I've had the Opus for 3 months, use it for practicing at home with a Cort B5 Element (switched to passive) and high quality headphones.
Not crazy about the provided bass presets, but relatively easy to tweak &/or build your own.
If your bass has an active/passive switch, I strongly suggest you set it to passive, or for sure set all onboard controls to flat!
That will allow you to tweak, after setting up your Presets, to taste on stage.
The key to using the bass cab modeling (I've added the Standard Powerhouse 1000 and 212, the Don Bronco Evo 115 New, and the REA One cab models off Two Note's website) is to start with the cabinet only, tweak the mics and positions, then if desired, the EQ (I only use the Custom mode) until you find a sound you like, then if desired add a Preamp &/or Power Amp - I don't use the Enhancer or the Reverb.
I mostly use the Foundry Bass and the Foundry Preamps either with or without a 6L6 Power Amp.
I also like the Aviator at relatively low gain.
I have a few good presets using the Peggy Preamp and either the 6L6 or KT88 Power Amp.
The Albion to me only works for that Jack Bruce high gain, overdriven type sound.
My favorite Presets are using the Foundry or Foundry Bass with a 6L6 Power Amp and no cabinet!
Jaw-dropping good tone.
Great pedal that is very versatile.
I gave it 4.5 instead of 5 stars because IMO, they did not give much consideration to bass players as far as a better selection of provided cabinet models.
There are a lot of cabinets you can browse and purchase - when trying them out online, do it with the cabinets only (no Preamp or Power Amp as they will color the tone).

OK. I'm used to tech both in studio and live. But this is all potential and no playable features. At first, I thought it may be me. Maybe I just needed to learn how to get this tool programed and play ready. But no, this is a total waste of time. More time fiddling then playing which is always a huge red flag for music tech. Further, great you are bringing true amp models but why bring buzz that needs to be gated? Makes no sense. In the end, a million unusable and impractical features. If I spent weeks plus, maybe I'd figure this out and get a few usable saves. But no. Not what I need to be investing time into. Sending back.

I bought this for IRs mainly, to pair with my normal black Two Notes Captor along with several amps I use. I wanted something that didn't require me to monitor through the DAW or use a VST. I use an Apogee system with an API lunchbox. It's great for silent home recording with any amp, given you already have a load box.

I also use it on a Roland JC77 amp at home. No need for load box on solid state. I use that as my preamp and run pedals into that amp, and this is at the end as my IR.

Outside that one big thing! Another great option is mixing your live analog mic sound, then sending the Opus to FOH. This is great to get a 4x12 cab sound if you have a 1x12 or 2x10 type setup. You can blend the two together.

Another great option is wet dry setup! You could use the amp sim on the Opus as a huge headroom amp sim to PA, and have effects on it, then mic your normal amp in as well with overdrive. I use a wet/dry setup at practice, but carrying all that is a lot. This allows me to throw the Opus amp sim on an A/B/Y live.

Just so many things you can do! But my favorites is a stand alone amp on the go. Also silent practice with the built in headphones, and aux in for your iPhone/PC or any audio player to practice along to. I bring this thing on trips with 3-4 pedals, and I can jam at a minutes notice. Big reason I bought one before the holidays!

If you're looking for a direct monitoring solution for IRs, Amp sims or simple want a more portable backup rig…this thing does it! I find the amp sims sound very good with pedals. A Morning Glory and high gain is really all you need for basic gigs. If you play just distorted, edge of breakup or super clean all the time…no pedals needed it has you covered! However if you use midi, you could switch between presets.

The 5150 and Fender sims are outstanding on this. Marshall sounds decent, but 5150 is the better high gain on this one imo. Ampeg is also great for bass or guitars. Also has an Acoustic sim and tuner on board…you really don't need a computer outside 1 time update. But can use your iPhone or PC if you want!

