Marshall Plexi VS Neural DSP Quad Cortex

4 months ago I reviewed the Marshall SV20 20 watts Plexi. I loved this amp so much that I had to order one. Since ordering one my Neural DSP Quad Cortex turned up and I've been using it for the majority of recordings in the studio. In this video, I see if the Neural DSP Quad Cortex inbuilt plexi tones can compare to the real thing. The Studio Rats are core band members Paul Drew on guitar/production/mixing, drummer James Ivey and Dan Hawkins on bass. They collaborate with singers and musicians to produce radio-ready songs.

[@ignaciogiss2315]

It's amazing how good and up-to-date the amp sounds with a 60 year old design.

[@joeedbkk]

The capture sounds identical to me, that Quad cortex is an impressive piece of work. Your channel is one of the best guitar channel out there and you deserve more subscribers. I'm really enjoying your videos.

[@TheStudioRats]

Cheers Joe, much appreciated

[@michaelwirth6843]

What are you talking about?!? The Plexi sounds like a real amp, QD doesn´t!

[@jeremyedwards9304]

@@michaelwirth6843 you’re gonna tell someone what they hear lol

[@guitarlair]

@@jeremyedwards9304 it sounds close but the Plexi is def fuller on the low/mids, if you can't hear that you're tone deaf .

[@mattgilley8789]

Please, please post this capture in the app. Sounds killer!

[@physiciansplaza6557]

EXACTLY what I was about to type, I see a great many beat me to it lol

yes please. Post it

[@affair2k]

Yes...I am thinking in buying a QC, and if I can have this sound, It's a no brainer for me.

[@BenLubin]

Sounds phenomenally close. Amazing technology.

[@ValNanovsky]

Dude, this is one of the most complete and accurate comparisons I've seen. Fantastic job! Really appreciate all the work you have done!

[@TheStudioRats]

Cheers Val!

[@VictorAxelsson]

just wanted to say that in my opinion you have the best guitar tones on youtube, it’s amazing how good it sounds in every video you make. Clean tones and distorted tones, all sound so good. Love the quad cortex vids! Planning on buying one so it’s super helpful :) ps. your playing is ofc super awesome as well

[@TheStudioRats]

Thanks Victor!

[@paulcasilio1119]

Paul: "I hope you got something out of this." Me: "Every time, Paul. Every freaking time. Thank you, man."

[@TheStudioRats]

Thanks Paul, I’m glad you do.

[@cleverdood]

Those both sounded amazing! I doubt you’d be able to tell them apart in a mix, but holy cow did they sound fantastic!

[@TheStudioRats]

Cheers Jason!

[@danielbertola7868]

The comparisons of the capture to the real thing always impresses. Its hard to compare when sitting in the room but listening objectively, the QC is unbeatable in the modeling world at the moment.

[@EricMarinko]

Wow the capture was really good. Great sounding amp! I'm not really sure about the model comparison though. It seemed the real amp was noticably louder, so loudness bias is a factor when trying to subjectively judge it.

[@johns4751]

Great comparison! It’s remarkable how close the QC can come to the real deal, particularly in the hands of an expert operator.

[@TheStudioRats]

Cheers John, that Marshall amp is so good.

[@bogg4n]

That capture sounds great! Will you share it?

[@ThatIrishCowboy]

Wow! When you said " that's getting close" I busted out laughing because that was so accurate as soon as you tweaked the EQ. I love my quad cortex. My main distortion right now is a capture of a dumble I found paired with a klon centaur and boosted by the utility gain. It sounds phenomenal. With the QC I now have a dumble, klon centuar, mezzabarba trinity, driftwood, and even a wizard. That's like $200k worth of amps and pedals that sound exactly like the originals.

[@IvanBassist]

The Neural Capture sounds pretty damn good, but that Plexi sounds awesome! I recently ordered a QC. Looking forward to testing it with bass :) Great video!

[@SlinkyT82]

Excellent tone and playing, that lil plexi just kills! Played through one once and was blown away. Love the comparison with the QC, def sounds really cool and will hopefully get even better with updates. Cheers!

[@06szymonszymanski]

Sounds really good but real thing wins for me. Great comparison, thank you 😊

[@TheStudioRats]

Agreed the Marshall is definitely top.

[@IvanXman]

DSP is the future. They will get more and more powerful and there will be the point when you won't need tubes anymore. In fact, tubes are the outdated technology (last century/millennium) that requires a lot of electric power, produces a lot of heat and not really reliable:)

[@jaimemonroyofficial]

Yes, definitely real amp wins, QC sounds good but it is only that, sounds good.

