Optimal voltage for a superior tone!
If you want to get the most out of your tube amp, you need a BrownBox!
Tube amps are designed to run at an optimal voltage, and standard 120V/AC wall current is typically too high for them.
The BrownBox lets you bring the current down to an optimal level, resulting in significantly improved amp performance.
Another benefit of running your amp at the optimal voltage is that your tubes will usually last much longer.
Whatever the venue, you’re sure to supply your amp with the optimal input voltage for your personal sound!
AmpRX BrownBox Voltage Attenuator features:
• The perfect way to optimize the input voltage for your tube amp.
• Dramatically improves your amp's performance!
• Optimal input voltage extends the life of your power tubes.
• LCD voltmeter makes it easy to dial in the optimal setting for your amp.
• Selectable input current setting ensures safe and accurate operation.
• Choose from 4 attenuation modes to fine-tune your voltage.
• Bypass mode lets you easily A/B the results of your optimized amp voltage.
• Braced metal chassis and protective bar withstand the most brutal touring conditions.
Specs
| Type | Attenuator |
| Condition | New |
| Power Handling | Up to 540W |
| Manufacturer Warranty | Lifetime |
| Country of Origin | United States |
FREE SHIPPING
- Free shipping within Canada.
- Free shipping to the USA.
- Free shipping on international orders over 520$.
Visit the Shipping page for more.
Fast Delivery
- Canada : 1 - 2 business days
- USA : 1 - 2 business days
- Rest of the world: 3 - 5 business days.
Hassle-Free Returns
You have 45 days to test your new gear. If you choose to return it, we’ll send a full refund. It’s that simple: no bogus restocking fees or charges.
Visit the Returns page for more.
Frequently Asked Questions
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How can I tell if an item is in stock? +
Each product page shows an availability status.
• In stock items are ready to ship.
• Out of stock items are currently unavailable.
You can enter your email to be notified when an item is back in stock.
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Where are you located? +
We’re based in Blainville, Quebec, Canada.
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When will my order ship? +
Orders placed before 12 PM EST ship the same business day.
Tracking details are sent shortly after purchase.
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How much does shipping cost? +
Most orders ship free to Canada and the US.
International orders ship free on purchases over $520 CAD.
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Which shipping methods do you use? +
Orders ship via UPS Expedited by default.
For faster delivery, you can select UPS Express Saver at checkout.
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How long does shipping take? +
Typical delivery times are:
• Canada: 2–3 business days with UPS Expedited, 1 business day with UPS Express Saver
• USA: 2–3 business days with UPS Expedited, 1 business day with UPS Express Saver
• International: 3–5 business days with UPS Expedited, 2–3 business days with UPS Express Saver
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Which payment methods do you accept? +
We accept all major credit cards and PayPal.
Financing options are available through Klarna and RBC PayPlan.
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Do Canadian customers pay sales tax? +
Yes. Sales tax is applied based on your province of residence:
• Alberta: 5%
• British Columbia: 5%
• Manitoba: 5%
• New Brunswick: 15%
• Newfoundland and Labrador: 15%
• Northwest Territories: 5%
• Nova Scotia: 14%
• Nunavut: 5%
• Ontario: 13%
• Prince Edward Island: 15%
• Quebec: 14.975%
• Saskatchewan: 5%
• Yukon: 5%
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Do USA customers pay import fees? +
Yes. Starting August 29, 2025, all US-bound shipments will be subject to duties, taxes, and brokerage fees.
These charges are determined by US Customs and collected by UPS at delivery.
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Do international customers pay import fees? +
Yes. International shipments may be subject to duties and taxes.
These charges are set by the destination country’s customs authority and collected by UPS at delivery.
Customer Reviews
Using the Brownbox with a pair of fender deluxe custom 57 tweed amps really adds a great smoothness to the mids. I’m running at 114Volts. Feel wise it provides an even better connection between strings and fingers.A great experience buying online with Electric Mojo Guitars. Thanks Charles!
It’s not my first time buying great gear from Electric Mojo Guitars and won’t be my last. They never disappoint and shipping is always very quick for me here in NB Canada. Totally loving my new Amp RX BrownBox for my 74 Marshall 2203!
Glen
Works great at protecting your amp by reducing the input power
Well built, easy to use and very useful for dialing down line voltages. Would recommend to anyone with vintage or boutique tube amps
It works great