vox night train series

 

vox night train modifications

  The Vox Night Train series is a fist full of tone in a compact all metal head design.  Built like an armored car for a tube head, peering into the head’s chrome diamond shaped ventilation scheme one can view the warm orange glow of the tube filaments stimulating the electrons milling about in their vacuum rich glass surroundings.  Classic Vox tone, but there is always room for improvement.

  I really like these nifty little heads!  They pack a huge punch and have character all of their own.  But there are some things that bother me about them.  Both the Night Train 15 watt and the Lil’ Night Train 2 watt heads have their own separate issues although very similar in design.  So, after spending some time with them and careful analysis of their design, I developed some improvements to enhance their tone. 


  First, although it has nothing to do with the amp’s tone, but why would Vox design such a gorgeous head that is so aesthetically pleasing until you get to the god awful dull red pilot LED?  Cost I’m sure, or something got lost in translation.  This is the first thing I changed on mine and for many of my customers.  I prefer blue, but I have put in pink, orange, purple, and white to name a few for my customers.  Sounds petty, but what a difference it makes in appearance!


lil’ night train


  The Lil’ Night Train is a 2 watt “HO” scale of the Night Train family.  This compact powerhouse derives its power from a 12AU7 tube and two 12AX7 tubes in the preamp section.  This little puppy sounds great in the store, but sounds a bit “different” once in a quiet home/bedroom environment.  Most owners complain of the ear piercing highs and not so stellar base response and it’s just a bit sterile.  The amp is riddled with 1/4 watt metal film resistors and cheap coupling and EQ capacitors.  Metal film resistors are great in the first preamp stage as this is the most important stage where any noise should not be introduced.  Not to overstate the obvious, any noise present in first preamp stage will simply be amplified throughout the amp resulting in a very noisy amp.  Keeping that in mind, metal film resistors are also great for transparent Hi-Fi audio reproduction, but where is the character it that?  There are so many factors that develop great tone: pickups, the character of the wood of the guitar, amp design, cabinet, and speaker just to name a few.  So we want character... not transparency!  This little amp needs some warmth and character provided by quality components historic in guitar tube amp design.















 

  Another request I get a lot of is the amp lacks adequate clean headroom.  A tall order from a 2 watt tube amp, but some decent clean headroom can be achieved at the cost of loosing some gain.  This can be accomplished by a plethora of different tube configurations.  I have my favorite combinations for what tone I’m trying to conjure, but everybody’s style is different.  Most playing styles are obtainable... within reason that is.  


 


    





 








night train 15















 

  The Night Train 15 is the fat kid or the “O” scale in the Night Train family.  Being fat in this family is not a bad thing either.   Its heavy-duty iron (power and output transformers) are to be respected as it is clear that Vox wanted to add a lot of meat and potatoes here.  An interesting observation is both the Night Train 15 and Fender’s Blues Junior are 15 watt amps powered by two EL-84s power tubes in the output section.  However, the contrast between these two amp’s iron is rather stark.  The Night Train 15 looks like its iron came from a Marshall 50 watt amp, where the Blues Junior iron looks like is was borrowed from a 5 watt Fender Champ... just an observation.


 














  Unlike the Lil’ Night Train, the Night Train 15 is loaded with what I like to call “compromise resistors.”  These would be carbon film resistors.  The carbon film resistor is a good compromise between the classic noisy, untrustworthy, yet mystical carbon composition resistor and the precise, sterile, and transparent metal film resistor.  Both of these resistor types have their place in guitar amp design, but come with trade-offs.  Vox opted to venture down the middle of the road with carbon film (Compromise resistors) in this amp.  Which strikes a good balance between the two extremes.  However, they are mostly 1/4 watt resistors which adds thermal noise since some key resistors should be 1/2 watt.   Again, looks like something was lost in translation here.











  

  Populated mostly with 1/4 watt metal film resistors and cheap capacitors in the signal path, the amp stands a lot to gain with some key component upgrades.  Too much gain and little headroom?  Different tube configurations is also key to getting the right tone out of the Lil‘ Night Train. 

After all of these refinements, the Lil‘ Night Train is warner and sweeter sounding than before.  Wealthy in guitar tube amp character, it is perfect for recording and late night practicing and sounds fabulous in the bedroom environment and as a stand-alone amp!  


  Tip:  Run this little Hot Rod through a well broken-in Fender Pro Junior Alnico 10” speaker in a tweed Pro Junior cabinet and brother... you got tone!

  The Night Train 15 is a powerful flexible head.  Unlike the Lil’ Night Train, this heifer sports: 3 band EQ, switchable pentode/triode power, standby switch, and more output power options -- 5 or 15 watts.


  A head of this caliber should should also sport foot-switchable for the Bright/Thick function.  The stock Night Train 15 does not.  However, I have a solution for that.  Depicted left is the B5 Amps modified Night Train 15.

  Check out the iron on this over-designed Vox offering.  With iron like this, one can take comfort in knowing their tone will not be influenced by the nasty artifacts associated with anemic output and power transformers.  Mass like this yields deep articulate low-end and all the clean headroom you can squeeze out of a 15 watt amp.  

  There is endless debate over which type of resistor will yield tone oozing character and nuance.  That debate will certainly not end here, but if you look at the modified Lil’ Night Train pictured left, you will notice a carbon comp resistor residing right next to its mortal enemy -- the metal film resistor.  As mentioned above, the carbon comp is untrustworthy but has mystical tone shaping qualities at the same time.  When placed in strategic locations in the amp’s design, the combination of resistor types work quite nice together.  In fact, rather harmonious.  They add a blend of traits and flaws for a composite signal that really lends character to the tone and amp.  Which is the goal here as we want out tone to be unique and not mass produced.


 

Carbon composition and carbon film resistors can sound great together!

E-mail: b5amps@me.com for more information and to inquire about getting your Night Train 15 or Lil’ Night Train setup for a smoother, warmer, and sweeter tone -- not to mention some much needed switching!

  Like the Lil’ Night Train depicted above, the Night Train 15 stands to improve by some resistor cross-pollination as well.  A few carbon composition resistors peppered in the mix brings a bit more character to yet another mass produced amplifier.  The unpredictable drifting value of the carbon comp resistor works well with the carbon film resistor.  This resistor combination yields a more complex tone character when properly placed in the overall circuit design.


  What this amp really needs more than anything -- is some automation during performance!  It sure would be nice not having to stop playing just to switch between the bright and thick voices.   The Night Train 15 seems like it’s a two channel amp, but it’s really not.  It’s a single channel that is just voiced differently -- really differently.  With 15 watts of power the Night Train 15 is a pretty decent gigging amp.  Add thick/bright switching automation and it’s a solid platform for performance.


  Enter the B5 Amps Night Train 15 Switching System.  The system installs neatly into the Night Train 15.  The system consist of switching module and  footswitch that connects into the back of the head via a installed footswitch jack.  I just finished the prototype and is currently in production for sale as a kit or the head can be sent in and installed by myself.  The switching systems sports some pretty sweet attributes:


  1. -Battery-less detachable compact rugged footswitch with bright LED indicator

  2. -Front panel bright LED indicator

  3. -Front panel toggle switch that is defeated when footswitch is in use

  4. -100% pure analog switching 
















  The Switching System will be available soon.  The cost is to be determined.  The kit will obviously be cheaper, but there is some labor involved for installation.  Once the production materials are completed I will update this page with kit, installation, and modification service prices.

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