Marshall JFX-1

G'day from Australia. Can you guys in this forum help with some technical stuff. At long last I've finally got hold of a JFX 1. I run this with my JMP 1 into 80/80 Valvestate along side a JCM 800 into two 4 x 12 cabs. As you guys are aware there is an effects control on the JMP 1 (0 - 12). I always run this setting at 6. Now since using the JFX I find I have to dial up closer to 10 - 12 just to the effects more clearly. I know there's a mix control on the JFX but this doesn't seem to affect anything. The JMP instructions state that the lower setting on the effect patch is suited to modulation effects and yet its behaving the opposite for me. (It could be possible that the JMP needs attention??) Can anyone suggest patch settings for both the JMP and JFX with say chorus and delay for a crunch tone? I would really appreciate some advice as Marshall are yet to get back to me. It could be something really simple but I just can't see it!!

Easy, with a little tweaking you get sound.
Editing is kept easy as well, 3 ways to tweak your lover.
Marshall has all it's manuals available on their site.

I use it with a JMP1 and a 9200, for they are made for eachother.
Very '90's rock sound, but smooth sounding, no noise.
Not outstanding effects, but more than sufficient for live use. (and because of MIDI ultimate handy)
I have better effects for studio use.

Mine is fine, but hey, it is still a '90's product. Don't expect eternal life, for the quality of components in this era was not very good. (but i'm glad it is still British made)

Marshall is known for its outstanding service, but it is still a discontinued product, and the storeshelves are empty, so no parts anymore.
When it is dead, buy a new one.

I am not the type for multi effects, but also will not take priceless works of art (read expensive and very rare vintage effects) to the stage, to be soaked in beer, sweat and blood.
It is the right guy for the job.
It seems it has the same build-up as the Rocktron Intellifex, so if it gets extinct we have another candidate for the job. (good & cheap)
I really love the MIDI possibilities, and encourage every guitar player to find out about it.
No 35 stompbox tapdance anymore, but 1 kick to your saved setting. (from clean with chorus and delay to total distortion with delay and slightly reverb in 1 kick)
It isn't the queen, but the handy nephew.

Very easy to use,

Really good, for the price I paid.
basic setup - Marshall 6100 Head preamp/Mesa Boogie Mark IV preamp through A/B midi switching. Left/Right output to Marshall/Boogie poweramps. Marshall powers two original 1968 100W 4x12 cabs (A and B) with greenbacks all around. Boogie's a combo fitted with an EV and a custom bass reflex extension cab fitted with a V30. Guitars range anything from a 52 Fender Tele to a ESP Horizon. I found it quite easy to get a good sound from the unit. I also prefer the JFX-1 to the Boogie's spring reverb since it colours the sound to much.

not even one problem, I bought it in 1995.

I requested some circuit diagrams for the 6100 so I can modify it. It was send the next business day.

style of music: Blues/Rock/Metal/Clasical. It works well with everything I have played.

easy to adjust

no noise
warm sound

I use it on gigs
never bad

If it were stolen or lost??? I maybe buy an TC G???major

couldnt be simpler, great for getting the basic sounds, dont need a manuel to work this unit

telecaster and strats, also sho bud pedal steel, peavey nashville 112 combo, jfx1 into loop clean sounds are so natural and lush, never experienced screetchin sound on power up that some guys report, reverb, delay and chorus are brill

have used it on average 3 times a week for the last 8 years, the best piece of kit i ever owned, on my 2nd mains transformer

i used my original dealer 4 years ago to get my replacement transformer, it took 4 days, but then i live in england

i just love its transparent yet warm sounds, i have tried all types of processors at home and on gigs, but none can compare, wish it had a tuner tho, i am on lookout for another tho just in case it should inevitably die on me

Very, very easy to program. Good fast dials. Anyone with a bit of knowledge of multi-effects or even how pedals works could get it working great first time.

I have used it with two different preamps and it works perfectly with both. With the JMP-1 it is a dream. It seems to be matched for the JMP-1 and the choruses and delays are excellent. The ability to store the mix between processed and analogue sound is very useful in retaining the inherent nature of your tone.

