AmpRX BrownBox Guitar Amp Power Correction/Voltage Optimization Unit


0% Interest for 6 Months**

On Purchases of $199 or more with your Sam Ash credit card. Interest will be charged to your account from the purchase date if the promotional purchase is not paid in full within 6 months. Minimum Monthly Payments Required.

Read more

0% Interest for 6 Months

On select purchases $199 or more with your Sam Ash card now thru 06/25/21.

On Purchases of $199 or more with your Sam Ash credit card.* Interest will be charged to your account from the purchase date if the promotional purchase is not paid in full within 6 months. Minimum Monthly Payments Required. Note: Your first order with your Sam Ash Credit Card can only be shipped to the billing address on your application.


*Offer applies only to single-receipt qualifying purchases. No interest will be charged on the promo purchase if you pay the promo purchase amount in full within 6 months. If you do not, interest will be charged on the promo purchase from the purchase date. Depending on purchase amount, promotion length and payment allocation, the required minimum monthly payments may or may not pay off purchase by end of promotional period. Regular account terms apply to non-promotional purchases and, after promotion ends, to promotional balance. For new accounts: Purchase APR is 29.99%; Minimum Interest Charge is $2. Existing cardholders should see their credit card agreement for their applicable terms. Subject to credit approval. We reserve the right to discontinue or alter the terms of this offer at any time.


Qualifying items must be purchased at the advertised tagged prices. This offer is not valid for price matches, competitor coupon matches, used or previously marked down items, closeout gear or door busters.

Seen a better price?
For superior tube amp performance, consistent signature tone and professional control over your sound, look no further than the AmpRx BrownBox Guitar Amp Power Correction/Voltage Optimization Unit.
In Stock & Ready To Ship!
Whether you're recording or performing, the BrownBox is the ultimate solution for professional guitarists who want the very best sound out of their tube amp. Used by some of the biggest names in rock including Joe Walsh, Joe Hottinger (Halestorm), Brad Whitford (Aerosmith), and plenty more, the BrownBox will make your vintage tube amp sound the way that it was always meant to.

The BrownBox is a voltage optimizer that was designed to offer a safe range of voltage reduction levels made specifically for the same, era-correct voltages that vintage tube amps were designed around. The result is the pure authentic tube tone, classic tube saturation, and all the rich harmonic content that you want from your vintage tube amp.

The Brown box is a bit of an enigma to some first time users of the product, because there has never been a device exactly like it offered ever before.

So…what does it do?

Let's start with what is not.
1. A stomp box
2. An attenuator in the commonly used way

The Brown box enables your amp to work as it was designed. This is especially true for vintage and vintage-inspired boutique amps. Many discerning guitarists seek to recreate a favorite player's tone, and scrutinize their signal path, right down to the cables that connect stomp boxes. Many players use old-school carbon dollar store 9-volt batteries in their vintage treble boosters and fuzz boxes to achieve an authentic sound. It seems that alkaline batteries are more efficient, and supply too much power to the effect. The BrownBox is no different. It lowers the line voltage from your wall to what the designers intended. The change in sound goes from slight to significant, depending on what you are using. An important side effect of the lower or "browned out" voltage is longer life for tubes, caps and all internal components. The BrownBox cleverly meters the line voltage from the wall, and then can be selectively lowered to the desired amount. Now you can hear what a '59 Bassman sounds like with 1959 power, in a nutshell. The result is hearing your amp as designed, for the first time. Imagine a 112 volt amp being powered with 112 volts, instead of drawing the 120,122, or higher line voltage coming out of a modern wall socket. As guitarists, we scrutinize rigs down to the right kind of pick. The true starting point of your tone happens before you even plug in. See and hear what you have been missing!

One BrownBox will handle any combo amp, and up to a 100W head. Not intended for solid state amps.

Benefits of Voltage Optimization:

  • Establishes the basis for  your signal chain and the starting point in building a consistent signature tone. Earlier power tube saturation equals earlier break-up at more usable volume levels.
  • A smoother tonal shift  toward even order harmonics, revealing  the amplifier's true designed tone fundamental.
  • Lower internal voltages = lower dissipation = longer component life.

BrownBox Features:

  • Easy to read, back-lit L.C.D. display enabling real-time voltage and amperage monitoring, also useful for diagnostics.
  • Tough road rugged construction.
  • Proprietary Transformer designs wound exclusively for use with tube amplifiers, an industry first!
  • Filament soft-start in full reduction mode.
  • A powder coated EMF neutral housing. In-rush current protection, fused over-load protection .
  • Silent, cool operation.
  • Custom wound 5 amp proprietary transformer that will supply 540 watts max@ 120 Vac. Designed for Mid to larger sized Amps, Fender Bassman, Marshall 50s/100S Etc or for Parallel or ( DUAL) amp rigs. Be sure to Check the Manufactures info plate on the rear of the Chassis for input watt requirements.
  • Made in the USA.

Get your AmpRx BrownBox Guitar Amp Power Correction/Voltage Optimization Unit today at the guaranteed lowest price from Sam Ash Direct with our 45-day return and 60-day price protection policy.

Things You Will Get:

  • Voltage Optimization Unit
  • Model Number BROWN BOX