“Declared the ‘best-sounding tweed Fender’ by many players.” We review the Cutthroat Audio Fullerton 5G9 1x12, a modern re-creation of a storied Fender combo

Long a sleeper in Fender’s original tweed amplifier lineup of the 1950s, the 5G9 Tremolux didn’t officially exist until a handful of players, collectors, and vintage-amp aficionados finally put the pieces together. No one, to my knowledge, has ever reported seeing this model of the 1x12 Tremolux combo from 1959–’60 with a “5G9” tube chart, although a schematic for the model exists. Perusing that diagram reveals that this circuit has quite a few significant differences from the 5E9-A Tremolux that preceded it.

And I should know, having owned two great original 5G9s in the past, both of which had 5E9-A tube charts pasted inside their finger-jointed solid-pine cabinets.

Its elusive nature aside, the 5G9 Tremolux was discovered in a big way several years ago, having been declared the “best-sounding tweed Fender” by many players (although that’s a subject guaranteed to drum up some debate).

So with prices for originals soaring, Ron Westwood of Cutthroat Audio decided to put his own passion for this late-era tweed wonder to work by creating the Fullerton 5G9 Tremolux combo.

For several years before segueing into hand-wired amp manufacturing, Cutthroat Audio specialized in high-end instrument, speaker and patch cables, and Westwood has taken a similar obsession with the minutiae of tone-enhancing components into this homage to the 5G9.

The Fullerton closely replicates all the essentials of the design while adding some conveniences for the contemporary player that nevertheless shouldn’t detract from the overall vintage vibe and performance. It’s all wrapped into a classic 18-watt, dual-6V6 combo that’s housed, in this case, in the option of a lightly aged lacquered tweed cabinet.

In addition to its stealth nature, the 5G9 Tremolux was something of an anomaly in Fender’s amp lineup, and one we can refer to variously as “the biggest small Fender tweed amp” or “the smallest big Fender tweed amp,” depending on how you slice it. The original iteration of 1955, the 5E9 Tremolux, was Fender’s first amp to carry tremolo and wasn’t far off from being a 5E3 Deluxe with the effect built in. In a few years, however, that would change dramatically.

The amp earned a larger cabinet first, moving into the same one used by the dual-6L6 Pro Amp. Next, the circuit was heavily updated to include many features seen in Fender’s larger amps.

While the 5G9 still has the simple dual-volume preamp with shared tone control of the tweed Deluxe, that was coupled to the same long-tailed-pair phase inverter and fixed-bias output stage used by the legendary 5F6-A Bassman, making the Tremolux Fender’s only 6V6-equipped amp of the ’50s to carry these features. It also used a stouter 5U4GB rectifier tube than the Deluxe’s relatively soft 5Y3.

And while the change of phase-inverter circuit robbed the 5G9 of the 5E3’s extra gain stage, the deletion gave the Tremolux a lot more clean headroom, which couples with the higher voltages to enable a tight low end and plenty of clean punching power.

In addition to adopting these traits, Cutthroat has added several of the clever twists seen in its Down Brownie and Francene combos previously reviewed in GP. While it includes the lower-gain 12AY7 in the Bright channel — a preamp tube that was original equipment in the vintage Tremolux — there’s also a higher-gain 12AX7 that can be swapped into the circuit via a push-pull switch on that channel’s volume control.

The generally redundant Normal channel has been revoiced with a Marshall JMP50 Lead spec–inspired circuit, and the otherwise unused half of the 12AY7 in V1 is tapped to add the extra gain stage the original 5G9 is otherwise missing, accessed via a push-pull on the tone control when you need extra grind. The popular tweak of jumpering the two channels together with a short cable is made easier thanks to a third push-pull on the Normal channel’s volume pot that internally couples Bright and Normal.

The amp’s namesake tremolo effect is of the bias-modulating variety, which acts on the output tubes’ bias point and is known for its lush, warm throb, given a slight revamp here to enable even slower speeds.

Cutthroat has added further modifications in the form of a post-phase-inverter master volume control (housed in the hole where the standby switch would go, with standby mode achieved via a three-way power switch); a three-position negative-feedback-loop switch that offers standard, less, and none, for three further degrees of gain; and a tube/solid-state rectifier switch.

Finally, there’s a switch to select four-, eight- or 16-ohm speaker output. Unlike the 5E3 Deluxe, the 5G9 requires re-biasing when output tubes are changed — something made more convenient with a bias pot on the underside of the chassis.

Removing the upper back panel reveals a meticulously hand-wired circuit using Jupiter yellow and “Red Astron” signal capacitors, carbon-comp resistors, and other high-end components. Custom-wound Heyboer power and output transformers and a Hammond choke populate the other side of the chassis, and the cabinet carries a 12-inch Weber Alnico 12A125 30-watt speaker, a reproduction of the original Jensen P12Q.

Tested with a Fender Telecaster and a Gibson ES-335 electric, the Fullerton 5G9 quickly reminded me of the originals I’d owned in the past, with a robust clean tone that takes some hammering before it starts to break up, and that rich, thick tweed sound that so beautifully complements single coils and lower-wind humbuckers alike.

With the master volume maxed (and therefore ostensibly out of the circuit), you have to push the Bright channel with the 12AY7 engaged pretty hard to elicit any breakup, but it’s tactile and dynamic when it comes. By then, the amp is reasonably loud for an 18-watter, although it shouldn’t be overpowering in venues of 100 seats or more.

For smaller rooms, or for more tolerable grind with the volume all the way up, the PPI master volume does a great job of taming the decibels without impeding the amp’s voice, and proves a fantastic addition as a result.

From here, of course, there are several other avenues of gain to tap — either individually or layered up — via the 12AX7 setting (a notable jump in volume and breakup, if not excessive), the extra gain stage on the tone control’s push-pull, the Marshall-voiced Normal channel, or indeed the two jumpered together with all of the above. Get the latter setting cooking and dial the master to taste, and there’s no end of singing, touch-sensitive overdrive to be had — plus endless fun along with it.

To my tastes, the tremolo functions best on cleaner, edge-of-breakup, or just-over-the-edge gain settings, where it’s sweetly rounded, rich, and atmospheric. It’s a great example of why so many players hail tube-driven bias-modulated trem as the crème de la crème of this effect. Applying it to heavier drive settings still yields some wild and evocative sounds, though, and boatloads of expression in the swamp-blues arena.

Add in the versatility of the negative-feedback switch and switchable rectifier, and there’s a deceptive number of voices lurking within this unassuming tweed combo. All in all, it greatly honors an underappreciated original that has only recently found the spotlight, and proves a toneful and portable combo that myriad players are likely to dig immensely.

SPECIFICATIONS

CONTACT Cutthroataudio.com

PRICE $3,195 street

CHANNELS 2

CONTROLS Bright Volume, Normal Volume, Tone, Tremolo Speed and Depth, Master Volume; switches for 12AY7/12AX7 Ch1, channel jumpering, added gain stage

POWER 18 watts

TUBES One 12AY7, three 12AX7s, two 6V6GTs, one 5AU4GB rectifier

EXTRAS Footswitch for tremolo, solid-state/tube-rectified switch, three-way negative feedback switch, switch for 4/8/16Ω speaker output

SPEAKERS One 12" Weber Alnico 12A125

WEIGHT 35 lbs

MADE IN USA

PRO A great sounding homage to the originally last-iteration of the tweed Tremolux, with several clever mods increasing its versatility exponentially.

CON It comes at a high price, although not an unreasonable one for the quality of components and workmanship.