After reinventing analog chorus, vibrato, and phaser effects with the Warped Vinyl and Wombtone (and newly released Warped Vinyl MKII & Wombtone MKII), Chase Bliss Audio have now tackled the prototypical modulation effect with the Gravitas Analog Tremolo. All the familiar Chase Bliss Audio control flair is here: ModuShape, 6 surface knobs, 3 parameter flip-switches, 1 preset flip-switch, 2 foot-switches, and 16(!) dip-switches mounted to the top side of the pedal. Before we delve into what all this does, it should be obvious that this pedal offers quite a bit more functionality than your old in-amp tremolo. To those of you suffering from knob-o-phobia, a plethora of classic and cutting edge tremolo sounds are available from the Gravitas even if you just stick to using a few of its surface controls. But more on all that in a moment. Here’s a full feature rundown before we dive into our Chase Bliss Audio Gravitas review to see if it’s the best analog tremolo pedal around.
- All-analog signal path.
- Ramp control knob can be set to control any of the 5 parameters (Volume, Tone, Rate, Depth, Sway) individually or simultaneously via dip switches on the back of the pedal. Controls the ramp time in which this takes place.
- Drive (Ramp) control knob controls the input gain of avery clean, beautiful, and transparent boost when no Ramp dip-switches are in use.
- Volume control knob sets the output level of the effect. This is a little different than the other Chase Bliss Audio pedal volume knobs. It should be pretty much dimed, with the level set with the Drive control. The main purpose of having this knob is so that you can set up a second tremolo (via Ramping), and then adjust the depth of it.
- Tone control knob is a wide ranging tone shaping tool. When set to noon, the pedal is transparent. Clockwise for a brighter sound and counterclockwise for a smoother, mellow, dark sound. This circuit is also the basis for the harmonic tremolo as that effect is achieved by modulating between high and low pass filters.
- Rate control knob controls the rate of the tremolo effect – can get super fast. Can be overridden by the tap tempo switch.
- 1 – 2 – 4 (3 – 6 – 8/S – B – H) toggle switch sets the tap division for tap tempo. A dip switch on the back accesses the “3 – 6 – 8” divisions. Another dip-switch allows this switch to select between Standard, Both, and Harmonic tremolo modes.
- Depth control knob sets the depth of the tremolo effect. Crank if for modulation going all the way to silence.
- Sway control knob sets the center point of the modulation. Set it counterclockwise to make the wave ramp up quickly and down gradually. Set it clockwise to make the wave ramp up gradually and down quickly. Set it at noon for a perfectly symmetrical wave.
- Left Wave Shape toggle switch sets the first half of the wave modulation. Left for sine, middle for triangle, right for square.
- Right Wave Shape toggle switch sets the second half of the wave modulation. Left for square, middle for triangle, right for sine.
- Bypass foot-switch activates or bypasses the effect via true relay bypass. Can by changed to a momentary bypass via a dip switch in the back of the pedal.
- Tap Tempo foot-switch sets the tap tempo and always honors the last two stomps.
- Preset toggle switch recalls presets. Middle position reflects current knob positions, right position recalls right preset, and left position recalls left preset.
- Exp/CV input jack allows expression pedal or CV control of parameters selected via dip switches on back of pedal. When no parameters are set to Ramp, it manually controls the Waveform.
- Tap/MIDI input jack can be used for tap input or output with a regular ¼” instrument cable. It may also be used to interface with the pedal via an Empress Effects Midibox.
- Powered by 9-volt battery or 9VDC power adapter. Can also be run at 18-volts for more headroom and output.
- Volume, Tone, Rate, Depth, and Sway dip switches on the left side simply turn that parameter on or off for ramping or expression pedal capability.
- Volume, Tone, Rate, Depth, and Sway dip switches on the right side control whether the parameters rise or fall in ramp mode. This also affects the direction of movement with an expression pedal.
- Bounce dip switch makes parameters go back and forth (i.e. modulate) or ramp and hold.
- Mode dip switch allows left flip-switch to select tap divisions or tremolo mode.
- MoToByp dip switch activates momentary bypass, activating pedal only when Bypass foot-switch is pressed in.
- Tap Control dip switch allows tap tempo to modulate Ramp rate (r) or tremolo Rate (p). Bounce needs to be on to modulate Ramp speed.
