07 December 2012

Amps: Vox Night Train + NT112 cab


Before I've got any real tube amp and, while I was trying amp models in multi-effects pedal boards (as the Line6 Pod X3 Live) or in plugins (as IK Multimedia Amplitube 2), there were some models of amps that I really liked, specially in clean and, Vox AC30 was one of them.

I had the opportunity to play an AC30 in a friend' studio and, yes, its a great amp but, LOUD has a hell and, weighty as an elephant. I couldn't imagine transporting such a best from home to any other place and, either not inside my home, any way.
Other issue was the price tag. UK Made ones go really high and, I didn't wanted to have a big sounding elephant at home so, I've decided to go for some little brother in Vox catalogue.
I was really happy when I've saw the announcement of the new Night Train and, liked everything about it, the size, the weight, the price, the sound and, even that odd look. So, I've decided to give it a try.


Well, this people of Vox knows how to present their products. The take care about each single product. Cables come in an useful fabric bag, Wah comes in a plastic bag with a handle (nice and easy to transport), and this amp comes in a nice padded soft case that you can hang on your shoulder like if it was a video camera.

The cab comes inside that padded case, protected with a plastic film and, includes a cheap speaker cable and the mains cable, as well. The handle of the amp's head is over the top of the case so, you can choose to carry it on your hand or in your shoulder.

The Head is weightier that it seems. The little size of the head makes you to think that will weight not so much but, the big transformers used for this baby weight a lot, they are really good dimensioned.

The look was stunning. This little amp, together with Orange's Tiny Terror were the ones starting that trend of lunchboxes-like heads. But, the look of the Night Train was really closer to a lunchbox than the Tiny Terror, that looked way moderner. Nowadays, we are very used to this look but, that was really special when I bought it.

The amp loads a pair of Sovtek 12AX7-WA tubes in the preamp and a pair of Sovtek EL84 in the power amp. The cover is easily removed unscrewing the 10 screws that stand it. Once removed, the access to tubes is clear and a child's game to swap tubes.
Probably, the weakest part of this amp are the holes for those screws, that tend to wide after some screws and unscrews, leaving the corresponding screw loose but, after 3 years (with intensive tube swapping tests), the cover still remains in place and just one screw came loose.

Rest of parts are of quality, beginning with the input and output transformers and, following with jacks and knobs. All work flawless and are solid. Switches aren't that kind of cheap Chinese ones but, sturdy ones.
The surprise was to look to the label and see that the amp was MADE IN VIETNAM!.
Well, I have to say that it's really good made and, I have no complains 3 years after.

The cab is surprisingly small and weights less than the head so, you can easily carry on your hand. All together makes really easy to transport head, cab and your rest of rig in a single trip and, without compromise your integrity.


This is a very simple amp and, that's something that I love since any little change in their tubes is immediately noticeable. It has just a single channel, but with tricky modes that provide this amp with a high versatility. It has no FX loop but, it takes practically good all the pedals I've throw in front (some very few exceptions).

In the front panel, we will find:
  • The input jack
  • Mode switch: thick or bright
  • Gain knob, to select the gain of the preamp section
  • Volume knob, to select the loudness of the power amp
  • Tone stack: treble, mid, bass
  • Bypass switch: triode / bypass / pentode
  • On/off switch
In the back panel, just two speaker outputs, one for 8 Ohm and the other for 16 Ohm.

The combination between thick / bright modes and pentode / triode modes gives four very different amp sounds to this head, that can be rounded with the help of a very responsive tone stack.

Using it

The amp delivers about 15 W RMS in Pentode mode and, about the half (7.5 W RMS in Triode mode).
The amp is cathode-biased and therefore, needs not to be re-biased when swapping the tubes.
EL84 tubes are really affordable and there are good new production ones to test so, it's an amp easy and cheap to tweak and maintain.

