tablebeast

OK, I have scoured the net looking for the genuine EMI Altec 436 / RS 124 mods and found a lot of info, but nothing concrete. In fact there seems to be a LOT of disinformation out there. I read a thread on here today that said this $100 "Recording the Beatles" book had the genuine info on the mod. Now I can't find anything confirming that this is true. I was hoping someone on here either had the info and was willing to share or was at least able to confirm that this book had the info. Can anyone help me out?
« Last Edit: May 25, 2010, 03:26:22 AM by tablebeast »


CroatianSensation

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #1 on: May 23, 2010, 01:30:57 AM »
I have that book...I'll pull it out and give it a look. Don't remember excactly.
A mind is like a parachute. It doesn't work if it's not open. -FZ

CroatianSensation

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #2 on: May 23, 2010, 01:42:32 AM »
Okay....here's the first bit mentioned:
"Initial modifications were basic and useful for EMI at the time:
-The Mains transformer was changed to handle the 240v/50hz mains.
-The input level pot, which essentially determined the threshold, was modified to a stepped rotary switch with
constant 200ohm impedance. This allowed perfect interface to EMI desks and tape machines, and the stepped levels
allowed reproducible settings.
-More importantly, as the original Altec 436B hand no output attenuation control, an Output Level control was added using
a similar 200ohm stepped switch.
-EMI added another creation of their own: a multi-position switch to vary the compressor release time, but using their own term,
"Recovery."
This 6 setting feature is very characteristic of EMI and the tradition continued through 1974...
The release times of the modified Altec range from .5 to 1.5 sec."

More to come....
A mind is like a parachute. It doesn't work if it's not open. -FZ

CroatianSensation

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #3 on: May 23, 2010, 01:58:16 AM »

Further mods:
valve substitutions which reduced noise and created a "harder" sound...numerous capacitor and resistor changes, new wiring and circuit layout; even changes of the valve sockets themselves. (no specifics are given in regards to these changes.)
A new front panel. "The only similarity to the original green Altec panel were the holes for the meter and the Input control. On the new gray panels EMI added holes for the additional Output and Recovery controls, and each was engraved with "RS124" and assigned a serial number."
Seems they changed so much on the way from the 436 to the R124 that, "the sole remaining trace of the unit's origin was the Altec logo on the meter itself."
Next they added a stereo linking function. "...an external lead that fed control signals between them so they would respond together....a switch on the rear of the case toggled the link function on or off."
Next was the "Balance" circuit.
okay. I'm beat. Hitting the hay. Hoped this helped. Not many specifics are given.
A mind is like a parachute. It doesn't work if it's not open. -FZ

tablebeast

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #4 on: May 23, 2010, 02:12:04 AM »
Hmm, so it seems like it was just a general description, but no schematic or specifics. Well, that's too bad. Anyone have a REAL modified schematic then? Someone has to, right?

CroatianSensation

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #5 on: May 23, 2010, 02:17:18 AM »
That'd be sweet but so far, in regards to the book, nothing super specific. I'll run through all the pages the 436 is mentioned tomorrow and post any other relevant stuff...if there is any that is.

A mind is like a parachute. It doesn't work if it's not open. -FZ

pucho812

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #6 on: May 23, 2010, 02:19:55 PM »
I'm sure winston has that info
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.

CroatianSensation

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #7 on: May 24, 2010, 11:24:12 AM »
I concur...
A mind is like a parachute. It doesn't work if it's not open. -FZ

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #8 on: May 24, 2010, 02:00:47 PM »
The question that I'm still awaiting an answer for is:

Why would EMI - a company that has been in the business of making records virtually longer than anyone else - choose to use, let alone modify that particular piece of PA gear?  With all it's attendant shortcomings as mentioned above, plus the fact that they built their own gear in house makes me wonder why it was even there in the first place.

Maybe some lo-fi aspect of its sound appealed to them?  If that's the case then it was that way as a factory non-modded unit.  The mods that CS posted seem to point more towards practicality than to alchemy - changing tube types to reduce noise, attenuator to match their 200ohm system, general level control, US/UK ac , etc..  .  So I'm seeing converting PA spec to broadcast/recording spec and still wondering - why didn't they just build/use their own?  In a sense it sounds like they sort of did.  Maybe other practical reasons - short on in house limiters at the time?  The Beatles fascination with American records?