[@IndyRockStar]

i have the Helix. I love the Helix, but compared to the QC it's like having an Epiphone LP to a Gibson. I ordered my QC from Sweetwater (only seller in USA) and I was told I'd get it by September sometime. For only $1,849 it beats a Kemper or AxeFX by a mile.

[@TheAtticus82]

Dude, this sounds insanely good. Nice work!

[@jorgeleonel6663]

Excellent experiment/video, Paul! I was looking forward to this!! Thank you

[@TheStudioRats]

Anytime Jorge

[@thebassshopbsas]

The best video comparing quad and a real amp so far.

[@TheStudioRats]

Glad you liked it

[@NikolausBrocke]

Very professional and focused test. Thanks. Subscribed.

[@MrFafnirsgold]

This is the Best video I ever saw in comparison of a real amp with a digital amp. I make every bet. In a Blind audition I would find out 100% what is the valve and what the DSP. Even if they are becoming better you cannot make something better that is perfect in building out the tone. In dynamic, attack and response. Brilliant. Thanks. One thing in advance i am messing in every comparison dsp vs valve. How dsp reacts when decreasing guitar volume and how a valve amp reacts doing the same. In my opinion this is one of the Main differences

[@Utubesup7890]

I’ve had both and amps first and pedals. But the quad wins in all areas. It reacts when you lower the guitar’s volume. The Kemper sounded like a cocked wah when I’d lower the guitar’s volume. I couldn’t wait to sell it for many reasons. Many reasons. The feel. It need da pedal to help it with sound and feel. Ui was awful. Rig manager a pita. I don’t want to be tied to a computer myself.

[@andrehughes1]

The plexi sounds better in every way. Will the audience notice, after eq and chorus and delay and processing? No. That makes the Quad Cortex worth it.

[@IndyRockStar]

For me the Quad Cortex is a chance (probably my only chance) to have a $100,000 dollars in amps without actually having to buy them. It's so close that most cannot tell the difference in blind test. I think the main difference you're hearing is the volume. People have a built in bias to automatically think louder is better.

[@intargc]

It's not always 100% about the audience. In most instances, the audience won't care if you're playing through a 1992 Line 6 solid state amp. They just want to hear the rhythm and the vocals of the songs they like. As long as it's there, they're usually happy, barring few people that can really discern the differences. Your amp and guitar have a very clear and defined relationship that involves more than just "does it sound like that amp I like." The amp provides character, feel, and response. These things are what inspire us to play certain licks, rhythms, styles, etc... So pick the amp that inspires you the most based on all of those characteristics, not just "omg people that don't play an instrument will never know the difference."

[@Utubesup7890]

@@IndyRockStar amps are always better and depending on the amp they take pedals better but… this is the best modeler I’ve ever had in feel, sound, UI, no computer needed just a cell. Compact and cool factor. The plug in whiners don’t realize neural already put a lot of those captures in there already. The whiners just don’t want to put out the money or move away from their computers. Meanwhile, the people that literally have signature plug ins are using the actual quad on stage. Pro or not, I love it.

[@Nicolae8607]

Please post this capture in the cloud sound amazing. Thank so much..your videos are very educative and cool tones🤟

[@TheStudioRats]

Hi, thanks so much. Will do.

[@DropDee44]

@@TheStudioRats So whats the cloud name? :D

[@dreamscuba]

Great video and comparison. I have a QC and this is the closest I will get to having a plexi. You got the QC sounding very close; the capture was even closer. I am very impressed with the QC and yet it reminds me what a phenomenal bang for buck the Boss Katana is, which I have. Thanks Paul! Oh, your Goldtop is so lush.

[@TheStudioRats]

Cheers as always Scuba

[@nicholaslee2442]

Thanks for the awesome video! You really answered the whole tube vs digital debate inadvertently. But, the cortex is an insane value for all the things you get. I hope to own the cortex for my main recording tool and an sv20 just for my personal pleasure

[@TavaresProject]

That capture feature is a beast!!!!

[@zeluizsn869]

I'm a new user of the QC. This comparison was really good. Subscribed to your channel.