- Tap Division dip switch selects from “1, 2, 4” tap divisions (1) or “3, 6, 8” tap divisions (3).
- Sweep dip switch selects where Ramp sweeps. In “t” (top) the ramping (or expression control) will occur between the current Ramp knob position and the max position (fully clockwise). In “b” (bottom) the range is set between the current knob position and the minimum position (fully counterclockwise).
Sound & Performance:
I’m going to cover the functionality of this pedal gradually. We’ll start with the traditional sounds it offers and the simplest aspects of its controls and slowly delve into the more complex stuff.
Classic Tremolo Reinvented
This is where the Gravitas excels, or should I say, shows its gravitas. Throbbing volume modulation oozes out of this pedal with classic and new sounds being very easy to dial in. There are 3 tremolo modes available: Standard, Harmonic, & Both. Standard mode is the classic style tremolo effect, and thanks to ModuShape (see below), you can achieve a smooth volume pulse or unconventionally offset and jagged warbles. Harmonic mode allows the LFO to modulate the Tone of your signal for a subtle and unique tremolo-style filtering effect.
The “Both” setting is where things get really interesting. The Gravitas’ combination of Standard tremolo mode with the unique Harmonic mode is a most welcome twist on tremolo design as it provides a dynamic tone adjustment as the volume swells for a blooming effect in the upper frequencies. You can use the Tone knob to choose just how bright the tremolo gets at its peak. The effect is subtle yet beautiful; while I thought it might be an interesting novelty, it quickly became my preferred mode.
This has become a staple of the Chase Bliss Audio pedals released so far (see Warped Vinyl MKII & Wombtone MKII) and is a brilliant and simple way to set the LFO waveform for modulation effects. For a quick “classic” tremolo sound, simply set the Depth and Sway to noon and flip the 2 ModuShape toggle-switches to Sine (facing away from each other). From there you can adjust the Depth to taste. Pulling the flip-switches to their middle positions brings in a slightly sharper Triangle waveform, a great classic trem variation when used with lower Depth settings. Setting the switches inward to Square produces a hard trem effect that gets pretty choppy when maxing out the Depth. While it isn’t the most machine-like, gated chop I’ve heard in a tremolo (most likely due to the particular nature of this pedal’s analog design), it’s still more than adequate for producing those jagged stuttering trem effects, especially when used in a mix with other instrumentation. Also, using the various waveform halves in combination and exploring the Sway knob settings (which lop-sides the waveform) will yield some inspiring, unorthodox sounds.
Drive/Volume & 18-Volt Operation
An interesting thing about the Gravitas is its Drive/Volume knob arrangement. The Drive knob controls a clean boost gain stage located before your signal is fed into the tremolo effect. The overall output is set post-tremolo with the Volume knob. Chase Bliss Audio advises in the Gravitas manual to dime the Volume knob and use the Drive for setting your output level. As stated in the manual, “the main purpose of having this [Volume] knob is so that you can set up a second tremolo, and then adjust the depth of it.” You can use the Ramp function to modulate the Volume, thus achieving 2 separate tremolos. (You could also run 2 Gravitas pedals in series for synchronized, rhythmic tremolo sounds via MIDI Clock. I tried it. Fun stuff.)
In the Gravitas manual Chase Bliss Audio also mentions under the “Drive (Ramp)” section how using the pedal with 18v can result in “more headroom and output”. Since it specifically mentioned this in relation to the Drive knob, I spent some time comparing running the pedal on 9-volts (via battery) and 18-volts (via power supply). With the Drive knob rolled all the way down, the difference is negligible. The voltage difference doesn’t really affect how the Volume knob performs. But as you increase the Drive it becomes apparent that the different voltage does have more of an impact on the overall output and high-end presence of your sound. This leads me to prefer using the Gravitas at 18-volts with the Drive knob at higher settings. I’ll then use the Volume knob for setting the output (contrary to the manual’s recommendation) as the benefits of 18-volts are most noticeable to my ears with higher Drive settings. At this point you could also roll the Depth all the way down and use the Gravitas as a hi-fi, 18-volt clean boost with complementary Tone control.
