Today I'm releasing SG-323, the first authentic emulation of the Ursa Major Stargate 323 Reverb. The Plug-In is based on more than five years of work and closely emulates the digital circuits of my own hardware unit. While staying faithfully close to the original it also improves on the hardware by enabling fully variable pre-delay and decay time settings.

The Ursa Major Stargate 323 Reverb was released in 1984 by Christopher Moore and builds on the success of the SST-282 Space Station. While originally being aimed at more budget-minded studios at the time, this reverb has become a rare piece of vintage hardware.

Features

• 8 reverb programs ranging from small Plates to thunderous Caves
• fully adjustable pre-delay & decay time
• Resizable UI
• DRM free & Open Source

SG-323 is available in AAX, VST3, AU & CLAP for Windows, macOS & Linux.

Try it: a demo version can be downloaded here https://store.greyboxaudio.com/download/SG-323_demo.zip
The demo has locked controls but you can switch through all the reverb programs.

Buy it: the full version is available as a one-time purchase for 34,00€ here https://store.greyboxaudio.com

Build it: the source code as well as build instructions are available on my github https://github.com/greyboxaudio/SG-323

I have not created any audio demos myself, but there's a nice playthrough here:


The video is using an older open source build of the plugin, but the sound & features have not changed. If you're interested in compiling the full plugin yourself, the source code is freely available on my GitHub https://github.com/greyboxaudio/SG-323

Alex Ball also did a video about the old Ursa Major devices:

Wau

This is my all-time favorite hardware reverb.

Thanks for releasing this!

What differences would there be between building the project one's self and buying the product from the storefront page?

haven't tried it yet but isn't the Auditory Space Station the first to try this? Be curious to hear comparisons

have you tried the plugin yet to see if it has the same feels?

I tried it, I liked it. It is more “reverb” than Space Station.

I haven’t yet no

That one to me is cool but not at all like a 323.

in what regard does it fall short?

Hey everyone,
thank you for your comments and your interest

The plugin itself will be identical but there will be restrictions to the available formats. Pro Tools requires AAX plugins to be digitally signed with proprietary tools from PACE as well as by Microsoft. Plug-Ins on macOS also need to be digitally signed by apple, so you can't install them in the system folder. If you put them in your user's ~/Library/Audio/Plug-Ins folder it should be fine.

The SST-282 Space Station is a different unit and was the predecessor to the Stargate 323. The SST-282 Space Station is a multitap delay that can also do some reverby things. The Stargate 323 is a full on reverb. Bonus trivia: the first SST-282 Plug-In was released by Princeton Digital / Eventide for Pro Tools TDM.

That is by design. While the Space Station was a multitap delay with some reverb features, the Stargate 323 was Ursa Major's first deidcated hardware reverb.

I'm really looking forward to your comparison My plugin is built on a complete digital emulation of the original circuit logic. Every single sample gets calculated the same way as it is done in the hardware. The filters have been modeled as well, including the anti-aliasing and pre/de-emphasis filters. My hardware unit is in great condition and I've replaced all electrolytic capacitors not too long ago.

Here's where I would expect differences:

• the Stargate 323 uses randomization based on the input signal level and different gain staging can make a difference
• the Stargate 323 has free-running modulation cycles that can span over multiple seconds. It is nearly impossible to catch the exact same internal timing twice and running the same signal through the hardware twice will also result in two different sounding results
• the plugin is equivalent to a perfect digital circuit. While I have not yet measured the clock stability of my own hardware, it's 40 years old now and I would assume there to be at least a bit of jitter and drift
• analog effects like distortion, component tolerances, component aging etc. are not modeled in the plugin

For me the Stargate 323 is about the vibe of the algorithm and not about component variances. If Christopher Moore wanted to sell products that need 30+ years to develop flavour he probably would have started a distillery

I'm no developer, but i am a cheapskate. I followed the instructions for building the vst, but no plugins appeared in the requisite folder.

sent you a PM

Here's where I would expect differences:

• the Stargate 323 uses randomization based on the input signal level and different gain staging can make a difference
• the Stargate 323 has free-running modulation cycles that can span over multiple seconds. It is nearly impossible to catch the exact same internal timing twice and running the same signal through the hardware twice will also result in two different sounding results
• the plugin is equivalent to a perfect digital circuit. While I have not yet measured the clock stability of my own hardware, it's 40 years old now and I would assume there to be at least a bit of jitter and drift
• analog effects like distortion, component tolerances, component aging etc. are not modeled in the plugin

I guess this explains a smooth and relatively dense tail.

With not too many controls I expect there is much more under the hood on every algorithm.

Could you share what you found out?

Now THIS is cool. Ugh I really wasnt going to buy another plugin any time soon but I love Ursa Major stuff. The Audiority plugin is one of the best delay/reverb units ITB and I use it on EVERY single mix. Very cool to see this, it sounds like a labor of love

I love the idea of this.

Love the vibrato-ey (less chorus-ey) sounding mod and how you can hear the delay lines tumble. Like “katchaw-katchaw” as it blooms and diffuses.
I’d consider it a “bad” reverb and I have a real soft spot for these.