Cons:

1 star removed, as I wish it could Bluetooth to a cellphone for audio as an option. Also it would have been nice to even have a cheap audio recording feature to pc over the USB-C on the go…but would add a lot more money I assume. However, in future I think a Bluetooth phone connection for audio would be a great feature that's doable! I don't always have the dongles, and the 3.5mm cable laying around as common.

Very impressed with the Opus. A lot of different tones and options are on board with a very realistic feel for a digital modeler which is critical to me. My pedalboard setup is kind of unique with 4 options available via different switched routing options and the Opus along with a Plethora X3 for stereo modulation effects plays an integral role: Pedals>Opus>TC Plethora X3>stereo>mixer/audio interface. Pedals>amp>Opus>TC Plethora X3>stereo>mixer/audio interface. Pedals>Simplifier X> TC Plethora X3 in effects loop>stereo>mixer/audio interface. Or pedals, Plethora to front of amp. The Opus really excels at allowing me to play my 40 watt amp at lower volumes with a load box at home or jams with many different cab options. I can route everything to a mixer to FOH or at home into studio monitors and I get great full amp tones at useable lower volume. I also use the mixer/monitor setup without the amp using the Opus full set of available amp/pre-amp and cab options for an almost dizzying array of choices. The app or PC/tablet control is very useful. I also get silent practice at home using headphones from the mixer. The Simplifier X is also an analog option I use for realistic amp feel but I have to say the Opus comes pretty darn close for a digital modeler, with no latency issues I can hear or feel. Great job Two Notes!

Absolutely wonderful amp sim with sounds for days!

I love this thing now. I play bass and guitar and can get so many fun sounds - compressed or not, bouncy or not, tons of EQ possibilities, no effects that get in the way.

I spent my first day or two stumbling through presets and not liking many of them. At least half of the presets are geared towards high-gain metal and hard rock, or they're very British (Marshall and Vox), or they have a ton of reverb added. I think they're meant to make you sound like specific classic rock bands/albums/recordings. Not my thing at all. I prefer full, neutral lower or mid gain tones that clean up easily.

Once I got into crafting my own tones, especially with bass, this thing just came alive. My process was simply to choose a preset, remove the reverb and dial out most of the gain, and enhance with EQ the character that I enjoyed in the sound.

Now I love it and will probably never let it go. So many of these tones are so inspiring on bass and so very different. If I'm in a band setting and don't get "my sound" with whatever preset I choose initially, I have about a dozen others to choose from that will mostly just change the "character" of the sound in a way - a myriad of full and slightly gritty rock tones at my fingertips. Plus I get the same tone to the front-of-house.

Also, another avenue that excites me but I haven't even gone down yet... This thing can take an amp-level input. Meaning that you can run amps into it and sculpt a cabinet sound around an amp that you love. Tube amps will still need a load box or cabinet out the other end of the OPUS, but it does capture the amp sound. Very excited to try this method out for guitar.

Good job Two Notes.

This is a very cool device. It allow me to get really great amp and cabinet tones via an extremely eady user interface.
No silly frilly sounds that nmost of us never use, thank God. Just good solid amp tones. I am using it for recording and it has made the process so much nmore enjoyable. No more endless menu diving in search of a cogent tone from my guitar.
I love it! Thank you Two Notes.

Have been reading about the IR revolution for years but couldn't get near a Kemper given their price although the new Kemper stomp does have me thinking about getting one someday. However from what I learned about DynIR from my sales bud Yuval I decided to give the Opus a try (especially while it was on sale) and have been very impressed. I really appreciate it when manufacturers put the price points low enough that it's not the end of the world if a piece of gear isn't what one expected. That's not been the case here, but just saying. Oh, and the Opus feels solid as a rock. The build feel is amazing. One caveat, when I first plugged mine in I thought it was broken as the line noise was absolutely through the roof. Turns out that as-shipped the volume settings were dimed. Not sure why, but once I found the gain/volume settings and backed them down to realistic values all was well. Just FYI. Anyway, thanks to Yuval for all the help with this order!

two notes opus is a fantastic piece of gear ,there is a unlimited posibillity with this unit for making great music,
it will be fantastic for recording ................

