News:

GroupDIY is currently under construction.
Some parts of the site may not work properly.



Sammas

What was the API 325 line amp actually used for??
« on: August 27, 2005, 12:33:12 AM »
Line input drivers?
post fader gain stages? (might explain the Aux connection)
Summing amps?
All of the above?


What was the API 325 line amp actually used for??
« Reply #1 on: August 27, 2005, 10:07:41 AM »
d) all of the above

 :green:
Seth

The definition of insanity: "Hey, this thing could be really cool - if I had the money to fix it up, which I don't, but if I did it could be really cool - if I had the time, which I don't, but

Sammas

What was the API 325 line amp actually used for??
« Reply #2 on: August 27, 2005, 09:26:26 PM »
Quote from: "jrmintz"
d) all of the above

 :green:



 :thumb:

thats a lot of 2503's and 2520's


thanks  :guinness:

rickc

re: What was the API 325 line amp actually used for??
« Reply #3 on: August 30, 2005, 05:16:31 PM »
In the 70's, I worked at a studio that had 2 API consoles. We had 515E input modules; they were 16-bus boards and inputs 17-24 went direct to the tape machine. There were transformers everywhere! Essentially any stage that drove a patch point had a transformer in the path: mic pre output, eq output, module direct out, mix ACA out, line out.

This console had 325's in it, but it also had many purpose built boards in it. These boards were used for summing amps (4 to a board IIRC). There were 325s used for miscellaneous gain blocks, the talkback preamp, and line outs.

I'm working from memory here, and somewhere I have a blueline drawing showing what's what/where.

What was the API 325 line amp actually used for??
« Reply #4 on: August 30, 2005, 06:15:14 PM »
Hi Rick,

That would be fascinating to see-

 :thumb:  :thumb:
Seth

The definition of insanity: "Hey, this thing could be really cool - if I had the money to fix it up, which I don't, but if I did it could be really cool - if I had the time, which I don't, but

SSLtech

What was the API 325 line amp actually used for??
« Reply #5 on: August 30, 2005, 11:24:23 PM »
The last two Deep Purple albums that I worked on were done on a custom console which was basically two 16-buss APIs welded together. It's still here in town and I have to do a few things at the studio as soon as I get back from California... I can probably take a few pics but yes... the console has transformers everywhere!!!

Keith
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

PRR

What was the API 325 line amp actually used for??
« Reply #6 on: August 31, 2005, 02:04:49 AM »
> What was the API 325 line amp actually used for??

Line amps drive lines. They make almost a watt or more, may or may not have tons of gain, may nor have lowest-noise inputs. They pump signal out of the box, out of the studio, maybe across the state.

The partner is an input amp. LOWest noise, good but not excessive gain, maybe not quite 1/10th watt output. Just brings weak signals into the box, where you fiddle it and pass it to a Line Amp to a destination. Also used to boost signals that have been fiddled too much (lossy mixing networks, passive EQs, etc.)

In the 1920s, you would have intermediate amps as well.

By the 1940s, they consolidated on Input Amps with low noise and modest output, and Line Amps with ample output to drive several lines and pads at high level.

Around 1960 you find the two functions merging: one amp module with low noise, ample gain, and ample output power.

Early transistor amps could just about get low noise OR good output, but didn't get both in the same module. Later amps did, and the difference between an Input and a Line amp might just be whether the mike transformer was included.

I suspect the beast you refer to can be either/or, depending on transformers. Older transistor amps need input trasformers for lowest noise from 200 ohm mikes. They don't need output transformers to make power in 600 ohm loads (as tubes do) but any line not dedicated to another input may want a transformer to break ground and balance the signal. In small systems you might have 6 input irons and one output iron; mega-systems might have iron everywhere.

soundguy

What was the API 325 line amp actually used for??
« Reply #7 on: September 03, 2005, 09:39:33 PM »
probably better to dissect it even further than that.  You got an opamp, and output transformer and basically the stuff to make the input work in the circuit.  The main difference between the 312 mic pre and the 325 is the input transformer and the stuff in the circuit to make the input work.  Anyhow, api used that same opamp and output transformer everywhere on the console, including the EQ, so its not like those building blocks are only present in just the line drivers or just the mic pre's, its every single stage more or less.  I guess there was a 2510 variant but for the most part, the entire console was built out of those blocks if you look at the old consoles before the VCAs came into play.  On my console, its blocked out the same way, one opamp does everything.

dave

chips are good with dip...

Flatpicker

What was the API 325 line amp actually used for??
« Reply #8 on: September 03, 2005, 10:56:26 PM »
Quote from: "SSLtech"
The last two Deep Purple albums that I worked on...
:shock: WOW! I'd like to hear about that if you ever get time to post about it in the Brewery.

cuelist

What was the API 325 line amp actually used for??
« Reply #9 on: September 04, 2005, 03:01:37 PM »
Quote from: "SSLtech"
The last two Deep Purple albums that I worked on...
Keith


Which ones were they? I listening after "perfect strangers" (1985?) but perhaps there were some good stuff after that as well.
Mr K


Sammas

What was the API 325 line amp actually used for??
« Reply #10 on: September 04, 2005, 09:09:14 PM »
Cool thanks guys!  :thumb:

adrianh

What was the API 325 line amp actually used for??
« Reply #11 on: September 06, 2005, 04:35:57 PM »
I bet that console had two things;

It sounded good even with all those transformers.

It did not have any hum from ground loops.


 

Related Topics

Subject / Started by Last post
Last post August 19, 2004, 02:21:53 AM
by b3groover
Last post September 18, 2005, 04:22:19 PM
by NewYorkDave
Last post November 29, 2005, 01:22:19 PM
by Mlewis
Last post January 03, 2007, 03:32:27 PM
by Rob Flinn
Last post July 09, 2014, 05:35:45 AM
by ruffrecords