An all-analog ’60s-inspired tremolo marries harmonic and optical circuits that can be used independently or blended to generate phasey, throbbing magic.
Spans practical, convincing vintage trem tones and the utterly weird. Hefty build quality.
Big footprint.
$299
Jackson Audio Silvertone Twin Trem
jackson.audio
Almost any effect can be used subliminally or to extremes. But tremolo is a little extra special when employed at its weirder limits. Unlike reverb or delay, for instance, which approximate phenomena heard in the natural world, tremolo from anything other than an amp or pedal tends to occur in the realm of altered states—suggesting the sexy, subterranean, and dreamy. Such moods can be conjured with any single tremolo. Put two together, though, and the simply sensual can be surreal. Modify this equation by mating two distinctly different tremolo types, and the possible sound pictures increase manifold.
The all-analog, U.S.-built Jackson Audio Silvertone Twin Trem accomplishes this by combining a syrupy harmonic tremolo—the likes of which you’d hear from an early-1960s brown-panel Fender amp—and an optical tremolo like that in a Silvertone 1484 Twin Twelve amp or black-panel Fender. Both effects can be used independently, but it’s when the two are blended that the Twin Trem shines.
Doppelganger Effect
The Twin Trem’s optical and harmonic circuits are obviously not identical twins, but each is operated via its own 3-knob array consisting of speed, depth, and a smaller volume knob that will boost or cut the output of the individual circuit. Both tremolo types modulate at speeds slower than what you hear in amplifier equivalents. I don’t have a Silvertone Twin Twelve tremolo on hand for comparison. But the slowest speed from a mid-1960s Fender optical tremolo matched the rate of the Twin Trem’s optical circuit at about the midpoint of its range. At its slowest, the optical side will cycle through minimum and maximum volume in just a little under a full second, which feels molasses-slow, stretching and enhancing the ramping effect. Maximum speeds on the Twin Trem are closer to the maximum on the old Fender. But that’s still a pretty rapid modulation rate and the Twin Trem’s range-y depth controls make fast modulations sound extra alien.
If you’re sensitive to such things, the dedicated volume controls are great for overcoming the perceived volume drop that goes with any tremolo. There’s much more gain available than what you need for that purpose, and slathering on the volume gives the pulses a burly quality that’s tough but can obscure some nuance. The ability to create disparate volumes for each circuit means you can slightly foreground one tremolo type or the other, opening up an even wider tone palette and highlighting unique interrelationships between modulations.
Double Shots Make Dizzy Daze
The Twin Trem’s optical tremolo side (if you open up the back you can watch the pulsing diode that activates the opto-resistor) exhibits the throbbing tendencies one associates with black-panel Fender amplifiers. In fact, the Twin Trem sounds uncannily like the old Vibrolux I used for this test, but with more speed, range, and intensity. On its own, it’s a convincing stand-in for a 1960s Fender, Gibson, or Silvertone circuit.
One of the coolest things about the harmonic tremolo is how it often doesn’t sound like tremolo at all. In a harmonic tremolo circuit, high and low-frequency bands are split and volume-attenuated out of phase from each other, creating a bubblegum elasticity in the modulations. At slow speeds the harmonic tremolo’s phasey attributes take center stage (clip 1). And though the modulation texture is less swirling than what a simple phaser produces, the more vowel-like pulses lend a sleepy, mysterious aura to the modulation.
Though I did not use the pedal in stereo, I did utilize the effects loop, inserting a delay between the harmonic and optical tremolo, creating a little extra wash in the harmonic tremolo sweeps (clip 2). You can go crazy with possibilities here: How about inserting a multiple-tape-head-style delay for maximum syncopated mayhem? But the most traditional application for the effects loop is to simulate the reverb-into-tremolo order found in many mid-1960s amps. Again, it’s a great option when you need ’60s reverb/tremolo combo amp vibes and there’s no such animal around.Clip 2, which showcases the Twin Trem’s effects loop, also captures the two tremolos working together. And even at this fast-twitching speed you can hear the phaser-like wash softening the front end of the harder optical pulses that are situated downstream. Some dual-trem settings can produce chaos. But the best ones are thick, eerie, and propulsive in ways that can completely transform a song’s ambience.
The Verdict
The Twin Trem is just short of 300 bucks, and it’s easy to rationalize such a significant expense when you consider that you get two distinct tremolo sounds that you can mix, match, and switch between very readily. Maximizing the investment probably requires a little extra thirst for the unusual. Not all combined settings are money. Some rhythmic syncopations will drive you batty, and without the benefit of digital control you can disappear down little rabbit holes trying to find an elusive, perfect subdivision between modulation tempos or replicating a texture you found the previous week. These are very minor traps, however. In general, the Twin Trem is forgiving and easy to use. And if you get in a meditative place with the pedal, and let it do the driving from time to time, the riffs will practically write themselves.