[@stevewoodzell415]

Thanks for the great video, super useful! Am pretty much sold on getting a Cortex for live use

[@CoreyWitt]

Not sure if anyone else has asked this, but I'd pay just about anything for a Kemper Profile of your SV20 through that db13 cab. I used to have a similar rig, with the handwired Marshall 2061x into the exact same db13 cab. It's so great. Thanks for posting this!

[@LeoAmuedo]

Love your channel !!! Great playing as well !

[@TheStudioRats]

Cheers Leo.

[@NJ-Tech]

Any chance of uploading that capture to your QC cloud? If you dont mind of course, thats a wonderful tone!

[@irishRocker1]

The model was similar but the capture was spot on! Specially having seen the model comparison first, when you hear the capture comparison it was like wow that is what you were aiming for but could not get with the model. It was interesting to see you add post eq to get it closer though.

[@Geetarhed]

Les Paul plus Marshall = tone heaven, great channel!

[@TheStudioRats]

Cheers Rob.

[@NevermindTheNirvanaTributeBand]

I'm capturing one this weekend! Thanks for this!

[@TheStudioRats]

Nice one, let me know how it goes.

[@BenJ2827]

QC is on my shopping. I have the SV20 combo and with an SD1 in the front it’s the best sounding aggressive rock amp I’ve ever owned! Amazing amp.

[@TheStudioRats]

Nice one, cheers Ben!

[@SuperEr90]

that sound capture was impressive good!

[@Ningishzidd4]

Wow, great playing. Such a rich sound.

[@DougErapps]

the Cortex gets close but has a persistent blanketed (blanket over the speakers)/slightly- muffled tone. Missing the openness of the actual amp.

[@jayl5941]

Another fantastic video. That is one great sounding little amp.

[@TheStudioRats]

Cheers Jay, yep that Marshall is killer

[@qualaup]

Awesome capture Paul!!!

[@nigel900]

Fantastic! 👍🏻 Me got a Marshall Plexi 1987x, but me want the Quad Cortex too…

[@jonathankrieger9121]

Will your capture of the Plexi be available for other Quad Cortex Users?

[@Nicolae8607]

OMG I want this QC so bad 🤟 Thx for the video,always a lot to learn from them.

[@TheStudioRats]

Anytime Nicolae

[@physiciansplaza6557]

just got mine after waiting 6 months, worth the wait. Now if I can just figure out how to use it

[@Johnmannish]

Amazing. Please make a DI capture of that amp and share it so i can use it with my cab, please!

[@physiciansplaza6557]

I second that notion!

[@TechnoRiff]

Nice comparison. I think with a bit of EQ tweaks, the QC could sound even closer to the Plexi.

[@stevenf7474]

Capture sounds great!!! Are you going to upload it? It would be great :)

[@Paul-D]

I really paid close attention here, great headphones etc. and I think that SV20 here absolutely ruled the day, They way you recorded it (what mic did you use btw?) just caught everything I love about that plexi sound - although id of had a little less drive haha. The neural is awesome too.... but it sounded so 2D compared to the bloomy natural fuller sound of the amp.

[@imagzz4942]

I hate when people talk about latency because it's literally all placebo. It's something you think is there but isn't. Like, your brain literally can't notice a difference. The QC is so fast that it doesn't matter. Do you notice a latency when running through pedals? No. Do you thought modellers (especially newer ones like the QC)? No, you don't, because you can't. So the "latency" that you "feels" is just something you're imagining. I'm not saying it doesn't sound difference or feels different or that it's better or worse, but I'm just saying that you aren't actually feeling any latency. Besides, we have to remember that most of what you're hearing from the Plexi (at least EQ wise) is probably duo to the the cab.

[@TheStudioRats]

Unfortunately it’s fact, latency exists in digital equipment because of the processing that the unit has to do, There is no getting around that. Weather you as a player can feel it or not is down to the guy behind the guitar.

[@dutelatte2154]

Wow when you capture the sound it's really amazing, when you are just making the sound I don't think you can get a good one as much as when you capture it, the less versatile thing is knowing that after capturing you can't change any parameters.

[@SomeDudeDan]

Awesome! Could you please share the capture of this amp on the Cortex mobile app? Thanks in advance!

[@TheRickdoggie]

Great video Paul! Hard to beat the real thing! But you matched it really nicely.

