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We also stock George L's cables, Mojotone Extension Cabinets, amps and effects on consignment, and more.  Stop by the shop and see what we have!

Guitar Amp Modifications and Tweaking

Check out our new Hot Rod Deville mods and Hot Rod Deluxe mods.
 

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Fender Tube Amp Modifications

Also see the section below about general mods for most amps.

Modifications for Princeton Reverb (blackface and silverface)

• Increase intensity of tremolo effect - **$15
   

Blues Jr. Modifications

• Correct the bias circuit so that the output tubes no longer overheat.  Overheating tubes can cause damage to the tube sockets, circuit board and premature failure of the tubes.  This is normally done when output tubes are replaced.
   

• Correct factory problem with wiring that causes ultrasonic oscillation, bad tone and premature tube failure.  (This is not a problem on every Blues Jr.  We can scope the output to see if your amps is in need of this mod.)  **$20
   

• Replace plastic output tube sockets with more durable ceramic type.  **$30
   

• Install and 2 position power switch so you can have a standby function.  **$35 (while supplies last). Temporarily out of stock.

• We can also install your Bill M mods.  Either you can purchase the kits from www.Billmaudio.com or we can supply the parts for the "Basic Mod" and several others from our inventory.   Some mods such as the "clean boost module" and transformer upgrades must be purchased from Bill.
   

Modifications for Blues Deluxe, Blues DeVille, Hot Rod Deluxe and Hot Rod Deville

• We've developed our own modifications for the Hot Rod amps that will improve the tone and controllability of the amp.   Here is what you can expect...
  1)  The clean channel will have a more classic-type tone with a little less gain (on both channels).  The bass will be slightly reduced bass frequencies will be a bit tighter overall.  The treble frequencies will be a bit smoother.  The clean channel volume control will not so touchy in the low numbers.
  2)  When playing the dirty channel, the Master volume control will be more evenly adjustable instead of being so touchy in the low numbers.
  3)  Ghost notes that are normally heard when playing single-note leads at high volume will be greatly reduced and the low strings will sound a bit tighter (less flabby). 
  4)  The treble boost of the Bright switch will be less extreme.

Cost - $135 for Hot Rod Deluxe and $145 for Hot Rod Deville.
***  NOTE - a substantial portion of the price of these mods is the disassembly of the amp, removal and re-installation of the main PC board.  If your board is being removed for other work, the price of these mods will be lower by about $65.

• Triode/Pentode Switch (1/2 power switch)- This allows to you reduce your output power level to about 1/2 of normal.  This usually means a reduction of around 20% in output volume. There is also a slight reduction in treble.  $80
   

• Install metal Switchcraft input jacks.  These are much more rugged than the plastic ones installed in the American-made Deluxes and Devilles   Cost is $90.  If we already have the board out for other repairs or mods, we and upgrade the jacks for $30.  The Mexican versions of these amps have upgraded plastic jacks that don't typically break.
   

• There are also several Fender factory reliability mods for the early versions of these amps.  We can do these as well.  We'll have to look at your amp to see if these have already been done.
   

• The 4 X 10 version of the Deville had under-rated speakers from the factory and we've seen many bad ones.  For a bright crisp vintage style tone at a good price, consider having us install a set of Jensen C10Q speakers.  See our Jensen C Series Speakers Page for the latest prices and discounts.  For a deeper, warmer, and louder tone, try the Eminence Ragin Cajun speakers.  The Ragin Cajuns mate especially well the the bass reduction mod above.  They're rated at 75 watts each and carry a 7 year warranty so you won't have to worry about trashing them no matter how loud you play.
   

Modifications for Deluxe Reverb

• Remove the treble boosting capacitor on the reverb channel for a warmer tone.  This is a popular mod on the re-issues but rarely needed on the vintage ones.  **$10
   

• Install a solid state rectifier and 6L6 output tubes.  This will give you a bit more clean headroom and volume.  We have to make sure your power supply capacitors are in good shape before doing this mod.  In fact, I recommend adding changing some of the filter caps to higher values for this mod.  Price varies depending on the tubes you choose.

Modifications for Twin Reverb

• Ever wish the Twin Reverb was a bit lighter and wasn't quite so loud?
  Bring in a Blackface or Silverface Fender Twin Reverb and let us convert it to a 20/40 watt 2X12 "Super Deluxe Reverb".  Your Twin will shed a few pounds in the process too!  Price:  $595     This includes the following:
       Replace both transformers.
       Install 4 new 6V6 output tubes.
       Install octal tube socket for tube rectifier.
       New GZ34 Rectifier tube.
       Re-locate and mount transformers, choke and bias pot
       All new power supply and bias supply capacitors
       Several  minor circuit changes to accommodate the different power levels
       Half power switch so you can switch between 20 watts and 40 watts of output power

Modifications for most silverface models

• Convert circuit to Blackface specification.  Click here for more info. Fender Blackfacing

• Convert to a better bias adjustment circuit for improved tone and longer power tube life for your silverface Fender amp?  This is included in the "blackfacing" conversion or can be done to many other amps as a separate mod.

• Modify to get rid of that "ticking" sound in your vintage Fender vibrato circuit?  **$15
   

Modifications for most models with reverb and tremolo

• Wire for reverb and tremolo on both channels - **$25

Modifications for most models without reverb

• We can add spring reverb to your Fender Deluxe, Bandmaster, Concert or Showman.  You'll have to give up the vibrato function and the "Normal" channel that you probably never use anyway.  The new reverb circuit will feature dwell, bass and treble controls.  Cost is around $225 to $275 depending on whether you want it to be footswitchable or not.  Note: there is not enough room in the head cabinets to add the tank without excess humming so if you want this added to a head model you'll have to find a bigger cabinet or mount the tank outboard of the head cabinet.  There is no problem adding the tank in combo models.  Not available for Champs, Broncos and Princetons.
   

Modifications for all Blackface amps

• Install a grounded AC cord and correct the out of date AC wiring so that the amp will be safer and much less likely to cause nasty electrical shocks.  **$25

 

Marshall Tube Amp Modifications

• Do you find the Crunch and Lead channels in your Marshall JCM2000 to be too bright and piercing?  We can tame the treble without affecting the clean channel.  Cost is $55 to mod one channel and $75 for two channels.
   

• Treble taming mods are available for many other Marshall models as well.
   

• Convert from 6550 or 5881 to EL34 output tubes.  (or visa versa).
   

• Mercury Magnetics Transformer upgrade and/or the addition of a choke.  This mainly applies to newer models.
   

• Also see below.

 

General Modifications for Most Tube Amps