Never had a problem with it. Battery still at maximum 4 years down the line. Very dependable.

Not the best in the world. I lost the manual so had to buy one from the internet.

I like the fact that it does not come with a load of crappy distortions. A good amp, pre-am or your favorite stomp box should do this. It would be nicer if it had a tuner. Much easier to program than the TC G-major. Sounds are very nice, clear and lush.

Very easy to use. I purchased a JFX1 used and have never been able to lacate a manual, and yet I have been able to get everything I want out of the unit. It is very straight forward and simple. If I could find a user manual, maybe I could find a manual I could make it do more.

Clean and transparent. Very quiet. Chorus, reverb and delay sound top notch!I would like to have a unit that sounds this good with the capability of more available effects. I use it with a JMP1 through a mesa 50/50 power amp and an intellifex ltd. The intellifex is used just for the hush, to quiet the high gain jmp1 settings.

I have never had any trouble with this unit...ever. Had it for about 5 years.

I would like to have a manual for this unit. I contacted Marshall to inquire, with no reply. That disappoints me because I love Marshall Gear and own several Marshall Amps and Cabs.

I play many styles of music, primarily rock and pop. Been playing for about 25 years. I would try to find a replacement for this unit if lost, even though I only use it in the studio. I dont take my rack out mainly because it weighs a ton! If I were still using the rack live, I would definately use the Jmp1/JFX1 combination. Its AWESOME

I Found the unit very easy to use,editing patches was so simple. The manual from what i can remember was easy to understand, does anybody read them?. Never thought they could be upgraded!!

My first rack set up had Rocktron intellifex,korg rack tuner, JMP-1 pre amp and a JFX-1. The effects require a lot adjustment to obtain a useable sound. Works well with the JMP-1, but lacks something.

I had three of these JFX-1 and they have a mind of there own. On my first gig with the unit, after two songs the chorus disappeared. Not a good start!! You could only get the effects back by switching off then on again. So had that changed, Number two after setting it up 2 hours for my taste. Then at the next gig 'surprise surprise' it cut out again, two units in a row both new. Third one hand delivered to me by a marshall sales rep, The same problem as the other units, was the last straw for me. Got my money back, reliable that's a joke Mr marshall!!

Customer support, yes they were good but never got answers. Told me there was nothing wrong with the second unit i had (Factory checked) so why does it keep packing up? they did not have a clue.

Play in a social club band here in the uk, i own a Fender 'VENTURES' strat (Limited edition) a 1979 'ANTIGUA' strat. Both used on a regular basis. My music covers 60's onwards instrumentals light rock ect anything that keeps the punters happy!! The ventures strat is so good for so many style's of music, mid boost is a real toy mid solo, sustain, thick and sweet!Dont like the control knobs though, there from fenders amps, look out of place but thats life. Being made in japan was a bit off, but the sounds make up for that label. The antigua strat from 1979 is built like a british car not very well!! with the 3 bolt micro tilt neck, likes to move. The neck sockets been cut too big. Neck itself is a whole tree! very big and round. So even though it's been set up only a couple of months ago, and is as good as can be for a 70's strat, i don't play it much. My rack now is too big and heavy to move but love it just the same. A JMP-1 pre amp, Rocktron intellifex, Quadraverb 2 loaded with echoes from the past for Hank Marvin sounds,Korg rack tuner, Marshall 8008 power amp. Speakers were peavey 16ohms changed them to celestion 120H the 16ohm peaveys knocked my power down to about 60 watts a side. With the celestions i can run full power if i want. Run in stereo of course though live this can be too much if spaced more than 6 feet apart. As for the JFX glad i got my money back its crap no wonder they dont make it any more.

Very easy to use. I made a review before but it seems to have been lost in hyperspace. Let's try again for a 2ND TIME!! The features have been gone over a million times so I'll only add additional info on this. Easy to edit. It sounds quite cold and brittle. I sold mine a long time ago so I can be totally honest without feeling I bought a pig and a poke. Good manual. http://www.fortunecity.com/tinpan/radiohead/1364/
Only one version available and only made for one year aback in the mid 90's.