The Pentode mode uses the full power of both power tubes and delivers an strong and bright sound. The Triode mode doesn't includes the two additional control grids of a pentode tube and, lows the power to half but, also changes the nature of the sound, giving a warmer and silkier (think on Class A) sound, absolutely tasty.
The Thick mode bypasses the tone stack (so, your treble, mid and bass controls make nothing) and, delivers a pure tube-like sound that resembles the sound of the good old vintage amps. Also, the gain is way higher there and it's quite easy to achieve overdrived sounds, with lot of sustain but, always very natural and harmonically rich sounding.
Every combination worth a try and have its use.

Behind this amp is the hand of Tony Bruno (a great boutique amps maker). The history seems to be that Tony designed the amp, point to point and, it's design was then translated to cheaper components and a PCB board, to reduce the cost of production and then the final cost for the buyer.
But, the soul of its design is there and, the four different modes make this little amp a very versatile one, specially for home or studio applications or, where the amp will be miked and routed thru a mixing board.

Triode mode can be very quiet for gigging, IMHO but, it's so sweet sounding that gives excellent Blues / Hard Rock tones.
Bright / Pentode mode gives you the classic bright and chimmey tones of Vox, with beautiful and crystalline cleans and, with a nice crunchy break up, when drived hard. The amp is LOUD enough, don't be fooled about their 15W. A 50W amp is just -3dB quieter than a 100W amp and, a 25W amp just -6dB quieter than a 100W amp so, the NT is about -9dB quieter than a 100W amp and, -6dB quieter than a 50W amp.

The NT112 cab mounts a Celestion G12M, specially designed for this amp that is very efficient and, projects the sound open and loud. I'm still impressed how good and high can this little cab project the sound, being so small. With good tubes, this little cab shines in a way that you will never expect for its price and size.

I've tested it with a band, 2 guitars, 1 bass guitar, 1 drum kit, 1 singer and, they said that it was sounding really loud. I've tested it in a little venue, little local, little people, without miking it and reproducing the backing tracks thru a 300W PA and, everything sounded really good.
So, despite of its size, it can do a great work.
I have tested it also with a 2x12" Cab (the powerful Orange PPC212) and a 4x12" with Celestions V30 and, of course the loudness increases significatively so, there is always a way to make it useful for each situation.

Tube Swapping

Even that with stock tubes the amp sounds good, you will never know how good can really sound until you swap, at least, the two pre-amp tubes for something better.
Sovtek 12AX7-WA tubes are the worst tubes, from a sonic-point of view, that you can load in an amp but, they have very low noise, very low microphonic issues and are cheap and consistently produced, what makes them a natural choose for amp makers (together with JJ's).

Any NOS tubes there will do an excellent job but, also lots of new production ones will work awesome and will give a great amplitude, definition and character to the sound than the stock ones.
Even the cheap JJ ECC83S will be one step over those.
You will start to notice a nice improvement with a couple of EH 12AX7 and, to my taste, the best you can throw there (new production) are the Mullard 12AX7 reissue.

Or you can choose the 12AX7 of your like (a Tung Sol or EH or JJ) for the first tube and some NOS Philips 5751 for the second tube, or a new production EH 12AT7 (long plate), or a NOS 12AT7 or a Mullard 12AX7 reissue.

With that change of preamp tubes, the Sovtek EL84 in the power amp will sound nice, since they are very well balanced and break up with a nice distortion grain. But, the Sovtek are a bit monodimensional and project the sound in a very centered beam.
Just swap those with cheap JJ EL84 and the amp will rowl like a tiger. I like those while clean but, I don't like how they break up but, without any doubt, are the powerfullest of new production EL84s.
The TAD EL84-STR is quite similar to the JJ but, less powerful and with a different EQ. I liked it more in this amp, since the way as it breaks sounds more natural to my ears but, both are in a very similar ball park.
The Mullard EL84 reissue is my personal election for this amp, since they are the ones with a greater 3D projection of the sound (with a wide beam), are very linear, very plain EQ'd and they go better and better the more you push them, with an incredible definition note-by-note even hardly driven.
I loved the sound of the Genelec Gold Lion EL84 a bit more but, those tubes are really weak and stand just few hours and, they are even expensiver than NOS tubes so, it makes no sense to buy those.

