Sound City L/B 120 Mark IV

Sound City L/B 120 Mark IV
Amp courtesy of Uri Garcia, photos by Andrew Seward.
Preamp tubes: three ECC83 (12AX7), one ECC81 (12AT7, in the phase inverter)
Output tubes: six EL34
Rectifier: solidstate
Controls: Normal Volume, Brilliant Volume, Bass, Middle, Treble, Presence
Output: approximately 120 watts RMS

If you spent time in the ’90s kicking around London rehearsal studios or gigging at any of the dozens of venues, you were familiar with Sound City amplifiers.

Somewhat similar to the less-often-procured Hiwatt amps, and perceived to be down a peg from those or the Marshall and Vox amps that also proliferated the scene, ’70s Sound City heads were a dime a dozen – not for those who aspired to a serious amp. They littered the corners of second-hand gear exchanges and railway-arch practice facilities.

Did they sound as dreary and pedestrian as their omnipresence implied? Well, if you kept the Volume knob at nine o’clock or below and used them mainly as a pedal platform, as the music (and venues) of the era often demanded, yeah, they generally did. But, crank one up through a stout 4×12″ cab or two and use it to “rawk” ’70s style as its maker intended, and you opened up a whole new world of big-boned tube tone, and in the process maybe jolting a few new cracks in the club’s foundation.

Sound City amps were born cheap relative to other major British brands, but that doesn’t mean they were born bad. Affordability was their raison d’etre, but they were conceived out of serious aspirations.

Sound City L/B 120 Mark IVSomewhat like Orange and Marshall, they were born out of the London music store that gave them their name, located in Rupert Street in swinging Soho. One of several owned by Arbiter Electronics (itself a subsidiary of Dallas Musical, Ltd.) by the mid ’60s, it was part of a concerted effort to poke a finger into every corner of the rock pie. In 1966-’67, Sound City amps emerged as one aspect of Dallas-Arbiter’s drive to corner the British music-gear market by supplying budget-priced yet extremely functional and good-sounding equipment. Early classics to have come from the venture included the Dallas Rangemaster Treble Booster and the Dallas-Arbiter Fuzz Face, but Sound City products faced a somewhat better-developed competition by the time they emerged.

It would be easy to assume, in hindsight, that Sound City amps were “copies” of Hiwatt models, since early versions very closely resembled them, inside and out. The fact is, though, that Sound City amps hit the streets before Hiwatt, the similarity down to the simple fact that many were designed by legendary Hiwatt founder Dave Reeves, an Arbiter employee of the mid/late ’60s who took his designs with him when he went independent in ’68. They also continued to use the same cabinet manufacturer. Another noted British amp designer, Dennis Cornell (still a respected “boutique” maker today) worked under Reeves, and designed Sound City models after Reeves’ departure. With all this in mind, it makes sense that Pete Townshend played Reeves-modified Sound City heads in 1967-’68, before moving on to Hiwatt-branded heads that were largely filled with Sound City guts. The consummate craftsman, a man self-charged with the task of building the most reliable guitar amp that could be built, Reeves formed Hiwatt to build a better mousetrap; Sound City amps sounded great and did their job well, but the business model put a ceiling on the quality of the components and workmanship that could go into them. In other words, they were “corporate” amps, manufactured with eyes firmly on the bottom line – but designed by a couple of true masters. That said, this was “affordability,” early-’70s style; Sound City amps used great Partridge transformers and many other standard-grade components that were entirely decent, especially compared to what you’d find inside a mass-market amp circa 2015.

The 1974 L/B 120 Mark IV featured here comes from an evolved Sound City lineup, and is one of the notable designs to have moved on from the brand’s Hiwatt roots. Its knobs offer the standard functions on Marshall and Hiwatt amps, if in jumbled order, but they control something very different going on inside. Standard and Attenuated inputs for the Normal and Brilliant channels feed those respective Volume controls, after which the signals are junctioned into the Bass, Middle, and Treble controls. Unlike the EQ stages of most amps, however (even those with some element of tube drive such as the classic Marshall cathode-follower tone stack), each knob in this lineup is entirely active. Turn up Bass, Middle, or Treble respectively, and you add gain precisely to that portion of the frequency spectrum, courtesy of an individual ECC83 (aka 12AX7) triode attached to each stage in the circuit. Turn them all down, even with each channel’s Volume control fully up, and you get nothing. This configuration makes for an amp that takes a little getting used to alongside the standard passive-interactive tone stage, but one that makes a powerful sound sculptor once you get the hang of it. Presence governs high-end content at the output stage, and the amp’s full wallop of 120 watts (and even more when it was really roaring) comes courtesy of six EL34s in a fixed-bias output stage. Examples made just previous also included an attenuated headphone output on the front panel, as well as Reverb In/Out jacks on the back panel (an effects loop, essentially), all of which have been plugged on this chassis, though their legends remain.

“This amp is special because it is super touch-sensitive,” says Uri Garcia, who provided this Sound City 120 for our edification. “When I was playing it twice a week, I would have all the dials set to maximum, except for setting Presence to taste for the room. I could have the amp all the way up and strum delicate chords or pick single notes lightly and it was loud and super clean. When I dug into the guitar hard and played something heavy it sounded like a chainsaw. There’s nothing like this amp into eight 12″ speakers. It’s the ultimate ’70s rock amp, with just that right amount of extra-funky vibe.”

Indeed, it’s a firebreather that offers a ready taste of what tone was like when you were not only able, but expected to crank it up.

Sound City L/B 120 Mark IV
For the sake of function, this amp’s original “mustard” caps were replaced with modern SoZos, and most of its electrolytic capacitors have been “renewed.”


This article originally appeared in VG‘s April 2015 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.