Nux AS-4 Amp Simulator


What is it?
Nux AS-4 Amp Simulator from Nux New Analog series. Made in china in 2013. Cheapest thing there is.

These units have around for some time now, and this unit is part of family of four. There is Overdrive, Chorus, High gain distortion and this one – The Amp Simulator. The price tags raised a few questions. Could it be usable or just crap in design and build quality? Is it one of those cheap 1:1 corporate clones that flood the market from china? I wanted to find out, so regardless of the risk, i bought this one. Of course, i ripped it wide open as soon as it landed on my mailbox.


As the japanese started to use two separate boards in the beginning of the 80s, we have the same board method utilized here. The biggest difference being the 1590B-sized box instead of higher type commonly used by Boss and others. The bigger board has the effect circuit and switching, while the smaller board holds only the controls. Standard true bypassed pedal with “meh” build quality. Some ugly flux residue, but the components are baked on neatly.


The design methods are not bad at all. The screws that seal up the bottom plate are also used for fastening the bigger bottom board to the enclosure. If you’re going to build pedals in huge mass produced fashion, this is the way to do it. the jacks are screwed on to the box as well, offering some more sturdiness. The engineer behind the box design knows his stuff.


Note the wax on the picture above. Yes. It is ugly, and probably not the greatest way to secure the ribbon cable connections. It still seems better to have the wax in there than to rip the joints off accidentally. Mix of mylar caps in otherwise all SMD board in Digitech manner doesn’t convince too much…


Next up is the one biggest issue i’ve come across. The pots. While those may be 1:1 clones of Alpha brand components, they are not good. One big culprit on the whole pedal. They work – yes. But they turn way too easily – in a word, they are just too sensitive. Just a tap with your foot can ruin your perfectly tuned settings in a heartbeat. If the company didn’t “save” money on pots, i would strongly recommend these for anyone and everyone. It is quite sad. One little thing ruins a design that is otherwise reasonably good.


Didn’t go too deep on to what the design has in store. I’m just going to leave it by saying that the component selection reminds me of Xotic’s BB preamp pedal.

I’m also hoping that Nux won’t sell these things as OEM for cheapo brand boxes for their own good. So far i’m quite confident that the future of original chinese pedals lie within Nux.

How does it sound?
Soundwise too. BB comes to mind. So it’s rich in bass and warm in gain. Overall tone is pleasing and starts from mild preamp with natural feel to it – which then can be turned to soaring gain monster by turning the gain knob. The overall sound has a lot of common with good tube amps’ overdriven sounds. With versatile bass and treble controls and well working gain control, this is very usable and good sounding pedal for a good price. I’m just hoping they acknowledge the pot issue and fix it. Before that happens.. No recommendations from me. I’m going to use myself as a guinea pig and get all four pedals in this analog series. Well see then…


14 responses to “Nux AS-4 Amp Simulator”

  1. Thanks for the review. How about putting some felt washers between the knobs and the top of the case, to stop them moving too easily?

    Soft stops for the valves in a trumpet, or similar, should work.

    • That should work, but i think it’s still rather crude hack which one should not need to do. I bet they saved about 3 cents per pot.. :)

  2. Agreed. It makes you wonder how long those cheap pots will last, before they do the crackly volume knob thing too.

    I guess replacing them when that happens wouldn’t be too hard, if it’s still in use by then. Having them on a separate board should help with that – maybe easier to just replace that whole board with a home made perf board one, at some point?

    I saw one on sale, for Cyber Monday (whatever that is), which is why I was googling for reviews. I’ve ordered one, so I’ll see how it goes. If nothing else, it’s a decent enclosure for a home made pedal.

    I probably have a spare cornet soft stop or two, somewhere. I have lots of little sticky backed felt pads too.

    • Actually, those aren’t the worst pots i’ve seen, even though they are bad. You should probably just try it out and then see if it needs any attention. The pots are standard 9mm D-shaft ones, so swapping them for genuine Alphas shouldn’t be a big task.

  3. Good review. I have bought one and I must say, the pots indeed are very flimsy. When you adjust them you can feel the pots weakness. The soldering looks really good. One other weak thing is the direct placing of the footswitch on the main board. It begs for breaks in the PCB. For proff use it has to be re-boxed with good pots and free switch. The sound is not real!! I have two dozen of pedals and analog amp simulators, most own build clones of “boutique” manufacturers and some bought. I never heard such a beautifull tubelike sounding pedal. With the drive set at zero and the bass and trebble full open you hear (with a strat) a very good kind of blackface sound. Then the drive a tiny little bit up and the bass and trebble a bit back you have the tweed sound. With the drive at about 9-10 o’clock and the bass and trebble at 10 o’clock comes Marshall in the sound. When you crank the drive you will get Mesa and soldano territory! The tonestack is very subtile and I think this is a James/Baxandall kind of stack. Very good. I’ve looked on the internet for the circuit schematic but could not find it. I’m very curious how they did this. The overdrive is very warm and tuby. I have removed all my pedals and I use only this one and a dumbloid for kickin the solo’s. I don’t use a guitar amp but play straigth in my mixing console. I’m going to rebox it with quality pots and a extra solo switch. Great value. I bought this on Ebay for 23 dollar and free shipping. Wow!!!

  4. Hi, bought this Nuxas4 out of curiosity, have been using Boss Gt8 straight into pa via Peavey 10 mixer. Gt 8, too heavy, and too complicated.
    Took Nux to gig ( the only way) plugged in and twiddled a bit, what a great clean sound, and can be adjusted to break up a little with harder playing, which is what I wanted.
    I really like it, weighs next to nothing, and at £15 ( carriage free ) worth buying a spare.In one gig I achieved the sound i was looking for with the GT8 for best part of 10 years.Guitar is a 1997 collectors Edition Strat with Texas specials, will try it with my other guitars.

  5. The pedal is pretty awesome. My switch failed though, and it was not an issue with the board, but just the part. So I replaced the part and the company refunded me $10 (out of $20). The sound is great, and the distortion can get quite sick. I mean, I intend to play thrash and death metal with it and I think it will work just fine.

  6. Bought this pedal because it was so cheap, £17.00 throwaway money. The tone from this pedal is unbelievably good, at 0-2 you get a nice breakup, go past 8 and this thing roars. It gives a nice rounded tube sound, very versatile.

    I’m getting a tech guy to upgrade the pots, switch and jack input so I can gig with it. I also bought another two, because they’re so value for money.

    • I believe these are sold as a number of different “brands” as Nux seems to offer most of its line-up as OEM.

      Great work on the trace!

  7. I have one that recently has no sound. It switches on, the led turns red, I hear the sound of the master volume knob turning, but it doesn’t work. No effect at all. What could it be?

    • Number of things.. I’d try to probe where the signal dies. Since the master volume seems to work, the issue should be somewhere earlier. Maybe the signal doesn’t flow from input jack to the board?

  8. This pedal is a Sansamp GT2 clone fixed to the California setting. Excellent pedal but could use a little more high end and a little less bass in my opinion.

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