Well, if you want hyper realistic feeling and sounding amp models with XLR out, this box delivers. It's a solid build too. I purchased this several months ago and I'm just now unboxing it. This unit is best suited as a paddleboard amp simulator at the end of an effect chain going to house or recording into a DAW. The apps are responsive and the cabinet simulations are another level. That's good. The issue I experience that was less than good is along with having realistic sound and feel. It also has real tube amp noise, levels, and the gate, while effective is not very elegant so it does not feel subtle with a light touch and tends to gate out very lightly played notes, even when set in its lowest position. I'm still giving the Op. 5 stars however. I have helix and TONEX and software and hardware versions and this goes toe to toe with it although it does not have on board effects other than Reverb. This is for a different sort of purpose. It's not an all in one solution, you need to use it with effects. I plan to use this in the studio as well as mounted at the end of my signal chain on a pedal board. I don't miss an amp at all when I'm playing through it. It gives you the tube app experience, wart, and all.

If you looking for a great product that gives you all the advantages of cab modeling at a great price.
This is your box. I love that I can connect it to my iPad to have it on stage with me.
You can change out the Cab on the fly or set it up on your MIDI. Using it in conjunction with their Revolt Guitar. You are set for the stage. now you have all the cabs and the preamp of your choice.

Love their products.
SL.

This thing is absolutely incredible. It has eliminated the need of quite a few pedals on my board while allowing me to consolidate to one board for electric or acoustic shows. 1/2 star off for lack of an effects loop.

I bought this specifically to use as a silent practice rig with headphones. That is not its strongest suit.

With a one year old at home, playing through my amp is pretty limited due to their sleep schedule. I was looking for a solution that would give me a really great model of my Princeton that played well with my existing pedalboard and allowed me to practice silently during naps or after bedtime. What I found was that I was spending my time dialing out fizzy high frequency distortion or boxiness. I tried a variety of studio and consumer headphones (Shure SRH440, Shure SRH840a, Bose QC45, etc.) and could not get a GREAT sound. It was pretty good at best, but with annoying high end fizziness.

That didn't jive with the reviews I had read. Or with the sounds I'd seen in online demos ahead of purchasing. Or with Two Notes' stellar reputation—all of which led me to make the purchase in the first place. So I did some experimentation. The line out into a recording interface sounds great. I think it's just an issue with the sound out of the headphone jack.

I do like the tweakability. The included Preamps are solid. Having two different flavors of Fender cleans available was really nice. The power amp modeling is great and adds a tremendous amount of flexibility to the sounds. Want a Twin preamp into EL84s? You might once you hear it! The included cabs sound good and the available DynIRs through their website open up a wide array of tonal possibilities—I was especially fond of the Jensen 50's set, but the BlackCream 212 sounded closest to my Princeton in the room—along with being able to select a wide variety of mics to really dial in your sound, the options are pretty limitless.

And the license they provide to GENOME, their mono->stereo DAW guitar processing software is really next level. I wasn't looking for this, but having it now opens up a ton of possibilities for my recording. (Yes, I'm returning the OPUS, but buying a GENOME license.)

What I found for my specific use case is that having GENOME on the desktop and having another smaller, less expensive solution for headphones—something that's designed 100% for that purpose—is really what I need. And as much incredible functionality as this device packs in, it's not what I was after.

If you're going to use this live as a DI, an amp replacement that fits on your pedalboard, or for acoustic IRs, you may get a lot of mileage out of it, and sound good doing so. I didn't test these things, but given what I did test I think it will do a great job with these things specifically.

However, if you're looking for a quiet headphone practice solution, look elsewhere. (I ended up with a Spark Go. Love it.) And if you're looking for something to record with, this *may* suit your needs—unless you already have a quality interface and DAW. If you already have those two things and that will be your main use case, get yourself a GENOME license and save the rest of your money for a pile of cabinet DynIRs. Your guitar tracks will sound fantastic.

