Hands-On Review: Ampeg SVT-4 PRO Bass Head

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Wall-shaking power and total tone tweakability!

By Justin Maertens

For as long as I can remember—and that is a long time indeed—the name Ampeg has been synonymous with excellence in bass amplification. Like the bassist in what was then the hot new band The Rolling Stones, the bass player in my first band played an Ampeg (albeit not one of the 300-watt monster SVTs the Stones used)! These days, Ampeg continues their tradition of excellence. Artists as diverse as Michael Anthony of Van Halen and Tony Levin of King Crimson rely on that Ampeg sound day after day in the studio, and night after night on the road. Although I play guitar, I like to keep the best equipment possible in my studio for visiting musicians, and for when I want to lay in parts myself. After my bassist raved on about his SVT-4 PRO, I talked him into letting me borrow it for a few days to put it to the test.

Class of the head

The SVT-4 PRO has some pretty amazing specs. It offers all the power and punch you could ever desire in a bass head, packing 1,200 watts of combined tube and solid state wallop into just three rackspaces!

The build quality is very good too—the construction is super-solid, unlike some lesser heads. The knobs have a great grip and a firm feel, and like a good handshake, help get things off to a great start. Also in the first impressions department are looks, and the looks of the SVT-4 PRO are outstanding! The sculpted black face is elegant and powerful, and the clean, intelligent design makes it easy to work with as well. Sturdy grips protect the face from accidental damage and make it easy to haul this 42-pound monster around.

Inside, hybrid technology gives you the best of both worlds. A tube preamp stage delivers that smooth creamy tone we all love, while the MOSFET-based power section churns out solid, reliable amplification without unnecessary delay or maintenance woes.

The front panel features an input as well as a tuner output—a welcome addition. Next to the tuner output is a mute switch, which mutes everything but the tuner out—very handy! Also by the input section is a 15dB pad to accommodate active pickups. A peak LED complements the Gain control, so you know if you’re pushing the limits; and the Compressor section lets you smooth out the sound and add sustain. Two switches, Ultra High and Ultra Low, boost their respective frequency ranges for extra clarity and kick. The Bass, sweepable Midrange, and Treble controls follow, and a Bright switch kicks in even more high-end response. The Grapic EQ switch activates the nine-band equalizer, which can also be activated via footswitch (really handy if you want to use the EQ settings to kick it up a notch for solos). The Line Out level is ideal when you are recording direct, and the SVT-4 PRO offers four line out jacks on the back! The Crossover Frequency and Balance controls come into play when you are using the SVT-4 PRO in biamp mode, and the Master volume control puts it out there for all the world to hear!

Ampeg SVT-4 PRO Series Bass Head
Ampeg SVT-4 PRO Series Bass Head

The back panel features the usual complement of output jacks, including Neutrik Speakon connectors (and 1/4" speaker jacks, should you need those), and adds such niceties as a stereo effects loop, transformer-balanced line outputs with both XLR and TRS connectors, biamp outputs, and a preamp output section so you can use the SVT-4 PRO with other amps should you so desire.

Ampeg SVT-4 PRO Series Bass Head Back Panel

You get the picture—this amp is loaded to the gills with features and benefits. But in the real world, the final question is always “how does it sound?”

Bottoms up

The first order of business before making noise was to connect it to the cab, in this case the Ampeg SVT-410HLF (because I love to feel the bass, not just hear it). The aforementioned Speakon connectors were a welcome sight—nothing worse than lightweight plugs on a system this beefy! Now well connected, I powered up and plugged in my Fender J Bass. The first word out of my mouth when I was done with my first riff was WOW! I’ve got some decent gear in my studio, but what I heard was amazing, three-dimensional audio—big, thick, punchy gobs of bass sound filled the studio with lows enough to shake your gut, but still clean and clear enough to engage your ears! Things really got interesting when my buddy brought over his custom-built six-string bass. Now to be honest, I just plunk away and pretend to be a bass player, but he really plays that thing—and when he laid down a funk riff that slammed home on the open low B, I just about fell out of my chair! We played funk. We played blues. We pushed jazz, rock, and metal through the SVT-4 PRO, and with the flexibility and raw power this amp offers, it all came through sounding superb!

Bottom line

If you’re looking for a powerful, all-around excellent performing bass amp with nearly infinite tonal flexibility, the Ampeg SVT-4 PRO should be on your must-have list. I was so impressed with it, I returned my loaner and made the call— and my very own SVT-4 PRO is on its way as I write this!

Features & Specs

  • 1200 watts @ 4 ohms (2 x 600W)
  • 3 x 12AX7 preamp tubes
  • MOSFET power amp
  • 3-band EQ
  • 9-band graphic EQ
  • 5-position mid tone control
  • Ultra Low and Ultra High boost switches
  • 1/4" biamp high and low outputs
  • Neutrik Speakon outputs
  • 2 effects loops
  • Dual 1/4" inputs
  • Input peak LED
  • -15dB pad for active basses
  • Variable 0-7:1 Compressor
  • Bright switch
  • Defeatable optocoupler limiters
  • Internal 24dB/octave crossover
  • Linkwitz-Riley state variable filters
  • 50Hz-1kHz variable crossover point
  • High/Low balance control
  • Tuner out jack
  • Mute function
  • 19"W x 5-1/4"H x 15-1/2"D
  • 42 lbs.

Tags: Amplifiers


# Dave o 2015-06-17 15:25
Where is the direct out on the SVt 4 pro
# Marlena 2014-04-27 14:20
what class amp is the SVT 4 pro?

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