I am the one and only great Rockmaster so I know tone. Sure I love Peavey but that doesn't mean I don't like other gear out there. Not noisy just cold and iced up. It keeps the sound true but at the same time I feel like I'm losing tone and getting frozen. Effects are decent but not live sounding. Kind of the same thing as having a zombie sing vocals and wondering why it sounded dead. I like analog pedals and rackgear because the components generate the sound, not some program. I am my favorite artist. I am the Rockmaster.

Can't rely on it. BATTERY started going so I finally sold it at a loss. The batteries that go in are not made anymore so it becomes a nice pawnshop garbage prize. These will be littering the pawnshops from coast to cost waiting to sucker in the next sucker. "$40 for a Marshall. I remember when I played through a Marshall JCM 800. I wish I had this back then," say the Pawnshop owner. "Really is it that good," says Oxygen. "Yeah. I'll give it to ya for $40. Just don't tell anyone the good deal I gave you," says Pawnshop owner. "Sure," says Ox customer. The customer leaves..."What a sucker. That Marshall is fried and worthless. I was just gonna throw it out. Hee, Hee hee."
http://www.fortunecity.com/tinpan/radiohead/1364/
If you think I am a jerk or whatever or even crazy, email me and I'll put it on my site dude. I love Peavey and too bad for you.

Good for current stuff. Bad for other stuff. JFX-WHAT?

http://www.fortunecity.com/tinpan/radiohead/1364/ i DUNPED IT GOOD. Dimp dimp dump dump. Sold it to some loser that thinks the JMP-1 sounds good and is a tube pre-amp. Buddy. JMP-1= SOLID STATE with tube lightbulbs. Work without the tubes cause I tried. JFX-1= pawnshop dustcollector and general giver of misery. Rip-Job Ho-Bob. Battery is not made so crap. Also cold sounding compaired to modern digital units and not many features. Looks good for a coaster. If you bought this, sell it immediately before the battery starts to go. Also Marshall does not give support to thsi unit. Belongs in a pawnshop or as a doorstop into a stripclub/brothel. I am dissapointed in it so I sold it. I thought the Marshall name would be cool. Not!!

Super easy to use and very easy to get a nice sound out of it. Previous reviews have gone over its features, so I'll just tell you what I think of it.

Very nice 24 bit sound. The converters are top notch too so no signal degredation. I love it and I wouldn't use anything else. Compaires to TC Electronics' high end digital effects processors. Beats the hell out of Lexicon and is lower in price.

I bought it new old stock as I have been looking for the JFX-1 for sometime now. Their price has skyrocketed it as the JFX-1 has defined what an effects unit should be. I love it's sleek gold face. I've never had a problem with it but I have only had it eight months.

Marshall has always been good to me for info and questions. Never a problem with their gear.

If it were stolen, I'd buy it again in a heartbeat. That's how good it is. The price keeps on going up because of its great sounds and collectability factor. Marshall only made so many of these and that was it. Marshall only made it for one year and then suddenly stopped making it. Probably a limited run. I love it so much and I would never sell it 'cause I couldn't buy one again. If you see one for sale, snatch it up before someone else does!

This is about as simple as it gets. If you've had experience with any of the newer digital processors, this will take 2 seconds to figure out.

'98 PRS Standard 22 into a variety of toys that I've collected over the past couple of years, mainly an RP14d, Line6 DM-4, and a 70s model Fender Bassman. When I plugged this thing in, I couldn't believe how much better the effects sounded compared to the RP14. I'm keeping the RP14 for its decent direct recording abilities (I get some great sounds out of it), but as far as live playing its going to be "out of the loop" (no pun intended). I've got a JMP-1 in the mail, and can't wait to use the two together.

Dunno, haven't had it long enough, but I bought this thing used (VERY used, mind you) from a local guitar shop. It looks like it was sent into a warzone at one point, but seems to have come out intact. Very nice.

