Roland JC 40 Hiss - Any way to fix this?

**Daniel Gonzalez** · 07-24-2018, 08:59 AM

I have a brand new, about 2 month old JC 40. When I played it at Sam Ash, I could not notice the hiss, as it was very loud. I have passed the return day (45 days) and would really like to be able to use the amp at home, but the hiss is driving me nuts. I bought DV Mark Jazz to use at home instead, but would like some more volume and tone choices that the Roland has. Any suggestions? Can it be fixed? It cost like $600 and I am not using it. Help please.

**Jim Soloway** · 07-24-2018, 11:51 AM

That hiss has been part of the JC series forever. I was pretty shocked when I found out the JC40 had the same problem. Roland is generally a pretty good company and I thought for sure they would have solved this for the new generation of JC amps but no such luck. I don't know anyone who has ever solved this problem.

**jzucker** · 07-24-2018, 08:16 PM

I've written about this many times. Roland puts a really cheap speaker in the JC-120 and I once replaced them with JBL speakers. BIG MISTAKE. The increased high end made a bad hiss even more unbearable. Not to mention the thing weighed 100lbs (or so it felt like)

Roland's commitment to guitar products is puzzling. They could easily fix the power amp on the JC series. They seem to do the absolute bare minimum on all their products. The SY300 synth pedal is a perfect example. Great potential but no firmware update for 2 years. Their guitar synth products have marginally improved though many competitors have leap-frogged them. Pedals are mediocre. I do like the katana...

**rpjazzguitar** · 07-24-2018, 10:53 PM

I gig with a JC55 and use it at home too. Hiss doesn't bother me, apparently one of the real positives about high frequency hearing loss.

That said, I also have a Boogie Mark III - which has a fan. The fan is a zillion times louder than the JC55 hiss. Nothing wrong with it -- it's just that loud. The amp, when turned up does drown it out.

**cosmic gumbo** · 07-25-2018, 03:45 AM

I bought and returned a couple Roland amps in the search for one that didn't hiss. Crossed that brand off my list.

**Gitfiddler** · 07-25-2018, 02:16 PM

Interesting that the JC series has a hiss issue. I don't hear any unwanted noise from my Cube 80GX...even with its 'JC Clean' patch engaged.

Still not clear why Roland discontinued that series of amps.

**Doublea A** · 07-25-2018, 02:24 PM

I had a JC 120 which I bought around 2001 which I eventually sold because of this issue. I bought a Cube 60with JC emulator, the sound was close but not exactly a true JC sound. I bought a JC 55 about 3 years ago when I heard that the hiss had been solved. It wasn’t so I returned it to the store.

The long and the short is if you love that sound, you will need to deal with that hiss.

The hiss never bothered me in Live situations but drove me crazy when I tried to record.

**callouscallus** · 07-25-2018, 11:15 PM

Love my Jc120....nothing sounds like it. Hiss is no big deal to me personally.

**rolijen** · 07-25-2018, 11:58 PM

Originally Posted by Gitfiddler

Interesting that the JC series has a hiss issue. I don't hear any unwanted noise from my Cube 80GX...even with its 'JC Clean' patch engaged.

Still not clear why Roland discontinued that series of amps.

My old Jazz Chorus successfully got me through many, many gigs over many years but the hiss led me to sell it eventually. I too settled on a Cube 80gx and have been happy as a clam.

Roli

**Flat** · 07-26-2018, 01:38 AM

I played through a Jazz Chorus 60 for years in my salad days -- single speaker version of the JC120. Nothing but nothing had that chilly, crystalline, chorus, pedal-hungry high end. An analog delay pedal and that amp, and I was ready to play all kinds of music I didn't really want to. Flock of Seagulls my ass.

And yeah, the hiss. It would disappear in a band context, but in my bedroom trying to play something solo and sweet, what a vibe-harshing nuisance.

Roland has made some amazing gear. I don't get why they hang on to that hiss.

**Little Jay** · 07-26-2018, 07:27 AM

Sold my Cube 30x for the same reason. So Cube Cube 80gx has no hiss? Apparently they fixed it in the newer Cube series then!

**whiskey02** · 07-26-2018, 08:47 AM

My Cube 30 is dead silent as far as any background noise/hiss is concerned, and it is from the first year or two of production. I've not read anyone mention hissing with the Blued Cube series of amps, do they suffer from it?

