Well Mike...I guess you got me there. Aren't you a clever one. I have spent many hours with ADR F 760-N's, and if Bob O. says the Helios was made by ADR, then I guess I have indeed played with the units, and rendered my opinion above.
As for having heard Zeppelin or the Stones, I'd have to say yes, but what does that have to do with anything. I was Jimmy Miller's engineer for a few years [if you read the credits on some of those late 60's early 70's Stones, or Blind Faith, or Traffic records you might be able to figure out who that was], I'm quite familiar with the production aspects of the RS records from that period.
I used to own the desk from Olympic, which was the desk on which Beggar's Banquet and Let It Bleed were made...rumor has it that Led Zeppelin II was mixed on it. It didn't have any compressors, nor was it a 'Helios' desk [though it did have many Helios parts in it, which I suspect were installed during later maintenance of the desk], it was an 'Olympic Sound Studios' desk, Helios was formed by Richard Sweatenham and friends subsequent to that particular desk.
I also spent a few years working for an artist who is known to have 'recaptured' many of those "old" sounds. I spent a significant amount of time hunting for a Helios desk for him to purchase [as well as a rather large variety of other 'old and cool' tools]. During that process, I probably ran into about 9 or 10 of the things, none of which had 'on board compression', yet almost all of them had different equalizers and routing. The two that were closest to being the same were the one I owned from Olympic, and the one in the Rolling Stones mobile unit, the main difference was the 'RSMU' desk had the most arcane "patch panel" known to man...which according to Jimmy Miller was a nightmare from the first day forward.
During that same period I met many if not most of the folks who made the recordings from that period. I learned quite a bit from them on a 'technique' level, as the hardware is really rather irrelevant if your technique sucks. The hardware is there to make things easier if you have technique, not to replace technique.
Glynn Johns [who claims to have been a principle of Helios, and with all his other accomplishments, I don't doubt it for a moment] is offering his desk for sale, it has 1176's and LA-2A's built right into the desk, but no 760's.
Now, that kinda makes me wonder at which point Helios began to install 760's, and why. If they are indeed the ADR units, then the size and shape would have been more than appropriate for installation in a Helios desk [from what I understand, the units were origianlly build for ADR desks, hence the shape and size], but when did they install them in Helios desks, and which desks had them?
It's really nice to see your love for the classic equipment. There was an awful 12-15 year period where the majority of the new equipment manufactured was almost all $*^t, and many of the classics were disposed of for the installation of "newer" and "better" [it was modern solid state, therefor more reliable, therefor considered "better"] equipment.
The fact of the matter is that unless you have all the manuals, and are performing regular maintenance, you have a little less of an idea of what that equipment really sounds like than I have of why you insist on being such a prick.
Do us all a favor, take a ^#$%ing valium [or 3], and give us a break. It's great that you seem to love your T'Funk and Helios stuff. Bully for you. There are certain bits of "old stuff" that I too find invaluable tools, but on occassion, keeping an open mind can often lead to a better product.
I personally don't really give a flying ^#$% what you do, when you do it, nor with whom you do it...but this 2 dimensional "my old $*^t is the only stuff that's any good" crap is wearing pretty thin. If you really start to learn the history of this stuff rather than the boring and blind repetition of "old is better", then I have a feeling you might get a better handle on what is really cool [and why it's cool], rather than parroting what some 'vintage gear' dealer told you.
As long as I'm wasting my time and making suggestions to you, may I suggest that you try a couple of things that have been made subsequent to the Reagan administration.
You seem to have a bias against Manley gear [and frankly, there are units like the Vari-Mu, where I'm in solid agreement with you], so perhaps you might want to avoid some of the units in that particular line [though the Massive Passive is probably the most interesting equalizer I've met in more than 20 years]...but there really have been some fabulous strides made in equipment design and manufacture since the mid-70's.
I frankly don't give a ^#$% what you think. It's packaged so poorly that it's really not even amusing anymore. What I do find funny, is that I've run into more than a few of your clients and co-workers over the years [I do a bit of work in Chicago, and you know how people love to talk]. Many seem to be of the opinion that you have way more attitude than aptitude, perhaps you may want to work that, perhaps not.
Either way, if you'd like to be welcome to hang out here, learn a new song, or at least learn to sing the old one in a manner that presents new information.
I don't care if that information is 'historical' or 'technical' or the discussion of a technique that employs your great old tools...but this endless drone about how great your old $*^t is, is frankly boring the snot out of me. I don't do this to be bored, I do this to have a bit of fun, and to learn things. If you really want to continue to make this adversarial, I suggest you do it privately.