Amp Mods

                                                                 "Serious Tone for the Serious Musician"

Griblinengineering.com
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We’ve created quite a reputation for our ability to pull new tones and options out of old amps. Specializing in pre-80’s Fenders and traditional Marshalls, we can build the amp of your dreams. We can turn your mediocre Silverface into a vintage sounding Blackface or your Fender into a Marshall or Vox. We can give you killer, smokey, blues tones and screaming rock sounds and anything in between, plus add options like FX loops, channel switching, mid boosts, overdrives, master volumes, mixer controls to let you blend between preamps, add reverb to non-reverb amps, and more. Here is a listing of some of our more popular mods, but keep in mind that we do a lot more than what is listed.

Also being offered to the general public for the first time is the "Professional Version" of our mods. This upgrade is usually reserved for our professional musician clients who are steadily recording, touring and gigging and need every ounce of tone squeezed out of their amps and need the amps to be as reliable as possible. We accomplish this by completely "blueprinting" key parts of the circuit. We test parts and match them before they ever get installed in your amp, something that no production amp has done to it. By doing this we get increased performance, better harmonics, and, bottom line, better tone. Additionally we take preventative measures by beefing up certain components and installing additional circuits to prevent problems caused by power surges or voltage spikes. This improvement is done without any loss of tone. So should you get the Standard or Professional version on your amp mod? Basically the Standard version will blow away any amps that are on the current market. Simply put they sound killer. Stepping up to the Professional version means that you want to take your performance and tone up another notch and want to keep the thing running for as long as possible. Both are great so do whatever is within your budget.

If you decide you want to send us an amp to modify, be sure and visit the Contact Us page which contains shipping instructions to insure that your amp gets here safely.

Texas Special

Without a doubt the most common requested tone has to be the "Texas Tone".  With the influence and intensity of Stevie Ray Vaughan's playing, it's hard not to appreciate the amazing sounds he was able to get out of his amplifiers.  He would mix and match a number of amps and combine elements of each one to get one huge, "perfect" tone.  Unfortunately, this is not possible for most of us to do, nor do most of us want to carry around ten different amps to get one or two good sounds. 

We've found a way to get real close - with only one amp, and it could be one of the most versatile amps you will ever come across.  This is our most requested amp mod and will give you two independent channels, each with their own set of tone controls.  The clean channel is incredible, somewhat like on Stevie Ray's "Lenny".  Very bluesy and full sounding with just enough breakup to give it that human-like quality.  This channel practically breathes.  Add a touch of reverb and you can get lost in the mood if this channel - it's that good.  Step on the pedal and you switch into overdrive.  More power, more crunch, more sustain.  Better sounding than an effects pedal because it's an actual tube overdrive.  You get that warm, compressed, natural sustain for stinging leads or crunchy power chords.  You can turn the gain low for smokin' blues tone or crank the gain up and cross the tracks into scorchin' rock territory.  If you could only have one amp, this would be it.

Additional features:  Active buffered effects loop for increased performance from your effects, channel switching complete with foot pedal, midrange boost, and lead master.

Standard Modification..................................................$395.00

Professional Version....................................................$495.00

Blackface Boogie

A beautiful, vintage Blackface clean channel and a hot, fat, crunchy overdrive that rivals a Boogie for sustain, but beats it hands down on overall tone.  Rockers and modern blues players love this one because of the expressive nature and gobs of sustain from an amp like this. 

Additional features:  Active buffered effects loop for increased performance from your effects, channel switching complete with foot pedal, midrange boost, and lead master.

Standard Modification..................................................$395.00

Professional Version....................................................$495.00

Blackface Conversion

Transform your Silverface into the classic, sought after tone of the Blackface amps.  Warm, full-bodied with that nice break up when you push it.  We even upgrade the preamp caps for you.

Standard Modification...................................................$99.00

Professional Version....................................................$199.00

Tweed Conversion

To many the original Tweed model Fenders of the 50's set the standard for guitar amp tone.  In fact the 4 x 10 Tweed Bassman circuit was what Marshall used as the springboard for their amps.  We can build this circuit into your amp and give you that sweet, fat, warm tone that tone freaks love.  Additionally you get an additional gain stage which you can plug into to get that extra overdrive and sustain when you want to rock.

Standard Modification..................................................$295.00

Professional Version....................................................$395.00

Channel Switching....................................................add $99.00

Effects Loop...........................................................add $125.00

Top Boost Plexi

Originally designed for Bassman heads, but can be adapted to other Fenders for an additional charge.  Basically we build one channel with a Vox AC 30 Top Boost circuit and the other as a dialed in Plexi Marshall circuit.  Gain boost circuit is great for dirty rhythms or bluesy leads.  And the best part is that the channel switching allows you to go from Top Boost to Plexi or both simultaneously for an amazing, unique sound unlike anything else.

Standard Modification..................................................$395.00

Professional Version....................................................$495.00

Effects Loop...........................................................add $125.00

Killer Marshall

Play enough Marshalls and you'll find out that they are extremely inconsistent.  You bought the amp to get that great tone you heard on the recording, but when you got home you found out you weren't even close.  Truth of the matter is that most of those great Marshall sounds you've heard are actually great modded Marshall sounds.  Our Killer Marshall mod first tweaks the basic preamp to get it to perform the way it should have off of the assembly line, and then we build an extra gain stage to push the performance level up 10 notches to get that classic Marshall crunch and sustain.  When things are dialed in right, they are a lot of fun to play.  Intended for standard Marshall models, like JMP's, JCM 800's, Super Leads, Plexi reissues, etc.

Standard Modification..................................................$295.00

Professional Version....................................................$395.00

Channel Switching....................................................add $99.00

Effects Loop...........................................................add $125.00

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