DCC Archive Ampex Multitrack EQ Question

Luke,

Regarding the stereo mixes on Who's Missing:

As I remember, the stereo mixes were actually kind of midrangy, and I did this type of EQ to them:

-2 @ 3000 cycles, +2 @ 10,0000 cycles, +2 @ 50 cycles.

Of course, these were mixed by someone other than Talmy at IBC, since he doesn't recall that these exist.

But, Talmy would never have used AME. No British producer or engineer would have. Talmy would have added console EQ instead.

AME, or "Ampex Master Eq" curve was invented by some genius at Ampex to help reduce tape hiss. When you used it, it added (among other weird ****) +8db at 1000 to the recording. When you played it back, it SUBTRACTED 8db at 1000.

Problem was, IF YOUR RECORDING LEVELS WENT INTO THE RED AT ALL, YOU HIT A WALL OF MIDRANGE DISTORTION THAT COULD KILL YOU, cause the thing just overloaded, and not in a nice way. Just listen to any RCA Living Stereo LP master AME tape recorded after 1959! Ouch!

So, engineers who liked to use tape saturation for compression would never use AME.

Talmy (and most British folks back then) liked to push the meters at levels of +12 to saturate the tape!!!! Even today, the "0" set up tone on an analog tape machine is only +3. That is 3 db above the old "0 vu" setting established back in 1954.

So, as you can imagine, recording at +12 is darn hot, well into extreme saturation. This is the reason that Talmy says that there is no tape hiss on the three tracks. The music was recorded so loud on the tape, that the hiss (way down there at -20 db) is not there.

If he tried that with AME, WHAM! They would have runs screaming.

I have an Ampex four track machine that has AME on it (if selected). It cost extra in the old days, but some engineers used it a little bit; ("Ring A Ding" LP by Sinatra was recorded AME).

I've never run across a British tape that ever did, though. Only CCIR (British EQ) or good old NAB (National Association of Broadcasters).

Most of the British rock tapes that I have worked with are +12 NAB (The Cars, Who's Next, Rod Stewart "Never A Dull Moment", Fresh Cream, etc.)

Oh, and the CORRECT AME EQ has not much to do with the top end, just the midrange.

This help?

 

John,

Welcome. The RIAA EQ curve has to do with phonograph records only.

Simply stated, the Recording Industry curve, which was standardized in 1954-55, means the following:

When a record is cut, the treble control is turned all the way up, and the bass control is turned all the way down, so the lacquer sounds pretty funky. But, it does two important things for the recording:

The bass is mostly removed, so the groove can be smaller. Bass information takes up so much space on a record, that without the bass cut, the side of an LP would be under five minutes, max.

The treble boost, helps to eliminate surface noise.

How?

Here's how: When the record is PLAYED BACK on your stereo, your Phono preamp has an RIAA decoder in it that adds the exact amount of bass back, and decreases the treble by the right amount, thereby taking the surface noise way down with it. You see?

Kind of a early Dolby type deal.

So, it's crucial that YOUR phono preamp has the correct RIAA curve in it. Most tube phono stages are off a little, and most moving coil carts vary from neutral as well.

That's it. The RIAA curve is still being used Worldwide when Phonograph records are cut, making the almost 50 year old stardard something of a survivor. A well cut LP when played back correctly can still sound amazing and lifelike; a true "analog" of a sound wave.

John, no question is stupid. Ask whatever you want!

 

I've heard of a "twelve track" that belonged to Mustang Records...Wasn't "Talk Talk" by the Music Machine recorded on it, along with the Bobby Fuller Four stuff?

Never actually seen one, or a 10-track for that matter.

Others have though, I'm sure..

 

Well,

In order to get 12 tracks on 1 inch tape, compromises have to be made in sound quality.

That is why recording engineers who cared about sound quality hated the 2" 24 track machines that replaced the amazing sounding 2" 16 track decks of the 1970's.

Adding 8 more tracks in without changing tape width ain't any way to run an airline, if you ask me.