[@TheStudioRats]

Thanks 👍

[@Nghilifa]

Sounds effin great! If you hadn't pointed out which one was which, I prolly wouldn't have known myself. As far as sound quality goes, the digital stuff is right up there. I haven't tried playing one myself but I suspect (like you said) that the experience of playing through one is different from the valve/tube amps that we all know and love. I might have to enquire Santa about a QC for christmas 🤔

[@TheStudioRats]

Cheers Ricky

[@jspmusic7938]

Hi Paul, is there a possibility you could upload the capture on the Cortex Cloud? I am just in love with that sound..

[@DidiHyena]

Nice Video👍 You said it...you feel the difference by playing...something is for the bedroom, something to get the power... real men play Marshall🤘 stay tuned and keep on rock'in

[@VladiVladiG]

Hi, great comparison and great tone matching. Do you happen to have the capture of your amp on the Cortex Cloud? If so, let us know which one it is. It sounds bitchin! Thanks!

[@jasonkerr931]

Can you post this capture on your profile in Neural Cloud? What a tone!

[@paultozz928]

WOW. VERY INFORMATIVE I still using a pod hdx 500 with great results. I will upgrade soon It's at the end of it lifespan after 6 years of gigs.Gigs beat up gear on the floor

[@Utubewrk123]

Put it higher up. You can’t compare that hd500 thing. I had one. It was awful. Actually a lot of the pros are using it on the floor. I’ve seen some bands have them on metal slides out of a metal cabinet. But the foot switches will hold up. You can’t protect a pedal board either on the floor.

[@deanhewlettguitar5119]

Sounds amazing. is capture uploaded? I can't see it on the cloud Cheers Dean

[@tonepilot]

You really need to match the volume levels. At least at the beginning, the real amp was much louder. Also did you add reverb in post?

[@TheStudioRats]

There’s always one person that complains about levels. it’s impossible to get an amp to stay the same level as the comparison amp throughout a video while adjusting the parameters.

[@tonepilot]

@@TheStudioRats It’s a known fact that louder music tends to sound better. Can’t recall the term. So i’m being labeled a complainer because I thought the volume levels should be closer? That’s a bit judgemental when what I was suggesting was a fair comparo. Oh well, life goes on.

[@tonepilot]

Fletcher Munsen curve I think?

[@szymonszymanski3]

Hi Paul, could you upload this to the QC cloud please?

[@laz288]

Having owned most all modelers even from day one with AXEFX I they all still have a weird scooped kind of cardboard sound. For gigging 100% no brainer they are great, for recording if you find a new sound and use it for the sound its great. To try to reproduce a tube amp, they are close but never there. They seem flat compared to a living breathing tube amp.

[@m00se67]

i do agree there is something off ..like a papery sound almost ..But putting my helix through an orange pedal baby into a cab ..it get rids of that but then i guess we are not far from using an amp,,but i do find it more convenient

[@Utubewrk123]

@@m00se67the helix and Kemper are gone. I love the quad. No it’s not a great amp but it’s pretty close as far as modelers go it’s the best I’ve had.

[@MacGregor88]

I notice there is reverb and delay on the Cortex, where is that coming from? Are you using any other external gear that is affecting the sound?

[@rylovengeance]

Pleeeeeeasseeeee post this capture!!!

[@guitarlife6190]

When you did your capture did you use a load box or did you mic your cab straight into the Cortex?

[@pabloc9869]

Amazing Job 🙌🏻

[@fftbbald]

Please share that capture!

[@mightymikeamps9317]

Is your signal chain guitar>A/B switch> Marshal or QC > interface?>DAW with Delay and reverb Or are you getting your delay reverb and mic pre somewhere else? Also do you use any compression? Sorry for the million questions, but you have such a consistently high quality tone no matter what you use, and I really want to improve.

[@eoinc4091]

Hi Paul, thanks for the vid! How does the Studio 20watt compare to the Plexi 1959slp ?

[@jeshuabenson12]

amazing video!! i'm now convinced to buy myself a quad cortex! will sub to you as well! God bless!!

[@eoinc4091]

8:09 I remember what computer games sounded like that 😂

[@zoomzoom3950]

Having the real amp you like is great for AB comparisons for modeling. Most modern modelers can get close, except the feel.

[@Utubewrk123]

I agree. I love my amps and pedals but the quad is the best feeling and sounding modeler out there right now. With the best UI. I’m glad I’m no longer tied to a computer as well. Amps will always come first though with pedals as I’ve said.