EmRR

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #9 on: May 24, 2010, 02:20:22 PM »
I would swear I've seen a mention in an older book suggesting that it was a matter of producer pressure to get something in, versus the slow development cycle of in-house engineering.   Accounts seem to suggest getting new equipment was sort of like waiting on NASA to okay a new CPU for the space shuttle.   Maybe accounting caved to the pressure and placed an order for an off the shelf product, rather than continuing to listen to the *****ing.  I seriously doubt it had anything to do with how it sounded.
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde


CroatianSensation

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #10 on: May 24, 2010, 03:16:58 PM »
According to the Recording book I have that Tablebeast was asking about...and this is off the top of my head as I am not at home at the moment...they were seemingly emulating the Fairchild in many aspects and it was a slow process. Not all the mods were done at once and from what I recall the first batch was done around 1963. Don't quote me. I'll check it again. Seems like a lot of work to make the Altec useable and or sound like other pieces. Maybe it was accounting that forced them into action.  Either way it's interesting.
A mind is like a parachute. It doesn't work if it's not open. -FZ

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #11 on: May 24, 2010, 04:10:17 PM »
I would swear I've seen a mention in an older book suggesting that it was a matter of producer pressure to get something in, versus the slow development cycle of in-house engineering.   Accounts seem to suggest getting new equipment was sort of like waiting on NASA to okay a new CPU for the space shuttle.   Maybe accounting caved to the pressure and placed an order for an off the shelf product, rather than continuing to listen to the *****ing.  I seriously doubt it had anything to do with how it sounded.


I do recall reading about the band's struggle to get an 8-track machine and EMI not going for it.  A certain stiffness when it came to 'proper procedure' - maybe some of the upper staff frowned on (too much)compression?  I vaguely remember an article discussing that in regards to using the Fairchild on drums. It was kind of in line with the red tape situation you mentioned - being somewhat of a big deal when it came to requesting any type of changes.

According to the Recording book I have that Tablebeast was asking about...and this is off the top of my head as I am not at home at the moment...they were seemingly emulating the Fairchild in many aspects and it was a slow process. Not all the mods were done at once and from what I recall the first batch was done around 1963. Don't quote me. I'll check it again. Seems like a lot of work to make the Altec useable and or sound like other pieces. Maybe it was accounting that forced them into action.  Either way it's interesting.

It's interesting in general to see the number of non in-house pieces that were there - Pultecs, Fairchilds . . .  The Fairchild seems to make more sense in terms of actively trying to emulate sound and performance. The Altec would have been cheaper on the fly. 

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #12 on: May 24, 2010, 05:54:50 PM »
http://mixonline.com/recording/interviews/audio_geoff_emerick/

"Really, it all started when I was mastering. We used to get American records in and wonder how they got the sounds they did. We, of course, were limited to EMI equipment. There was no outside equipment allowed in, apart from a few Altec compressors. If they did bring a piece of equipment in, they took it apart and rebuilt it…just to find out how it worked, I guess."

I seem to remember a story where Sir George was saying that they had researched American recording methods in trying to achieve the same loudness and bass qualities and found the Altec in a lot of the studios that the records they liked were recorded in.  So they bought some (they were cheap enough) and brought them over.  Once the techs got a hold of them to convert them to 220v, they figured why stop there?  


sodderboy

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #13 on: May 24, 2010, 08:54:42 PM »
Tablebeast!  A round for everyone to celebrate the 'beast's return from the eastern front campaigns!
Mike

tablebeast

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #14 on: May 24, 2010, 11:07:42 PM »
Tablebeast!  A round for everyone to celebrate the 'beast's return from the eastern front campaigns!
Mike

Thank you, I had a long time spent at the bottom of a well and then some health problems to top it off. I'm doing much better now and tackling a LOT of new projects. I have some cool mods done to Tube based tape machine amps coming up that I will have DIY blogs with some seriously detailed step by step tutorials. Starting with the Akai/Roberts modules, then some Magnecords and some Ampex units as well.

I want to do the mods to the Altec because a friend bought one and has buyers remorse in stock trim. I told him the real mojo those are associated with is from the EMI modded ones, not the stock dogs. SO, I want to mod up this one and build my own clone into an Akai module as well. When I get the confirmed and proper EMI mods and then couple them with all the other useful mods out there I will also put THAT up on a full fledged DIY tutorial with pics, videos, recorded samples, etc.

