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Exclusively for LUNA Recording System

(21 reviews)

Get the punchy sound of API console summing — exclusively for LUNA.

The sound behind five decades of landmark albums, API consoles are legend for good reason. From Stevie Wonder's Talking Book and Fleetwood Mac's Rumours, to The Cure's Pornography and Radiohead's Hail to the Thief — the mid‑forward punch of API's classic analog consoles breathe aggressive, multi‑dimensional color into your mixes.

Developed in partnership with API, exclusively for LUNA Recording System, the API Summing Extension emulates the 2520 op‑amp and custom output transformer-based summing amps found in legendary API consoles over the past 50 years — giving your LUNA mixes all the attitude and tone of API's esteemed analog desks.

Easily add power, clarity, and mid-forward punch to your mixes with the first authentic emulation of API analog summing

Use per-bus Headroom and Trim controls for subtle tone sculpting over your entire mix.

Harness the complex nonlinearities and musical clipping that define the API sound

Sum individual channels or your entire mix through API's hallowed bus or master summing modules

Genuine API Summing for your Mixes

Genuine API Summing for your Mixes

Taking you beyond any summing plug‑in, the API Summing Extension is built into LUNA's mixer, capturing the sonic detail of API's iconic bus channels. This workflow eliminates the need to manage multiple plug‑in windows. Simply push up faders and use the per‑bus Headroom control to add character and dynamic enhancement.

Why API Summing?

Why API Summing?

When audio sources flow through an API console — specifically the 2520 op‑amp and custom output transformer — random analog nonlinearities work together, producing complex, musical harmonics and transient clipping. These summed signals add punch, depth, and character for a mid‑forward, lively mix.

Getting it Right

Getting it Right

UA dissected and studied multiple API consoles — pouring over original service manuals and gaining crucial insight into their discrete Class A operation and hybrid voltage/current summing circuitry — in contrast to the Neve 80 series pure current summing. UA's team of engineers throughly emulated all of the nonlinearities and clipping characteristics, plus API console fader taper and pan law, giving you the same chart‑topping results as API's flagship consoles.


The first authentic emulation of API analog summing

Adds power, clarity, and mid-forward punch to your mixes

Per-bus Headroom and Trim controls for professional tone sculpting over your entire mix

Sum individual channels or your entire mix through API's hallowed bus or master summing modules

Customer Reviews

API Summing

Overall Rating

(21 reviews)

R. Vargas

January 24, 2023

Brining everything forward with punch

I was skeptical about this one as it wasn’t as dramatic effect as the Neve summing but flipping back and forth, I can hear that API punch and clarity everyone talks about. Can’t vouch for how authentic it is compared to the hardware but if people with API console experience dig it, it works for me.

J. Whitesides

January 24, 2023

Complete the Sum

This is a fantastic addition to completing what I'd call the API trifecta. Having the API channel strips, pre-amps, EQs, Compressors without the API Summing in LUNA is doing yourself a disservice. I've become a Summing convert, for both the API and the Neve. Whatever the mojo is, it's a much needed additional tool in the mixing war-chest for that added extra 1% to put you over the top.

E. Morgan

January 16, 2023

Just brilliant.

This is a brilliant pluging on the stereo main. Glues everything together and adds weight and punch.
I currently have this on the main of a session that's got a Zeppelin vibe, especially the drums, and A/B'ing it in/out at unity gain you can 100% hear the difference it makes to the overall mix.
Glad I grabbed this one!

E. Morgan

January 16, 2023

Just brilliant.

This is a brilliant pluging on the stereo main. Glues everything together and adds weight and punch.
I currently have this on the main of a session that's got a Zeppelin vibe, especially the drums, and A/B'ing it in/out at unity gain you can 100% hear the difference it makes to the overall mix.
Glad I grabbed this one!

S. Lopez

January 8, 2023

If you switched to Luna

Then Grab It along with the Neve, simple.

K. Houghton

January 7, 2023

I’m a summing convert!

I never used this approach in a daw but now hear a great difference on many songs and now I will have to redo many songs I thought we’re finished
Give it a shot and you’ll understand .
Happy mixing!