I’m sad to admit I spent 2 days and failed at compiling it. Tried on OS 11.7 and OS 12.something but maybe it has to be OS 14. I manually installed the right versions of Xcode and cmake for my Macs. Now I’m struggling to remove the 32Gb Xcode install without destroying my OS, which is a whole thing apparently 😆. It’s a great price and I’m gonna buy it. Which means I’ll also have to buy Audiority’s 282 (it’d be rude not to). Just bummed I’m too inept for the home brew.

If you're eager to hear some sounds: Elektronick Musick did a really cool demo of the plugin
Make sure to subscribe if you like plugin demos that are all about the sound!

The Audiority plugin is amazing. I often use the comb settings on a vocal to add dimension without noticeable reverb or delay. Like Rugginz, I use it on almost every mix somewhere.

I'm very tempted by this 323 plugin. The demos sound great, right up my alley.

If you like grainy, lo-fi reverb and delay, I would also highly recommend the Audiority Vertiverb VRS23.

Space Station is $29 in my user account, maybe it’s time. It is my birth month after all. I didn’t like it on drums but I’ve heard it just doesn’t work well there (something about its rhythmic delay taps design). It did crazy cool things on elec bass and I’ll def try it on vocals.

I do own Verti-Verb and it’s never not on a send (or two). Mostly use reverb mode or short fast delays with slow modulation. Super colorful width on synths and vocals. Also Dark Memory is my go-to for slapback. It has this deep warm glow that somehow never gets muddy.

Can’t forget Korneff MicroVerb either!
CPU crusher but man is it cool.
I made an aux chan preset with El Juan, LevelLoc, MicroVerb, Pumpkin Spice, WoW Thing, and Puff Puff (in that order). If something sounds boring I just sentence it to death via that strip ������.

Ps. with El Juan I don’t even limit, I just mash all the input shaping buttons to see how LevelLoc responds.

It really sounds very shitty - in a cool way. Its more like a multi tap delay - definitely wont be using it on drums (maybe toms); and if I did I'd certainly put a "wetter" reverb after it.

The "delay" clusters are clearly audible in their transients, and seem to have a lot of top end energy that cuts through. So you can clearly hear the discrete delays, the plugin almost sounds like a tight burst of them, at least on transient material.

This stuff is hard to describe, but hopefully that gives a reasonably clear picture.

Its probably really cool on vocals - almost like a non-lin verb (one of my favs on vocals that's basically embedded in my template). I also have a bit of a secret I do with non-lin verbs....they have a lot of uses honestly - but on BGVS, one can create a very frenetic, urgent, and stressful sound by very heavily compressing and saturating some non-lin verb on a send with BGVs. Tucking that send a bit under the BGVS during the choruses, with a little stereo widening, can cause them to literally jump out of the speakers. It works very well with a regular chamber in parallel as well, which makes it more natural sounding. One of my favorite uses of non-line verbs.....I have a feeling that this could probably be used in that way.

Im sure I will find other uses for it as well - I have a feeling that it would REALLY like some modulation. I sort of wish there was a way to kind of tame some of the transient energy that the delays have, or fade them in/out a bit more - perhaps I can explore filtering the signal before it hits the verb.

A fun one!

Because its so limited and distinct, trying to find a way to incorporate it is itself is a creative exercise that I find very inspiring. In a world of limitless tools, stuff that makes you have to actually think creatively is very valuable to me

Haha, thank you for the review :D It definitely sounds shitty if you want a natural sounding digital reverb. But that's not what we're here for.

A nice trick with this reverb is to turn the decay time to zero. That way you only get to hear the output taps. If you turn the pre-delay down as well this can be used as stereo widening effect for mono signals. The 8 programs will all change the sound of the output echoes. And if you increase the pre-delay you can use it as a slap-back effect.

Also the HF/LF decay knobs are actually filters for the reverb input.

Awesome, thanks for the tasting notes!

Because none of the analogue I/O has been modelled, it sounds like the kind of thing I might use with Acustica Lemon, to get some box tone and kill the highs a bit.

Yep, I tried it. 23 taps give you a chorus, too.

Thanks for putting it out there, I missed it, was more interested in Space Station

Instant Harold Faltermeyer. Not that it's limited to that, of course, but that 80's sound has a very relevant vibe.

Been using the old one for a bit. Love this project. thank you.

I have modeled all analog filters, including the elliptic anti-aliasing filters. I haven't looked too closely at the analog effects of the hardware yet. But it's all NE5532 & TL072 op-amps and I wouldn't expect any "special analog sauce" from it. The vintage-button currently quantizes the reverb samples to the original bit depth of 16bit.

Apologies, I misremembered what you wrote:

"the plugin is equivalent to a perfect digital circuit. While I have not yet measured the clock stability of my own hardware, it's 40 years old now and I would assume there to be at least a bit of jitter and drift
analog effects like distortion, component tolerances, component aging etc. are not modeled in the plugin"

That's great that you did the entire circuit. I'm going to have to buy it! Demo's sound really good, you did a great job.