Never dealt with them on this subject. I've heard mixed reviews about Marshall support.

I play a lot of Brit metal & classic rock (Iron Maiden, Pink Floyd, Led Zep) as well as a little Satriani and the like. The difference in sound between my before and after this thing is astounding. I happened across this thing as a clearance item in one of the big chains, and thought, "Well, maybe it will make a good companion to the JMP-1". They didn't have a power supply for it, so I made them swear that if I didn't like it they'd take it back. THANK GOD I TOOK THE RISK. Sounds wonderful, and at just under $300 was a great alternative to dropping $600 on a MPX1 or what not (which gets very mixed reviews)

The manual is concise, and includes everything you need to know. The unit's menu's are'nt complicated, with very few settings to tweak. It's not overdone like most (actually ALL) effects units I've used. It has the 4 effects I'll ever need to have- flanger, delay, chorus, reverb.

Gretsch Electromatic (Duncan fitted)-> Marshall TSL100-> 1960A cab. The JFX-1 is extremely quiet, and does'nt degrade your guitar's original beautifull tone.

I don't have a backup unit, but I won't need one. Very dependable. I've noticed some reviewers complain about a screeching noise when they turn it on sometimes. I've never had this problem.

Never dealt with customer support.

I play hard rock/metal (think TOOL here, Alice in chains, In flames). The JFX-1 gives me all I need to tweak into my own "sound". I've been playing for 4,5 years now. I use NO other effects. If it gets stolen, I'd definitely buy another (IF available). I like everything about it, but the ONLY problem is- do someone know if you can tap in the delay time with an expression pedal of some sort??? My favourite feature is the quality of sound. You're original tone stays intact. I did compare the product with various other multi-effects models; they were all overdone and offered useless features, and they were all a bit expensive.
If there's anything else I'd add to my rig, it be another cab, and a few extra guitars :)
The JFX brings a whole new dimension to my band (www.jesuschrysler.co.za) and I wish it'd been there from the start.

This has got to be one of the easiest processors to use ever. It has been slightly overlooked here in England in favour of those all-dancing/singing units but little did those people know what they were missing. You can take it out of the box and start having fun immediately. However, should you need it, the manual is very concise and will bring your attention to a few surprises that this little beauty has.
Editing is a breeze as you've only got a couple of pages of parameters to tweak but don't be put off by that - this thing is powerful and all the control you could wish for is there!

I use this in an all Marshall rack set-up (JMP1 preamp,Valvestate 8080 power amp with 2 X Celestion Vintage 30 loaded Mesa Boogie cabs).
My main guitars are a PRS Custom 24 and a Fender Strat with 3 X Gold Lace Sensor pickups. I've been using this set-up for 5 years and the marriage of Marshall products has been fabulous. As both the JMP-1 and JFX-1 have an input knob, you have immense control over your volume and it's also a very quiet unit. You also have control over the amount of effect to direct signal - standard things on units such as these but this one actually works and seeks to retain your original tone/sound and enhance it.
I mainly use combinations of chorus, delay (various) and reverb and the quality and variety of these are great. They do not get in the way of your sound like some units (Alesis Quadraverb). Instead the sound remains both crystal and clear and you could be forgiven for thinking your using a BBE - Really, it's that good. I have been told several times that this unit was made by Marshall using Intellifex spec and components and is supposedly based on it - can anyone confirm this as to my ears it's as good?
I can emulate the sounds of many top guitarists with this (Santana, Robben Ford, Gary Moore, Rolling Stones, Brian May, Andy Summers, The Edge, Steve Lukather, Neal Schon, Pat Metheny, Stevie Ray Vaughan)
and I'm in the process of constructing a website for my settings.
The only effect I feel is missing is that of a dedicated compressor. Whilst you'll find one in the unit, it's part of a parameter for the delay. However, one of the best features this unit has to offer is the Remote Jack. If you use this unit with a non-Midi set up i.e. amp or head, employing this feature will allow you to switch channels on your amp and take along with it the particular effect setting you require - genius. Not many units offer this although I've noted that it's gradually becoming a feature on Korg pedals and TC Electronics G Series stuff. Remember, this unit was made about 8-10 years ago!

