Tube Amplifier Maintenance, Repair and Mods

Some samples of my work

Workshop located in Urbana, IL      Contact Wes Howard at

weshoward@gmail.com    217-417-2080

Since I was a pre-teen, I had built electronic kits from Radio Shack, so it wasn't a great leap to start working on my own amps in the late 90's.  There are no longer any training schools to learn the art of tube amp repair and maintenance. So with the help of local tube amp gurus and the internet I taught myself.  Since then I've worked on my own amps and many local guitarists have asked me how I get such a good tone, so I ended up working on their vintage amps as well and starting this business.


I specialize in the repair, maintenance and modification of vintage (and vintage style) vacuum tube guitar and bass amplifiers.   Since they are incredibly common, I have been inside countless Marshall and Fender amps and know their circuits well.  Other brands I have repaired or modded include  Ampeg, Vox, Silvertone, Airline, Gibson,  Supro,  Sound City, Musicman, Mesa Boogie.

Amplifier Mods (this is the fun stuff):

  • Modify your silverface Fender amp to blackface specs
  • Convert the hum balance pot on your later silverface Fender into a real bias circuit (This is essential to make those amps sound great)
  • Install a bias pot or standby switch on your Princeton Reverb
  • Install a 12"speaker baffle in your Princeton
  • Remove the Bright Cap from your Deluxe Reverb
  • Bypass the vibrato circuit on your Fender to get more gain
  • Put a midrange control on your Deluxe or Princeton Reverb
  • Install a Master Volume in your Marshall - the Larmar post-phase inverter mater volume is recommended
  • Put an effects loop in your Marshall so you can use those delay and reverb effects while using amplifier distorion
  • Put a bigger Output Transformer in your  Princeton, Vibroverb or Pro Reverb - Bigger Tone!
  • Improve your tone by putting boutique transformers on your reissue amp
  • This list could be endless. If you have heard of a cool mod, ask me about it.

Amplifier Maintenance Services:

  • Tube replacement
  • Tube Biasing
  • Electrolytic filter capacitor replacement
  • Cleaning or replacement of potentiometers
  • Checking for out of spec or damaged resistors
  • Checking for capacitors leaking DC current
  • Cathode bypass capacitor replacement
  • Installation of new power cable with three prong plug to replace the dangerous two prong plugs and then removal of the "death" capacitor shock threat
  • Clean and re-tension tube sockets




Amplifier Repair:

  • Diagnosis and repair of any Tube Amp malfunction
  • Blowing fuses? - that's a sign you have a bigger problem, but most likely a shorted power tube
  • Replacement of any bad resistors, signal capacitors, electrolytic capacitors, tubes, diodes, transformers, jacks, switches, reverb tank or cables, etc



This old 1966 Fender Twin Reverb had been played alot over the years and was really suffering and we gave it a complete overhaul.  The reverb did not work so the reverb transformer was replaced. Replaced all Filter capacitors and electrolytic cathode bypass caps.  Replaced a boatload of out of spec resistors with NOS carbon comp resistors. Replaced the bias capacitor and resistor.  ALL of the ceramic capacitors were leaking DC voltage so they were replaced with silver micas or 716 orange drops.  Left the wonderful blue molded caps in the preamp, but replaced them in the phase inverter with 6PS Orange Drops as preventative maintenance (if they fail it will kill the output transformer).  The big screen grid resistors had drifted wildly out spec from years of heat and were replaced with NOS resistors.  The midrange control was changed from 10k to 25k to give even more raw tone in the mids.  All the tube sockets were cleaned and re-tensioned and the potentiometers were cleaned.  NOS preamp tubes installed and new production poweramp tubes installed and biased.  It's ready to go for another 50 years!

Texwest Guitar and Amplifier Service

This amp started out life as a 90's era 50 Watt plexi reissue Marshall 1987x.  The owner wanted it to be a boutique plexi recreation so we ripped out the stock printed circuit and replaced it with a point to point wired circuit board and loaded it with Sozo signal caps, a couple vintage mustard caps we had available, high end Vishay Dale resistors and a few NOS carbon comp resistors in the preamp.  We installed a boutique Obsolete Electronics Output transformer and Mercury Magnetics choke.  This thing was transformed into a screaming Rock n Roll machine.  It sounded especially cool when we installed a set of KT66 tubes instead of the usual EL34's.  The KT66's really made it sound like those early AC/DC recordings.  After all that, it definitely sounded better than the stock 1987x I happened to own at the time.