The API 2500 stereo compressor is my compressor of choice when it comes to my 2-buss mix. I mix mostly 'rock' genres, and this compressor glues my mixes together very nicely. I usually mix into this compressor with the gain reduction kissing around -2db. It's subtle but makes a big difference for me.
This device is laid out in a very straight-forward design which makes it easy to use and understand all the controls. It has the typical threshold, ratio, attack & release controls of many compressors, but it also offers some interesting others. It comes with API's patented "Thrust" circuit which I tend to leave on medium or normal, unless I'm looking to really crush something and get that pumping vibe happening (loud). It also has a knee control and API's "new" or "old" switch, which basically changes the compression from feeding-back or forward-feeding compression. Both offering unique results. The other controls include stereo linking, which lets the 2 channels (left & right) compress individually or work 'linked' together in increments of 60, 70, 80, 90, or 100%. Also has a hi-pass and low-pass option. Finally, the output section includes a bypass AND "in/out" button, in case you'd like to keep the "sound/color" that the unit adds to the signal, without actually using any compression. It definitely has a "color", which API is known for. In particular, I love the saturation/glue I can get from the "make-up gain" knob. There are lighted VU meters for each channel with a switch for viewing In, Out & Gain Reduction.
This comp is known to shine on the drum-buss. I like to use it for tracking vocals as well. Highly recommended and I can't foresee myself ever selling mine.
This is a very sweet sounding mix buss comp limiter.
I have really enjoyed using it though these days I mix into a console without 2 buss comp, but for those wanting to mix into a 2 buss comp this is one of the best.
You can dial in vintage 70's feel with the old feedback switch really slow and thick.
The feed forward more of a Paul Wolf take on the C2.
I like the thrust circuit which allows a sort of pre eq/sidechain to the detection
circuit on the loud setting one can get a very transparent comp even at heavy settings.
I love the sound of this piece, and while some say its versatile I would say it has a very identifiable signature , not in a bad way.
This is no distressor or germanium comp though so I would hesitate to praise it for versatility.
You can get away with very heavy compression and remain musical but I prefer to accomplish this on stems sub groups individual tracks, too much buss comp is not my thing.
However using this thing with very gentle settings can provide nice subtle enhancement.
Learning a comp is harder then buying one, so read all about it here on GS to learn how others approach it.
I like the unlink feature nice to hear the effect that sometimes helped a mix.
I did sell mine but really do enjoy the sound , just not as crazy about comping everything with a blanket, I wish this thing had a parellel comp / mix knob can't live without it!
I do think however for this task this is a great comp.
Since I bought the API 2500 I used it in every session and I wished to have at least 4 of them
It sounds always "thick" and good, always musical (will hardly screw your sound). When compressing just a little the API sound isn't that obvious, but when pushing the 2500 more you'll get more of its sound.
I love to use it on stereo sources: especially drum buss, choirs and rhythmic synths. I'd say it gives them a nice smack. Wasn't convinced on the mix buss (I believe in letting the ME do the master job and I don't want to screw with the mix buss) and with strings and pads. For a mono bass I think it's a waste to use 2 channels.
It's an easy gear to use, still I'd give a 7 for the ease of use. Mainly because the vast possibilities with its features is dependent on the user's experience. The Thrust-, New- & Old-Style compression and the stereo link features aren't easy to hear or to use correctly. Although I find it hard to screw up any sound with the API 2500.
Cool feature is to bypass the compressor section, but still running thru the trafos. Get the famous API sound without compressing! heh
You'll find the usual parameters on it (threshold, attack, release, knee) , plus the famous API auto make up gain. I love the last feature, because you can experiment with different and even extrem settings and bypass it, without having to correct the gain all the time. The VUs can be switched between in, out and GR.
The API 2500 is built like a tank. Very good quality. The knobs and buttons feel good and the labels are clearly readable. Plus it takes just 1 RU heh
The manual is a joy to read and gives very good explanations, for starters and even experienced users.
Summary: It's not cheap, but you get a very good compression bang for your buck. It can complement any existing array of compressors, or it can be you first to go outboard compressor.