Fractal Audio AMP models: Jazz 120 (Roland Jazz Chorus 120)

yek

Contact Fractal for your Custom Title
* EDIT: Up-to-date information is available in Yek's Guide to the Fractal Audio Amplifier Models *

Jc120.jpg


JAZZ 120: based on Roland Jazz Chorus JC-120

Welcome to the only current Fractal Audio model that’s based on a solid-state amp: the venerable Roland Jazz Chorus JC-120.

Back in the 80s I owned one, even though I didn’t play jazz. There were a lot of these amps around, especially in the jazz and jazz-rock scene. I remember seeing Billy Cobham’s guitar player using one. Although it’s an ultra-clean amp by itself, it handles drive pedals well. I acieved great overdriven tones with my JC-120 using an original H&K Tube Factor pedal or a Tubescreamer. Famous JC-120 players include Andy Summers, Alex Lifeson, and many more.

The JC-120 enjoyed a revival in the metal and nu-metal era. Bands such as Metallica and Limp Bizkit used them to for clean parts in their songs.

These amps are associated with ultra-clean tones and its famous built-in chorus/vibrato. It’s a true stereo-chorus. Roland calls it their Dimensional Space Chorus. This seems to refer to Roland’s Dimension chorus, but the JC-120’s built-in chorus circuit is identical to the famous vintage CE-1. As a matter of fact, the JC’s chorus predates the CE-1.

The chorus isn’t a part of the amp model. To replicate it in our Fractal devices, use the CHORUS block, set it to CE-2 and place it after the AMP block to keep it stereo.

Javajunkie replicates the famous CE-1 chorus.

Roland (current JC-120):

“First introduced way back in 1975, the JC-120 Jazz Chorus is one of the few guitar amps that can truly be called a legend. Roland’s long-standing flagship is universally recognized by pros as the benchmark in clean guitar sound, and its rich tone and famous built-in stereo chorus effect have been heard on countless popular songs over its long history. Now celebrating 40 years of continuous production and counting, the JC-120 remains the undisputed “king of clean,” and the enduring choice of serious guitarists everywhere.”​

The 120 stands for 120 watts, which is 60 watts per side. The amp has two channels. The Normal channel 1 doesn’t have any effects, while the Effect channel provides chorus, reverb and drive. Because of the chorus everybody uses the Effect channel. It has two inputs per channel.

The JC-120 does provide a Distortion control. But the distortion created by that control on channel 2 sounds so terrible, so laughable bad, that it should be forbidden by law to use it.

The amp’s controls: Volume, Bass, Mid, Treble, Bright switch. Not modeled: Distortion, Chorus, Reverb.

AFAIK the real amp has no Master Volume control. But the model’s Master doesn’t default to 10, which accounts for the model’s very low output. I believe this may be an oversight, so I always turn up the Master control to 10. I also engage the Bright switch. It's been a while since I tested this model, and with these settings it delivers a very nice clean tone with body.

Manual

For its stereo output the JC-120 relies on two 12” Roland speakers (silver Alnico). We used to have these available as stock cabs before firmware 18, but they were replaced. Cab Pack 21 provides JC-120 IRs. Or try other Alnico stock cabs, such as stock cab #94.







 
Last edited:
I use this amp for a spanky clean funk preset. Sounds killer for when you want zero breakup from the amp. I almost always use a compressor with it for a super percussive attack. James Brown anyone?
 
Hi Friends,

I have Roland Jazz Chorus 120 and I could not simulate well in Fractal Axe FX II XL+, someone can help me please?

Thanks
 
I had one of these back in the day (late 90's). As clean as it gets and blindingly loud. Like a Twin Reverb without a soul.

I remember running into these amps over and over again in Music School labs as the "house amp". Maybe it's branding as a "Jazz" amp convinced administrators that it was more appropriate than a rockin' Fender or Marshall.
 
I have the roland spirit 40, is a practice little brother from that era and sports the same 12'' roland heavy duty speaker with aluminum cap, very well built, I had many offers for sell it but it's a keeper, love the cleans!
 
I still have my '87 JC-120, and it ain't going anywhere. I still haven't found an IR that replicates it on FRFR without a bunch of EQ, and even then, it's only marginally close. That said, I LOVE playing may XL+ directly into it's main ins....

RR
 
I haven't found anything that replicates playing in the room with an open backed cab of any kind, including my JC110.

But, lay down a track, and from the mix room, the Fractal holds its own and then some :)
 
Someone has a good Axe FX presets of JC-120?

Chorus is an important feature, which models of Axe FX Chorus would be the most approximate?
 
Played with this amp forever...cannot get it loud enough without clipping, really very quiet. Compared to other presets this one is really quiet. Adjusted both amp volumes, played with gain, even added compressor and filter with GEQ. Not many effects running compared with my other presets. Any help would be appreciated. Thanks
 
Played with this amp forever...cannot get it loud enough without clipping, really very quiet. Compared to other presets this one is really quiet. Adjusted both amp volumes, played with gain, even added compressor and filter with GEQ. Not many effects running compared with my other presets. Any help would be appreciated. Thanks
Try getting it where you want, and then adjusting all your other patches (via the Level control in the Amp block) to match it in loudness. Do this by playing at gig volume.

Problem solved :)
 
Played with this amp forever...cannot get it loud enough without clipping, really very quiet. Compared to other presets this one is really quiet. Adjusted both amp volumes, played with gain, even added compressor and filter with GEQ. Not many effects running compared with my other presets. Any help would be appreciated. Thanks
as mentioned the real thing doesnt have a master volume so turn that to 10 and adjust from there? if youre getting unwanted break up bring down the input gain and adjust the output volume knob to compensate
 
If you are looking for a solid state amp model to use for bass, you can emulate many of them using this amp and the requisite ir.

FwIW: I love the distortion of this model for Skunk Baxter type Reeling in the Years tone. That saturation switch and parameter can get you close to that AM radio distortion awesomeness. Everything has a use in the proper context.
 
Hah, I used to have a JC-120 and a JC-60 (single speaker, so the chorus sounded more flange-like than the actual stereo of the 120.)

I'd split the signal before the amps and play them in stereo with both choruses on -- talk about a lush sound! No argument about the distortion, I always used a Rat or my TS-808.

To me the defining characteristic that created the open sound was the fact that the amp created the stereo effect in the audio domain by using one speaker straight and the other with the vibrato.

TT
 
To me the defining characteristic that created the open sound was the fact that the amp created the stereo effect in the audio domain by using one speaker straight and the other with the vibrato.

TT

This is what I read as well. I emulate it by splitting the signal after the amp and sending the left straight through, and sending the right through a pitch shifter to detune it between -6 and -12 cents.

RR
 
Back
Top Bottom