After tube swapping, I never had the need to change or upgrade the cab. I think the NT112 works really good paired with this amp and, just a tube swapping puts everything sounding as it should. And, that cab is cheap enough so, you can get head and cab for a funny price (taking into account that we are talking about a tube amp).


Well, that little lunchbox is appearing in many of my own videos but, there are some that are specially dedicated to this amp. The following one it's a travel along the several sample setting that Vox has in his site and, it's useful to check the different voices that this amp can deliver. Sorry, the guitar was so close to the recorder that there is a lot of feedback about the "acoustic" unplugged sound of the guitar.

But, this is one of my preferred demo (not mine):

And, if you are interesting on how different tubes sound in this amp, here you are the series of videos that I did while testing the different tubes for each position.

04 December 2012

Wiring Diagram: Hermetico's LP Exchanger mod 2


Guitar Modded

Gibson Les Paul

  • HH Pickup layout (4 conductors)
  • 1 Swiftcraft 3-way toggle switch
  • 2 volume pots with pull/push
  • 2 tone pots with pull/push

Difficulty Level



  • Provides standard LP combos, plus a high variety of other combinations.
  • Independent volume and tone for each pickup.
  • Enhanced version of Jimmy Page's wiring design
Wiring Diagram

Click on the diagram for a full sized view.


Jimmy Page's wiring mod achieves a lot of different combinations but, in my honest opinion, it does it in a way that isn't easy to recall and, some of the combinations produce just silence (the guitar shuts up).
The Exchanger 2 mod is my own take around the Jimmy Page's mod but, making controls easier to map in your mind so, you will be able to easily achieve exactly the combo you were looking for.
Each Tone pot splits its corresponding pickup.
Neck Volume puts Neck pickup out-of-phase (changes polarity).
Bridge Volume puts both pickups in series, overwriting the 3 positions of the 3-way (instant booster).
But there are some tricks hidden under this design.
Default, NT splits the neck pickup to outer coil but, if you have also BT up, selected coil is inner, instead.
Default, BT splits the bridge pickup to inner coil but, if you have also NT up, selected coil is outer, instead.
Also, the NV (neck volume), when changing the polarity of neck pickup (OOP) is reverting which coil is split by the NT pull/push.
In this way, we are achieving one more unique combo than in JP's wiring mod and, the best of all: there is no combo that can accidentally shut up the guitar!.
Click on this picture to see a full size of the list of combos:
In red, unique combos (that appear at least once in that list).
Notice that when the serial switch is up (BV = Bridge Volume), the three positions of the 3-way toggle switch have exactly the same combination. Once you push down BV, whatever the combo that was before in the current position comes back.
By example, imagine we had BV = down, NV = up, NT = up and BT = down and we had selected Rhythm position, we should have selected Neck Inner Coil but, once BV is up, we are having Bridge humbucker in series with Neck Inner Coil Out-of-Phase.
Imagine that, while in series, we change to Treble position. There is no change in the sound, since we are getting the same combo but, once we push down BV, we are getting Bridge Humbucker, instead.
As in the case of JP's wiring, volume controls are independent and allow you to mix both humbuckers at your taste but, when both pickups are in series (BV = up), both controls are also in series so, rolling off a bit  one will also reduce the overall volume and, totally rolling off one we will shut up the guitar. In this case, the neck volume acts as some kind of master volume.
In the middle position (and in parallel, BV = down), you will achieve different nuances by mixing each pickup at different levels, since some frequencies will be reinforced while others will be dimmed.
Also, when in middle position and out-of-phase (NV = up), the different volume levels for each pickup, will give you different textures of the out-of-phase sound (Peter Green's mod), some are edgier, some are more subtle.
Just experiment with all this.