The JAM Pedals Dyna-ssoR is an analog compressor pedal with just two knobs, built around the rare NOS CA3080 chip. Jam Pedals describes it as "a musical NOS CA3080 compressor that delivers vintage punch, satisfying squash and long sustain without flattening the life out of your tone"1. The maker says the circuit is tuned to control dynamics while keeping the instrument's original character and musical expression intact2, and positions it as combining the spirit of the classic Ross and MXR Dyna Comp circuits in a simple two-knob design234.
The name is a nod to its lineage: read it backwards and it says "Ross," the compressor whose circuit, alongside the MXR Dyna Comp, it draws on. Delicious Audio's reviewer Gus Green described the design goal as combining "the best of the MXR DynaComp and Ross Compressor, both considered legendary in the stompbox realm"5.
The controls
The front panel keeps it to two knobs, the same layout the old Ross and Dyna Comp pedals used.
| Control | What it does |
|---|---|
| Sustain | Sets compression and sustain1 |
| Level | Sets output, to match your bypassed volume or push the next stage16 |
JAM Pedals suggests using Sustain high for a thumpy, compressed attack and singing hold, or backing it down to gently control peaks while keeping your playing dynamics intact4. Delicious Audio's reviewer explained the Sustain knob in practical terms: "the more you turn the Sustain knob CW, the more your signal gets compressed which basically makes the loud sound quieter and the quiet sound louder, hence squashing the sound, emphasizing details, providing more overall length to sustained notes"5.
On the control set as a whole, Gus Green's verdict was that restraint pays off: with just the two Sustain and Level controls, the beauty of the pedal for him was that a little goes a long way5. He found that subtle Sustain settings improved his tone "immensely, adding life and detail," and that, unlike other compressors he had tried, the Dyna-ssoR could be pushed to extreme Sustain settings without ruining the tone5. He also gave it a try on bass and found it equally impressive there5, and JAM Pedals makes a dedicated bass version of the Dyna-ssoR as well5.
Power and bypass
The Dyna-ssoR runs on a 9V battery or a 9V DC center-negative supply, drawing only 5 mA2. That low draw means it is easy on a battery and simple to run from a shared pedalboard supply. Switching is true bypass, so with the pedal disengaged the signal passes through untouched2. The same power and bypass specs apply across the limited artwork editions364.
The power jack is center-negative, the standard for most modern pedal supplies. If you power it from a battery instead, the 5 mA draw2 means a typical 9V battery lasts a long time at occasional-use levels.
Ross and Dyna Comp roots
The Dyna-ssoR's circuit lineage is the heart of the design. JAM Pedals says it "combines the spirit of classic Ross and Dyna Comp circuits in a simple two-knob design that feels responsive at every setting"1. The compression itself comes from the NOS CA3080 chip, a discontinued operational transconductance amplifier; JAM Pedals says this rare chip "delivers the vintage attack, compression and sustain associated with classic compressor designs"2. The same CA3080 compression and sustain section also appears inside JAM Pedals' Pink Flow pedal7.
On That Pedal Show, the channel compared the Dyna-ssoR against a 1970s MXR Dyna Comp in a short Effector Du Jour segment published 27 February 20248. Dan of That Pedal Show called JAM Pedals' take on the format a standout:
"Jam Pedals makes perhaps our favourite modern pedal compressor inspired by the classic MXR Dyna-Comp."
The artwork editions
JAM Pedals sells the Dyna-ssoR in limited hand-painted artwork editions alongside the standard pedal. Each is the same circuit with different paint: the maker's own line is "Same sound, different artwork"6. Every limited artwork pedal is a one-of-a-kind hand-painted piece, and the pedal you receive will differ in detail from the photos shown2.
| Edition | Notes |
|---|---|
| "Relic" Dyna-ssoR | Limited hand-painted artwork version36 |
| "Lunar Trails" Dyna-ssoR | Limited hand-painted artwork version3 |
| "Achenbach" Dyna-ssoR | Artwork by The Simpsons artist John Achenbach; listed as sold out46 |
The artwork editions carry a regular price of £264.00 GBP, against the standard pedal's £199.00 GBP listing4632. The maker's B-stock listing shows the standard pedal at a £169.00 GBP regular price, so the two maker pages disagree on the standard pedal's price; both figures are as listed on 25 October 20262.
B-stock Dyna-ssoR units are pedals that did not pass JAM Pedals' cosmetic quality check. The maker says they are otherwise brand new, in 100% working order, and ship in the original packaging with the life-time warranty2.
Who plays one
JAM Pedals lists David Torn and Dweezil Zappa among the artists using the Dyna-ssoR1, and Torn's own artist page on the maker's site names the pedal among those he uses9. Joey Landreth is quoted on the maker's artist page saying "The Dyna-ssoR is such a great compressor"10.
For players comparing compressors, the Dyna-ssoR sits in the vintage two-knob camp rather than the multi-band or studio-style camp. Its appeal, as both the maker and reviewers frame it, is a simple Sustain-and-Level interface, a classic CA3080 squash, and tone that holds up even at heavy compression settings1.
Videos
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Questions
Does the JAM Dyna-ssoR take a battery?
Yes. The Dyna-ssoR runs on a 9V battery or a 9V DC center-negative power supply, so it works either way. Current draw is a low 5 mA, which is easy on a battery and simple to power from most pedalboard supplies.
Is the Dyna-ssoR true bypass?
Yes. JAM Pedals lists true bypass switching on the Dyna-ssoR and on all of its limited artwork editions, including the Relic, Lunar Trails and Achenbach versions. When the pedal is off, your signal passes through without buffering.
What chip does the JAM Dyna-ssoR use?
It is built around the NOS CA3080 chip, a discontinued part that JAM Pedals describes as delivering the vintage attack, compression and sustain associated with classic compressor designs. NOS means new-old-stock: unused original chips rather than modern reissues.
Who uses the JAM Dyna-ssoR?
JAM Pedals lists David Torn and Dweezil Zappa among the artists using the Dyna-ssoR, and Joey Landreth is quoted on the maker's artist page calling it a great compressor. Delicious Audio's reviewer also found it equally impressive on bass.
What is a B-stock Dyna-ssoR?
B-stock units are pedals that failed JAM Pedals' cosmetic quality check but are otherwise brand new and in 100% working order, shipped in the original packaging with the life-time warranty. In other words, a cosmetic blemish rather than a functional difference.
What circuits is the JAM Dyna-ssoR based on?
JAM Pedals says it combines the spirit of the classic Ross and MXR Dyna Comp circuits in a simple two-knob design. Delicious Audio describes it as combining the best of the MXR DynaComp and Ross Compressor, both considered legendary in the stompbox realm.
Sources (10)
- Dyna-ssoR, JAM Pedals (www.jampedals.com)
- Dyna-ssoR B-Stock, JAM Pedals (www.jampedals.com)
- “Lunar Trails” Dyna-ssoR, JAM Pedals (jampedals.com)
- “Achenbach” Dyna-ssoR, JAM Pedals (jampedals.com)
- Guitar Pedal Reviews: JAM Dyna-ssoR Compressor/Sustainer, Delicious Audio, 2019-11-12
- “Relic” Dyna-ssoR, JAM Pedals (jampedals.com)
- Pink Flow, JAM Pedals (jampedals.com)
- JAM Pedals Dynassor & ’70s MXR Dyna Comp Effector Du Jour, That Pedal Show, 2024-02-27
- David Torn, JAM Pedals (www.jampedals.com)
- Joey Landreth (the Landreth Bros), JAM Pedals (www.jampedals.com)
Dweezil Zappa
Jim Campilongo