So, anything anyone can do to help here will be a big step towards helping anyone and everyone interested in this topic. Send me the info via PM and I will keep your identity secret. I'm not afraid of EMI shutting me down, they can eat it as far as I'm concerned. I'll put a server on Sealand if that is what it takes to get this kind of info out there. Up next, anyone got the RIGHT schematic for the REDD47? All I can find is questionable info there as well.

bkbirge


tablebeast

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #16 on: May 25, 2010, 03:29:29 AM »
Drip 47 scheme here: http://dripelectronics.com/community/showthread.php?tid=425

Have to register to see his schem and he is not allowing new registrations.

bkbirge

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #17 on: May 25, 2010, 01:09:35 PM »
Yes he's registering new people. Just send him an email, he's disabled registering on the web because of spam. Anyone is welcome.

Here's his email...
[email protected]

Drip 47 scheme here: http://dripelectronics.com/community/showthread.php?tid=425

Have to register to see his schem and he is not allowing new registrations.

leigh

Re: Recording the Bealtes Book, EMI RS124 / Altec 436 Mods?
« Reply #18 on: August 13, 2010, 01:48:30 PM »
I want to do the mods to the Altec because a friend bought one and has buyers remorse in stock trim. I told him the real mojo those are associated with is from the EMI modded ones, not the stock dogs. SO, I want to mod up this one and build my own clone into an Akai module as well. When I get the confirmed and proper EMI mods and then couple them with all the other useful mods out there I will also put THAT up on a full fledged DIY tutorial with pics, videos, recorded samples, etc.

I am 100% behind this effort. I've got a 436c that I've been trying to improve on for years - check my postings here for a partial history of that.

Certain parts of the EMI circuit mod (the RS124) can be deduced from what is publicly known about the faceplate - for example, replacing the release knob with a 12-position stepped switch for 6 different recovery times, with a "hold" setting (i.e. infinite release time) in every other switch position.

Other parts of the RS124 circuit have been publicly discussed but not confirmed. Plate balancing, cathode balancing, upping the coupling capacitor values.

The only people who know for sure are techs who have gotten to see the originals (Abbey Road engineers, and those who came sniffing around later). And those vary, unit-to-unit, as is explained by the folks at Abbey Road plug-ins, who included switching between emulations of 3 different serial numbers in their plug-in. The design evolved over the years, back in the 60's, and so guess what? There is no single "real" RS124 circuit!

John Hinson claimed to know the real RS124 circuit. In fact, in his only post ever on Gearslutz, he claimed that only 3 people have the real schematic. And in addition, one of those people, an unnamed "older gent from abbey rd. studios", got the schematic from Hinson himself. The 3rd person? Unnamed also, but "The other person with the correct schematics will also not send you a copy." That was in October of 2009 - now that Abbey Road plug-ins have researched the RS124 for their plug-in, there are presumably more than 3 people out there with circuit diagrams from the originals.

Now, given that Hinson has turned out to be a less than trustworthy source, it definitely calls the veracity of his claims into question. He build and sold these RS124 units as the real deal, fetching prices for them that he couldn't have gotten if they didn't have that magical EMI/Beatles aura around them. I'm not saying he didn't build good compressors, but who's to say how authentic his circuit is?

Anyways, I'll wrap this up by saying that the shroud of secrecy around the RS124 circuit rankles my intellectual curiosity. I want to know how they put it together, just for the sake of understanding the thing, and those who refuse to share knowledge that they themselves did not derive really bug me. In other words, if you're an original Abbey Road engineer who designed and built the RS124, and you don't want to share, then fine. But if you're someone who came along and copied their design, yet won't share, then you stink.

Leigh

pucho812

Re: Recording the Beatles Book, EMI RS124 / Altec 436 Mods?
« Reply #19 on: August 13, 2010, 02:39:52 PM »
fwiw I demoed the rs124 plug in... If the real units behave like that, then I see no need to ever use them... in my personal taste they didn't really work in a manor I like and were very one trick pony. however they did sound good. I just did not like how the units worked in terms of attack times, release times, etc,etc.
You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is.


 

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