Mike

I thought 110s had parametric mid with selectable hi/lo shelf.  I only worked with one once but had a great snare sound out of it.  I had more experience with later Reds and Blues.  The coupling caps make all the difference in the sound.  The old caps  get very tired.  New ones bring them back to life.  They are impressive to me as mic Preamps after a recap with that Lundahl mic transformer . Lots of 100uf caps at least 60 in a Red 6.  Much easier to work on than the 110 from the sounds of things.

I thought the relays were still available from Pickering in the U.K., series 107. But yeah, no fun to recap.

I think the consoles weren’t quite finished when they were sent out. I remember the one at Electric Lady needed a ton of work before it was useable. I think mostly automation.

I’m more familiar with the ISA115 than the 110 but they sound excellent. I forget what pots and switches they used but they were expensive feeling.

fazer said:

I thought 110s had parametric mid with selectable hi/lo shelf. 

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Yep, they do.  There's no 'Q' control but, for almost every need, it'll do what you want without needing to patch in an outboard.

Gold said:

I forget what pots and switches they used but they were expensive feeling.

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I don't know the pots but the original ISA-110 used Elma 01 series switches.  I've seen Grayhill switches used in a newer 110 reissue thingie.

Edit:  One thing I remember regarding the desks is that there was local summing per each 8 channel bucket which kept each mix amp working within a reasonable gain range.  From what I've since read in Doug Self's book, there's also a noise advantage with this type of "hierarchical" mixing.   

I was told by the old ocean way techs that their desk was mixed up.  Someone at focusrite ordered the wrong genders on connectors so the backplane that the channels connect into has male pins and the channels have female pins.  there is also no guide rails for the modules, so they only real way to know if you got the channel in correctly is to turn the board on and see if you let the smoke out.
Their board also has a lot of mods that they did. I don't know what exactly was done but apparently it was extensive,  but without specifics that could be anything from cosmetic to jumpers to who knows. 

pucho812 said:

I was told by the old ocean way techs that their desk was mixed up.

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was that the console Jack Joseph Puig was using for many years?

Whoops said:

was that the console Jack Joseph Puig was using for many years?

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That's the one.  He was pretty much in permanent residence there.  Amazing room to walk into if you weren't prepared.

Thanks for all the anecdotes. Anyone got any pics, schematics, manuals??

Cheers

ian

I have no first hand information... but I do know a little about early production issues with large format consoles. Manufactures do not routinely discard or junk prototype/pilot production runs. There is a huge incentive to convert those early builds into cash.

Unfortunately as I like to joke, consoles are the hardest simple products to design. Hidden flaws often only reveal themselves after tens of modules are racked up together and put into use.  Sometimes only after being installed in a customer's studio (don't ask how I know that)  :.

JR

Whoops said:

was that the console Jack Joseph Puig was using for many years?

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yes it was.  Then he was talked into moving rooms into another space which had a Neve 88R

ruffrecords said:

I came across a video about the history of Focusrite. In the early days when Rupert was in charge he  designed the ISA 110 channel

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Is this the video Ian?

https://www.youtube.com/watch?v=bJd8606oNNk

Yeah I devoured that vid few years ago; frame of my beast was shamelessly inspired by it, as well as aux and summing blocks.  Sorry Ian, I don't have any schematics.  I recall someone a while back... perhaps Volker? sharing some pictures of the orange pumpkin output tx's.

Couple of you have had the chance to mix on a Focusrite? Jeeze..Lucky folks!

Whoops said:

Is this the video Ian?

https://www.youtube.com/watch?v=bJd8606oNNk

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That is the one. yes.

Cheers

Ian

The  Technical Documents section has now both the console and the stand-alone version: https://groupdiy.com/index.php?topic=44818

/Jakob E.

Thanks for posting Jakob.
My memory was wrong re. the mid bands, I see it does indeed have 'bandwidth' controls.

gyraf said:

The  Technical Documents section has now both the console and the stand-alone version: https://groupdiy.com/index.php?topic=44818

/Jakob E.

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Many thanks for that. Rupert using a Lundhal input transformer - who'd a thunk it?

Cheers

Ian

Looking at the 110 stand alone version schematic in the Tech section,  I see more info on the pots.  Dual 10k linear for bandwidth seems unusual.  I normally see 50k to 100k and also reverse logs if my memory is working .  Also it has a bandwidth control.  Better labels on parts in this sch.   


JP’s room is a thing of beauty.  But it would be a full time job for 3 techs.    Some great albums have come out there.