It’s important to understand that the Drive essentially pushes a “hotter” signal into the tremolo when used at high levels. It doesn’t quite get dirty on it’s own, but if you want your overall sound to be as clean as possible, try dialing it down a bit. Also, while I personally prefer the 18-volt sound of the pedal, the Gravitas still sounds great at 9-volts. 18-volts will be mainly worth considering if you just really want to extra headroom or if you really need that little extra volume output (which is useful if you use extreme Rate settings as they tend to reduce the overall output level, typical of all tremolo pedals).
This is where things get even more interesting. Another Chase Bliss Audio hallmark, the Ramping functionality lets you modulate parameters by setting them to “ramp” via dip-switches for each of the 5 parameters (not including Drive). With the Warped Vinyl MKII & Wombtone MKII, I find myself getting pretty wacky with the myriad ramping possibilities, but with the Gravitas I find more restrained ramping to be most effective. For example, simply modulating the Volume by setting it to Ramp and “Bounce” up and down produces a double-tremolo effect. (The left preset showcases this.) I also like to set the Tone control to a long “Ramp and hold” with Both mode (Standard & Harmonic) so that it gradually increases to the brighter sound set via the Tone knob. You could also have it Bounce back and forth for a little tonal variation behind your tremolo. And it’s fun to get a little funky with the Rate & Depth to go from a dry and slow to wet and fast tremolo.
The Gravitas lets you save 2 flip-switch selectable presets to access from the surface. If you want to go deeper, you can save and recall 122 additional presets via MIDI. This is a godsend if you want to use this pedal in a MIDI rig and select your presets via MIDI. You can also control the knob parameters via CC messages. There’s even a CC for changing the Tap Division. I was able to program some Tap Division automation in Ableton Live for some pseudo-Goatkeeper style pattern tremolo effects. Also, as I mentioned previously when running 2 Gravitas pedals in series, MIDI Clock can help keep the pedals in sync. I used the Molten Voltage Tempode to keep both pedals in time. You could theoretically create and recall presets on 2 pedals to reproduce whatever crazy tremolo patterns you come up with.
A few notes about the size of this pedal and its practicality in use. It never ceases to amaze me how much Chase Bliss Audio can stuff into a reasonably standard sized pedal enclosure. (Notice how even the foot-switches are mounted at an angle inside to allow just a little more room for the PCB.) Looking from the the outside, it may appear concerning to have the Tap Tempo foot-switch so close to the Bypass foot-switch, but in use this isn’t too much of an issue. You’ll have to use the right edge of your shoe to tap in the tremolo to the beat, but then a hearty stomp on either just the right foot-switch or the general foot-switch area will activate it. If you’re using the Rate knob to set the tempo, you don’t need to worry about accidentally pressing the Tap foot-switch when activating the pedal as a single press won’t change the tempo. Still, for maximum utility, the Gravitas performs brilliantly with MIDI and is how I’d most recommend using this pedal in your guitar rig.
Chase Bliss Audio have pretty much covered the analog modulation essentials as this point with the Gravitas rounding out their pedal lineup. While my personal tastes usually lean towards super aggressive, choppy tremolo effects, for classic analog tremolo tones (in mono) this pedal is tough to beat. As I spent more time with it, it really won me over, mainly thanks to the innovative Harmonic mode which gives this pedal a unique sonic edge over other basic tremolo guitar pedals. And the Gravitas is an especially great compliment to the Warped Vinyl MKII for capturing an old timey, vintage vibe. Speaking of vibes, a Uni-Vibe style of pedal would be perhaps the only other modulation pedal I can think of that I’d like to see next from Chase Bliss Audio, but it’ll really be interesting when this company finally releases a delay pedal or ventures into the realm of fuzz or distortion.
The Gravitas is another winner from Chase Bliss Audio. Let’s see the final result.
The Chase Bliss Audio Gravitas is one of the most beautiful sounding analog tremolo pedals I’ve had the pleasure of playing. The pedal’s combination of Standard tremolo and Harmonic mode produce some of the most inspiring and unique tremolo sounds around. As a classic tremolo the Gravitas excels, but the extra subtleties really make this pedal something special. And if you like having a ton of presets, MIDI control, and perfectly synced tremolo via tap tempo or MIDI Clock with your classic tremolo sounds, the Gravitas should be the next pedal on your must-buy list. In terms of a mono-only analog tremolo, this is the best one there is.
That concludes our Chase Bliss Audio Gravitas review. Thanks for reading.
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