Absolutely - 5 years on and no problems. I might change the battery soon just in case but then the unit warns you about that too!
I personally don't have a back up although I've a friend with an identical set-up and so we can rely on each other if need be. He recently dropped his whole rack from about 4 feet and apart from a bent input, the unit worked perfectly.

I haven't had to deal with Marshall but other people have informed me that they are excellent and so I will not give a rating but offer the following. The above friend recently visited their repairs department and not only were staff friendly and informative, they fixed the problem, replaced other components and did a thorough check of his rack for around $50. So impressed was he by the service that he wrote to Jim Marshall and received a personal reply from him within days.

This has been one of the most musically inspiring pieces of guitar gear I have ever owned and there have been many. Other effect units I've owned in the past just get in the way and quash your tone. I have been playing for about 18 years and have many varied tastes and need to play many different styles. I currently play in a function band but I've used this in all sorts of bands from jazz to heavy rock and it works!
I would replace as it's a good unit and you can pick them up used for #150. For this sort of money, quality and flexibility (remember the remote guys)you can't go wrong.

This is one of the easiest rack processors that you will use. The manual is complete and will get you out of any problems you encounter.

I play mostly noise pop and vintage rock (50's 60's and 70's). I own many killer tube amps and several American Fender and Hamer USA guitars. For effects I use mostly fancy (i.e. expensive) boutique pedal effects.

I bought this unit about 4 years ago when I was using mostly rack stuff (JMP-1, Mesa 2/90 etc). I used to own a Rocktron Intellifex and I sold it to raise the cash to move to the Bay Area from Sacramento (this was when they were listing for $1200). When I got to the Bay area I was desperate for some effects to use with my rack amp but I didn't have a lot of cash. Guitar Center was having a big sale and was blowing the JFX-1's out for $200 each. At that price I couldn't turn it down. I'm glad I didn't. The overall sound quality was as good as, and in some cases better than the Intellifex even though it didn't have as many features. The JFX-1 has a similar internal routing as the Intellifex in that your direct signal is split so your entire signal does not go through analog to digital conversion and back again. The JFX-1 seems to have way more headroom than the Intellifex as well so your tone stays big and fat not harsh and grainey.

I no longer use rack preamps and power amps as I use mostly vintage and vintage reissue amps, but for recording or for my amps with effects loops (like my Fender Prosonic) I still find it quite useful. It will even switch amp channels with it's relay switcher.

In the 4+ years that I have owned it, I have not had a single problem with it.

Never had to deal with them about the JFX-1, but when my JMP-1 was having issues, Nick Bowcott at Korg USA took good care of me.

The JFX-1 is no longer being made, but it's a great unit and if you can find one, they're well worth it. Like I said, I bought mine new for $200 (they were about $700 or $800 list) so for me it was a great value. Unlike other rack units I have bought in the past, this one has yet to sound dated. Besides the quality of sound (which is very good) I think that's the best thing you can say about any rack effects unit.

The "NO BULLSHIT" processor!!
Thats right. Doesn't have a lot of useless effects and ton of settings for each one...gets right to the point. You got Chorus, Reverb, and Delay sounds....all you need. Since there is "NO BULLSHIT even without manual after just a few min of playing with it you can create the sounds you want. Since each effect only has a few settings it is simple to adjust your sound.

"NO BULLSHIT" such as over-processed sounds that other processors like Digitech seem to have. Reverb and Delay sound very natural. Chorus sounds very nice for clean tone as well.

There has been "NO BULLSHIT" about problems! Works fine.

Havent dealt with them yet. But im sure they would give me "NO BULLSHIT" in the event that I would need to contact them.