I'm not sure how anyone can give this less than 5 stars. I have this as my live DI rig, combined with regular pedals, all controlled via midi. The lack of an effects loop really hasn't had any impact; I run a delay and chorus post Opus and the output of the delay into the house pa. I am glad I went this route over a full blown modeler, as I have a ton of flexibility to swap pedals as needed. Unbelievable value for the price, or any price. Highly recommend.

I purchased this pedal to mainly load dual IR's for playing my guitars and bass through monitors, and the power amp sim for adding power amp saturation following my physical preamp stomp boxes. I really was not expecting such an amazing tool. The power amp sim is really nice, and the 4 main tube types each affect my guitar tone uniquely. I think each type of vacuum tube they're modelling does a nice job at altering the gain structures of your tone without taking anything away. When bypassed and set to unity gain (for me that's having the pedal output volume at 85 and leaving it there), the pedal adds zero noise to the line, and buffers the signal on the line out which I run to my delays/reverbs. I plugged this thing into multiple 12V power sources (VERY generous of Two Notes to include a power adapter in the box) and did not notice any noise coming from the device (Voodoo Labs Pedal Power 3 Plus, Truetone Onespot Pro CS12, and a Walrus Audio Phoenix). Honestly, great device, super versatile, light, comes with micro SD card included, can function as your DI, and no major downsides or build faults. Really nice build quality as well. Can also take line or amp level signals, which is REALLY amazing, my Rupert Neve Designs RNDI is the only other device I have that can take amp load as long as a cab is connected, and that thing was $ by itself. Just buy this and save $ on a good DI. WIN WIN.

In spite of the various preamp/amp modeling pedals and such that I have, my Helix LT has pretty much been my go-to device. My wonderful fiance bought me an OPUS for Christmas and I'm very impressed with it. I run the OPUS in one of the effects loops of my Helix and control in via MIDI from my Helix patches and snapshots. The Helix has really great amp modeling built in, but I think the OPUS sounds better. It also allows me to free up more DSP in helix to run effects. The OPUS is a great device and I highly recommend it.

Compared to many other software guitar modelers, this is just way better than anything that I have tried before. Easy to use, reasonably priced, expandable, and overall just an amazing sound. Highly recommend over even UA, Softube, Guitar Rig, or Bias.

I mostly bass run direct to house with in ear monitors. Have had great luck with the Bergantino SuperPre but recently added the Opus for cabinet simulation. I'm regularly asked where my amp was in stage. Minds are blown when I show them the Opus. The Opus has great preamps as well, but I wanted to keep using presets on the Bergantino. Add the Opus to the mix and BOOM! Amazing sound. Nice to switch between 6L6, EL84, EL84 and KT88 in pentode or triode mode. Bluetooth connection to my iPad a breeze to make any changes on the fly. Fantastic flexibility and consistency. Highly recommended.

I really like this box. The presets in the included Torpedo interface are great, a massive improvement over my DAWs built in amps (both Logic and Digital Performer). My only real issue: Two Tones announced new free preamps were "available" for free download, but no matter what I do I can't seem to get the required firmware update. I have a service ticket in, maybe they'll figure it out.

Seems to work just fine with all of my pedals, and the sound is amazing.

I've already added a few new cabs and really enjoying the results.

May buy two more for a stereo board too.

I've been having issues with Opus being integrated with my pedalboard. Seems that no effect routed after the Opus produces the correct output sound. The sound is at half volume, a bit fuzzy & very compressed. A cable from the Opus 1/4 out straight to a speaker sounds correct but adding an effect and a DI does not work correctly. Seems to the the Two Notes Engineers stumbled on this one. The unit is not working like they say it should & as I have been in close contact with their team, they have not found a solution to by issue. Another thing I didn't expect was that I needed a DI to use this in a pedalboard situation. The design of this unit gives the impression that it can & should be used in a pedalboard but does not work as of now. They now have to fix this in order for me to give a better review and just maybe I will update this review.