[@zoomzoom3950]

@@Utubewrk123 Still have and buy tube amps, and if I could actually use them as designed I'd transport them. I've owned many modelers including Vox, Boss, Fractal, Line 6, they all were good at the time, but like most technologies they continue to improve in many ways. My main modeler now is a Boss SY-1000. However, I'm building a small, portable wireless rig around the Mooer Prime P1, the sounds are very good, but there's very little feel. All in all, for the price and size, I can make it work. Fits in a lunchbox size carry case, with 2 wireless systems, wireless in-ears, footswitch, cables and USB charger. Even fits my Tech 21 PSA 2.0.

[@DANTHETUBEMAN]

You dialed that in vary close, you could raise the high frequency your boosting at the end. The capture sounded great. I could record or play a gig with those sounds.

[@MeTuLHeD]

Hey...a question occurred to me. When you did the capture at 9:16, how was the Cortex connected? Did you use a mic on the cab, or did you run a signal out of the amp into the Cortex?

[@TheStudioRats]

it was miced. cheers.

[@MeTuLHeD]

@@TheStudioRats So wouldn't that mean you capturéd not just the amp, but the cab as well?

[@prodantech]

I wonder how the Quad Cortex compares to the UA Lion for Marshall tones. Not just from the raw standpoint but also how the units respond to your playing, simulate edge of breakup and that kinda stuff.

[@user-pm7pw1tl3t]

i think the qc sounded better the whole time. the plexi felt coverd under a rag in a other room.

[@ryanstark9326]

Hey! Great video, so you have a overdrive on your plexi too or is that the sound direct without any effects?

[@ian2lorimer]

Nice....the capture sounds pretty damn good. Pretty close.

[@TheStudioRats]

Cheers Ian.

[@abgz1206]

Awesome. Thanks 🙏 #staysafe

[@neildeakin4454]

Bloodyhell, just ordered the DSP on the strength of this video.

[@MrNastyguitar]

Sounds like you adjusted the Plexi to sound like the Quad on the last recording you did, both sound like there was a blanket covering them, where before it was wide open and clear for the Plexi

[@CyberneticArgumentCreator]

Sounds great. Way different dynamics but the EQ and clipping are very very close.

[@kenmasters007]

The capture was sooo much better than the preset. Did you still have any of the latency issues with the capture?

[@deepestpurple]

Nice work and playing! Do you have this on the QC cloud capture?

[@robh1780]

The real SV20 20 plexi is just so perfect and delicious. I would not mind having the Neural DSP for experimenting in Studio,

[@simonecelante7729]

Great job!

[@FrallaN024]

Great video

[@Migler1]

My suggestion is to increase the mids on the cortex just a little bit to get it more simular.

[@zwip778]

Your playing is sublime. You should teach your style of playing. Did the capture also feel different under your fingers or just the modeling? I’ve just ordered an FM3 and hopefully the feel is there.

[@TheStudioRats]

Hi Anna, thanks! It still does feel different, it’s a small thing but it is there. Good luck with the FM3 I hear it’s great.

[@TheMartinRNR]

NOTHING Like a REAL PLEXI

[@edilsony2b]

Is this plexi capture available on Cortex Cloud?

[@Tone5DP777]

I think the actual amp sounds more alive. The Neural Plexi is very good, but it has that a little bit of that muted horn tone.

[@Utubewrk123]

Great stuff here.

[@jeffarowbat6385]

Great video! which speakers do you have in your divided by 13 cab?

[@evetsiksatu]

Not sure how you can be in the same room with the Marshall levels set that high--even in half power mine starts shaking the walls through my closed back Orange cab!

[@finnjeff]

I believe he was attenuating the Plexi with his Boss tube amp expander.

[@yomamaa13]

I need this capture!

[@blakjack3053]

A tube amp is like a Hemi Cuda. A digital amp is like a Tesla, both can get you from point A to point B and back again but one of them is way more fun to drive than the other!

[@Utubewrk123]

I love a great amp and a great pedal but the quad’s pretty fun to fool with and it feels the most like an amp and sounds the most like an amp regarding modelers.

[@SLASHMPI]

Love thia video

[@lukather1]

Levels different ? ❤️

[@blargh039]

Yeah, it's really hard to tell the difference between the two since the QC is at such a lower level. I tried adjusting the volume of my computer live to compensate, and it makes them sound WAY more similar. I'd be very curious to hear a corrected version of this video with the levels normalized.

[@jcradical2520]

The Quad Cortex is always significantly quieter than the plexi in your. You really can't compare tones when they're different volumes. The louder sound will almost always sound better. The whole test is invalid because of that.

[@joaov7802]

Yeah