**rolijen** · 07-27-2018, 12:25 AM

Originally Posted by Little Jay

Sold my Cube 30x for the same reason. So Cube Cube 80gx has no hiss? Apparently they fixed it in the newer Cube series then!

I have heard only mine so I’m not speaking for anyone else, but my Cube 80gx is dead quiet. And the JC Clean channel is glorious.

Roli

**vintagelove** · 07-27-2018, 10:04 AM

If you need to fix this, well, band aid it,

Get an attenuators that goes between the amp and speakers that will knock off some output volume.

Hook it up, lower the volume until the noise floor is acceptable, then crank the preamp into the power amp to achieve the desired volume.

Lets just hope the preamp isn’t noisy as well...

these are ok for the price

Carl's Custom Amp SPEAKER Soak 8ohm Power Attenuator | Reverb

**Alder Statesman** · 07-28-2018, 09:20 AM

An alternative could also be to drop a volume pedal or noise gate in the fx loop. I use a SuperSonic 22 which is a notoriusly noisy amp. Like the JC’s, it is not an issue live, but recording or living room volumes it would drive me to distraction. I added an MXR Smartgate and a Dunlop mini volume. Works great and may help with the JC as well.

**vernon** · 07-30-2018, 08:58 PM

Had a JC-120 for about a year... once the infatuation with that intoxicating stereo chorus wears off, the hiss really quickly becomes the obnoxious company that stays too long.

**plazc2** · 10-09-2018, 12:08 AM

Hissing problem solved

I applied it to jc 120

I connected the behringer denoiser snr2000 to the send effect, which works specifically for channel 2. The snr should be set rigorously so as not to affect the original sound too much. The Behringer is a simple noise door. It eliminates the hiss being able to handle with delicacy the envelope

Channel 1 remains intact. To play at home, I use channel 2. Live, the 1. Problem solved!

**Payne** · 03-09-2020, 11:34 AM

I have solved it this way for my JC-120 with great success - hardly no hiss to hear any longer.

It is a hardware modification

**Little Jay** · 03-09-2020, 06:56 PM

Impressive! It obviousy worked but mat I ask how you figured out what had to be different? What’s the reasoning behind the mod?

(I have a hissy Dynacord tube amp - model DA-16/v - and I would love to tame the hiss in that.)

*edit: I was too quick, you explain how the mod works in your vid ;-)

**Payne** · 03-12-2020, 08:10 AM

It works perfect now, so no reason to sell :-)

The speakers, IMO, are very good, the problem for the JC-120 is gaining up and down through the signal chain, which will add noise.

The solution that worked for me, was removing 20dB in the second preamp stage and compensating by using the high input jack, and turning up tone controls as much clockwise as possible.

It can be improved even more, if send/returns are not used. I have a solution for that.

There is still A LOT of gain the amplifier.

**crestone44** · 03-30-2020, 08:08 AM

Originally Posted by Payne

I have solved it this way for my JC-120 with great success - hardly no hiss to hear any longer.

It is a hardware modification

I have a JC40 on which I would like to attempt a similar mod.

Are you familiar at all with the JC40 board?

I think I could compare the two CDs and figure it out, but would also appreciate any guidance you may have.

Thank you!

**Payne** · 03-30-2020, 08:57 AM

I can look into it. Do you have the schematic or service manual for it?

**crestone44** · 03-30-2020, 10:28 AM

I have spent the last couple of hours online looking for a JC-40 schematic. I am convinced that it is probably easier to obtain nuclear reactor schematics at this point! Wow.

I just sent an email to Roland asking how to obtain a service manual and/or a board schematic. I will let you know how I make out. I certainly appreciate you willing to help out. While I have a bit of an electronics background, I think I am going to struggle identifying the equivalent changes for the JC-40 vs your JC-120 mods.

I know a lot of people love these amps but hate the hiss, so hopefully we can find a solution that anyone with basic soldering skills can employ.

Jeff

**Payne** · 03-30-2020, 11:45 AM

Yeah, I just tried the same without any luck, so let's hope that Roland can help - or maybe some local music store with repair shop?

**crestone44** · 03-30-2020, 02:38 PM

Well, I heard back from Roland pretty quickly and in a really nice manner, and with just a wee bit of corporate-speak, they told me to go pound sand. I'm still pushing back, since I am trying to solve their problem after all, but I'm not holding my breath.

Too bad, as I really like the amp, but it looks like I may have to consider turning it into an expensive 2x10 cab, or selling it.