A “Greatest Hits” of Paul Rivera’s Amp Mods
Paul Rivera Sr.’s modded American amps have become the stuff of legend since they first burst onto the burgeoning ’70s LA pop scene. One need look no further than guitarist Paul Jackson Jr.’s work on Michael Jackson’s Thriller to appreciate the versatility of Paul Rivera’s designs. From a sugar-sweetened ultra-clean scratch to a snarling, fat, compressed crunch, this is one amp that truly goes the distance.
The Rivera Stage IV combo amplifier includes all the hallmarks of Paul’s famous American amp mods: a Master Volume for increased gain control; Fat, Bright, and Boost toggles for better tonal command; a Presence knob for accessing uncharted top-end American sweetness; and an upgraded tube and speaker complement to tap into the full magic of the late-’70s circuitry. On top of that, additional features include foot-controlled, fully independent channel switching and a buffered active effects loop with level controls for greater pedalboard integration. All told, the Stage IV represents the very best of Paul Rivera’s hand-modded American classics. At Sweetwater, we are confident that this amp is destined to become a gold standard — on any stage you take or session you step foot into. Quantities for these amps are extremely limited, so secure yours through Sweetwater now!
Related Videos: Stage IV 25-watt 1 x 12-inch Tube Combo Amplifier, Sweetwater Exclusive
The sound you know. The name you trust.
You’ve already heard Paul Rivera Sr.’s modded American amps on thousands of albums by such artists as Michael Jackson; George Benson; Cheap Trick; Ray Charles; Earth, Wind & Fire; Aretha Franklin; Art Garfunkel; Marvin Gaye; Hall & Oates; Engelbert Humperdinck; Al Jarreau; Manhattan Transfer; Barry Manilow; Johnny Mathis; Olivia Newton-John; Dolly Parton; Kenny Rogers; Diana Ross; Boz Scaggs; Steely Dan; Donna Summer; Barbra Streisand; and countless others. Now you can paint your own recordings using the same killer tone palette. From chimey chords and chunky rhythm parts to blistering single-note lead lines, Rivera’s Stage IV does it all.
“[The Stage IV] has a very unusual sound. The output transformer reacts to the inductance of the speaker in a peculiar way. There’s just a magic that occurs with the increased gain, fatter tone, and less ripple in the power supply.” — Paul Rivera Sr. on his Stage IV amp mods
Two Independent Footswitchable Channels
Channel 1: clean with loads of headroom
The Rivera Stage IV is a re-creation of Paul’s most celebrated modified combos. It starts with the Holy Grail of clean American guitar amps, a late-’70s American 1 x 12-inch tube pedal platform. Rivera’s first order of business was to transform it into a true 2-channel amp, with completely independent clean and lead channels, with their own Midrange and Reverb controls that can be toggled using the included 3-function footswitch. Headroom was then increased for less “flub” on Channel 2 — which can now function as your lead/overdrive channel. To spank up your tone, push-pull Bright switches have been added to both channels, as well as push-pull Notch switches that deploy American or British midrange control. In all, these controls give you endless variations on each channel.
Channel 2: overdrive and beyond
Channel 2 on the Rivera Stage IV combo is where things get hairy, in a good way. It starts with a 6-position rotary Fat switch that replaces the second input jack to thicken up the mids and increase harmonics. An important feature of the Stage IV’s channel 2 mods is the addition of a Master Volume with Boost toggle, which lets you dial in the overdrive for crunch at lower volumes or really crank it for searing lead work. Completing the front-panel mods is a Presence knob that adds shimmer to your sound. The Reverb knob operates in standard fashion to control the amount of classic spring reverb added to your guitar signal, while Tremolo controls have been rerouted to the back to make way for more common controls on the ampface.
6V6GT output tubes and tube recto
The Stage IV’s upgraded 6V6GT tubes can take more heat (voltage) than the original’s stock 6V6s while delivering a sound that’s closer to the late-’70s NOS originals. This gives you the best of both worlds: you can really cook your output tubes well into power amp distortion without sacrificing tube life. Paul’s Stage IV also features a specially chosen 5V4GA rectifier tube for vintage-era compression and squeeze.
DC preamp tube power supply
The Stage IV’s preamp tubes run off their own isolated DC power supply. This brings the noise floor way down. For cranked cleans, it’s almost inaudible. For cranked preamp crunch and lead tones, it’s way lower than you’ll find on a true vintage dimed original, even given the Stage IV’s increased gain capabilities.
Active effects loop
Let Sweetwater be the first to say that the Stage IV is one amp you can run straight into — guitar to amp — and find inspiration. But if you’re a pedal lover, you’re definitely going to appreciate Paul’s added active buffered effects loop. Send and Return levels let you calibrate your reverb, delay, and chorus pedals for maximum response.
Rivera visual enhancements
A special “Rivera Modified” grille logo and telltale blue power jewel give the Stage IV that irresistible Rivera mod appeal. Put Paul Sr.’s iconic amp mods to work for your next appearance. From the stage to the studio, the Rivera Stage IV from Sweetwater is a home run for modded American clean amp tones.
Rivera Amplification Stage IV Features:
- 25W 1 x 12-in. combo amplifier based on Paul Rivera’s Stage IV amp modifications
- True 2-channel operation, selectable via included footswitch
- 12-in. Eminence EM12 speaker
- 6V6GT output tubes are voiced like NOS and are rated to withstand higher voltages
- Tube rectifier supplies golden-era amp compression
- Channel 1 (clean): Volume, Treble (Pull Bright), Middle (Pull Notch), Bass
- Channel 2 (higher gain): Volume, Treble (Pull Bright), Middle (Pull Notch), 6-position Fat selector, Bass, Master Volume (Pull Boost), Reverb, Presence
- Channel 2 can operate as a lead/overdrive channel
- Increased headroom for less “flub” on channel 2
- Bright switches spank up your tone
- Notch switches toggle between British and American frequencies
- Boost switch intensifies lead work
- Channel 2’s 6-position rotary Fat switch thickens up mids and increases harmonics
- Master Volume control lets you dial in preamp overdrive for crunch at lower volumes
- Presence control adds uncharted shimmer to your tone
- Classic tube spring reverb and optical tremolo (trem controls around back)