1950s gibson les paul
Ever been frustrated by how the two volume controls interact on a dual-humbucker axe? Here’s how to make them work independently.
Here's an easy but effective mod for Les Paul slingers that solves a problem they've been living with since the model's introduction more than a half century ago. This project also applies to most other guitars with dual humbuckers, individual master volume and master tone knobs for each pickup, and a 3-way pickup selector switch.
The problem (or not).
The Les Paul circuit dates back to the mid '50s. It has changed slightly over time—Gibson used several different tone caps and experimented with tone-pot wiring—but essentially, modern Les Pauls employ the original wiring.
The Les Paul circuit dates back to the mid '50s. It has changed slightly over time—Gibson used several different tone caps and experimented with tone-pot wiring—but essentially, modern Les Pauls employ the original wiring.
One thing Gibson did not change was the concept of coupled volume pots. You know how this works: With an independent pair of controls for each pickup and a 3-way toggle switch, you can dial in your lead volume and tone using the bridge pickup, set up a rhythm tone using the neck pickup, and then quickly change from lead to rhythm and back using the 3-way switch. This works great—two preset sounds at your fingertips.
Les Paul players know what happens when you use the middle position of the 3-way switch: Backing down just one of the volumes to zero shuts off the entire guitar.
But Les Paul players know what happens when you use the middle position of the 3-way switch: The pickups are wired together in parallel, so when both pickups are engaged, rolling down the volume of one even slightly while leaving the other fully open makes the latter much louder than its mate. Even worse, backing down just one of the volumes to zero shuts off the entire guitar.
Why is this? Because the two volume controls are not decoupled, they interact. With a passive circuit like this, it's just the nature of the beast. Consequently, the dual-humbucker world divides into two opposing camps: The first doesn't consider this interaction a problem. It's simply part of the game—get used to it. The other camp regards this interaction as a system error and tries to eliminate it.
Now, the only real solution for this problem—assuming it's an issue for you—is to switch to active circuitry. All other "solutions" are compromises that may or may not appeal to you. You must let your ears decide.
Swap it out.
It's easy to wire a Les Paul so the volume controls work independently: You simply wire the volume pots backwards. (This is how some Rickenbacker guitars and early Fender Jazz basses are wired.)
Wiring diagram courtesy of singlecoil.com.
First, study the wiring diagram shown here. It represents the modern factory wiring typically found in Les Pauls. The black wires are ground; the white wires are the hot connections from the pickups and to the output jack. The black wires that run from pot to pot form the "ground bus." Be careful not to close this ring—leave the connection between the two volume pots open, as shown in the wiring diagram, otherwise you'll create a perfect antenna that picks up all kinds of funny noises. (For a noise-free circuit, it's very important that the ground bus uses a solid, not too thin wire and strong soldering spots.)
Now, simply interchange connections 3 and 2 on both volume pots, including the tone cap connections. That's it! Leave all connections on the tone pots untouched. You've now wired both volume pots backwards, thus decoupling them.
Time to network?
There's a big downside to this mod: When the pickups are wired backwards, they "see" less resistance, and the output impedance rises. This results in dramatic treble loss when you roll back the volume. It's an idiosyncrasy of passive guitar systems: When you turn down the volume, even just a bit, treble loss is not proportional: A small cut in volume creates a far greater loss in treble response. And the treble loss is even worse when the volume pots are wired backwards.
You can combat this by adding a treble-bleed network between the input and output of each volume pot. This usually consists of a small capacitor, often with a resistor in series or parallel. Simply solder the treble-bleed network between lugs 3 and 2 on each volume pot and see if it sounds right to you.
As far as capacitor and resistor values, that depends on how much treble you like. Some people prefer using a capacitor only (aka "treble bypass cap"), while others like a cap with a resistor in parallel. A useable range for the cap is from 220 pF to 680 pF; a resistor wired in parallel can range from 150k ohm to 330k ohm. A popular choice for a cap-only solution is 330 pF. For a network solution, many players like a 470 pF cap with a 330k-ohm resistor wired in parallel. You could start with this and see what sounds best to you. Small silver mica caps sound excellent for this mod.
Remember, passive circuitry can never add anything that isn't already there, but it can reshape the tone by deemphasizing certain frequencies, which makes others more prominent. This treble-bleed network filters bass so the highs are more pronounced.
Until next time, keep on modding!
[Updated 9/28/21]