A. Filip

January 3, 2023

Smooth Sound

Very good on percussive material and it’s really useful for gain-staging your tracks! You can hear something’s changing only when you just put in on your bus

J. Tofte

December 16, 2022

Glues it all together

It’s like loctite for audio. Great job UA!

T. Laja

September 19, 2022

API Quality

I used in fx and mix channels. Very good and easy .

J. Lowman

July 27, 2022

only for people new to DAW.

i'm not about to switch daws for a summing plugin. although i'm not even sure if it would even integrate as easily as it does with luna. COLLAB WITH APPLE FOR A LOGIC PRO X summing SLOT PLEASEEEEEEEE!!!

M. Verblakt

July 8, 2022


I loved the Neve summing option in LUNA. That's the reason why I obtained the API summing too. This creates the all American console sound. Love it!

W. Krol

June 5, 2022

API sound

Open wide sounding API summing - and working natively, Great job


May 27, 2022

Why ?

Why it's not avalaible for all DAWs users, not only LUNA ? Such a shame guys.

A. Lopes dos Santos

February 2, 2022

Game Changing System

The combination of the Summing and Tape Extensions inside Luna represent a game changing solution, I believe. The effect this system has on the final result of my mixes is simply amazing.
If I had the chance to have jsut one of the now available summing options, I’d take the API, which is less “colored” than the Neve - that might work wonders on some recordings, of course. The API has the typical “bite” we all associate with their products, but also provides lots of clarity and, to my taste, has a gorgoeus effect on the low end frequencies of the mix.
I’ve never heard/felt that “velvety” low end on my mixes, before using this combo (API Summing and ATR-102 Tape), inside Luna.
I work exclusively ITB and this setup has just made me yet more confident that, today, it’s absolutely possible to remain ITB, from start to finish of my work, with no regrets. Congrats, folks!

E. Souza

December 9, 2021

Totally Wow

Excellent, I love it


September 19, 2021



U. Khan

January 12, 2021

Excellent aggressive, mid-forward sound great on drums and guitar

This is a welcome addition to LUNA summing. This is a very nice, aggressive sounding emulation of the 2520 op-amp. This really shines on guitars and drums. Don't be afraid to drive it. Sounds great in a mix.

P. Jonsson

January 4, 2021



A. Thomas

December 20, 2020

Subtle big-board magic on native processor power.

I agree with the other reviews. In short, it makes any in the box mix feel better and more cohesive.

Technically, I love the balance of simplicity and control they’ve implemented with this system and the tape extensions.

I had purchased Studio One 3 a few years ago for its summing emulation. The control and implementation of the UA summing feels easier and faster to work with, though I’m guessing you could get similar results with both.

Sonically, depending on how developed your ear is, you might not “hear” much of a difference on one track, but put this on all your busses including master bus, play with “headroom” a bit on each track to taste, then toggle the whole thing off and on like they do in the videos. Listen as much with your feelings (“Reach out with your feelings, Luke”) as your ears; you’ll notice the difference. It’s a subtlety that makes one of the differences between a good mix and a great mix.
Between this and the Neve summing, for my tastes I would take the API if I could only have one, but fortunately you don’t have to spend $100,000 to buy a console anymore to have that luxury.

I have found that for some songs I’ll mix and match a Neve summing buss for certain elements and API for others because of the difference in vibe. Well done and well implemented, UA!

One note of joy and caution: extensions (shape, ravel, summing, tape extensions) run on your computer’s CPU. This means that you don’t lose an ounce of UAD DSP to run this! BUT you will use an amount of your native processing power. I’ve found that as of Luna 1.13, I can only run my render/native CPU at around 40-50% and have things stay stable. That’s on a 2012 MBP i7 with SSD. That however is enough to run all the extensions I need for most mixes on my system. On occasion I need to give up an extension on a less integral bus such as low volume harmonies or percussion parts, but generally it’s fine.

S. Shaw

December 10, 2020

Clear and vivid!

I'm surprised there hasn't been a review yet. Think it somewhat like the API Vision channel strip. It's not as colored as the Neve summing, but gives extra bit of clarity and definition that really helps shape a mix (or even make a demo!) Love it on acoustic materials.

A great bundle sale in the Analog Essentials bundle. Thanks UA!