"NO BULLSIT" I would recommend anyone to buy the "NO BULLSHIT" JFX-1 Processor. I play Rock music but this unit is perfect for all types of music. I been playing off and on for about 7 years. This unit works great with my other rack mount units. My rack is as follows. Marshall JMP-1 Processor, Marshall 9200 Power Amp, Dual channel 15 band eq, BBE Sonic Maximizer, Alesis Compressor/Limiter/GateMarshall JCM 900 Lead 1960a 4x12 300W cab, and last but certainly not least...The "NO BULLSHIT" JFX-1 Stereo Processor by Marshall.

Rather easy to program - user friendly. The menus only nest one or two deep, so you needn't be a programmer to operate it. As mentioned on other reviews, the effects are few but well done. Chorus, Reverb, Flange and Delay. They are analog so they retain the beautiful sounds of your old analog pedals.

I use the JFX-1 with the Marshall JMP-1 preamp (the best rock preamp ever made). I have the JFX-1 in the preamp's loop and control effects patches via a midi cable - switch to a different preamp tone and it switches to the appropriate effect. I think the reverb is excellent and the chorus and flange are very good. The delay seems a little weak to me, as another reviewer claimed. Running a stereo rig unleashes the real potential of this item. Overall it provdes several very well done analog effects - the ones you are most likely to use. None of that overprocessed harmonizer/pitch shifter junk here. Just an honest working man's effetcs unit.

Had it 5 years and no problems whatsoever. I would use it on a gig without a backup, but then again effects are the icing, not the cake.

Never dealt with them. Can't say.

I do mostly rock and blues at home. I play a Les paul Standard. I use the JMP/JFX pair through a Marshall tube power amp and a Marshall 4x12 cabinet. I also use the JMP/JFX to record direct using PC mutiltrack recording software - this pair *excels* for this purpose. Overall this is the rig I have been looking for... I don't envision ever getting anyhting else unless this rig is stolen or destroyed

the buttons on the face say it all. EDIT and STORE. it has knobs!!!!! it has has a volume knob on the face, too!!!!!!!

the effects are sparse, but the quality of them is excellent. this is an effects processor for mainly guitar and NOT a guitar preamp. this is a very good thing. it also keeps the original signal analog and adds color to your tone, not mushes them together. i use it for chorus and reverb on the FX loop on my 5150's distortion and chorus, reverb, and delay when i'm clean-this is the way i play my acoustics through it, too.

i did leave it on for about 18 hours once on accident. the time after that it made my speakers pop in and out very rapidly. i promptly retired it for about a week while i made a few calls on repairs. i then tried it out before i took it in to make sure it was bad and it sounded perfect. needless to say, i saved myself some grief. since then no probs. but i am looking for the best MIDI foot controller for it. i want to buy a digitech control 8, but am wondering about the remote switch option. someone let me know something

they told me of two repair shops in "my area". unfortunately one was history and the other one was at least 60 miles away. it was also hard to reach them especially since it went out on a holiday! but after i finally reached them, i informed them i had no manual for it and they mailed me a photocopy of it to me within a week. a major plus.

i play 80's technical metal and i don't really like effects. i believe playing the guitar means you, guitar, and amp. i love my 5150, but was a little dry. i use the jfx-1 for a bit of spice and thats it. i love the fact that it was once a $900 unit and i got it for $150 and if it were stolen i would kill entire clans of people to get it back...or buy an Alesis quadraverb.

G'day Fella's, Jezmond from Australia here. Stoked to have finally found a site where someone will listen to me on about how good the JFX-1 is.
This love affair began three years ago when I stumbled accross Jessica lying in a lonely porn shop. She summoned me with her golden face and simple yet stylish display of goods, $300 later and I have been playing her like the bitch she is for more than three years, she loves it! We play awesone gigs together, travel together ,she watches me get pissed, play hard and then makes me sound better, I even think that she has contributed to me picking up other women, never ever complaint or committment query..........THE VERDICT = JFX-1 ROCKS!!!!
I agree completly with your other reviewers as to it's ease of use, sound quality and customer support. However they seemed to have forgotten to mention it's most outstanging feature.
"THE JFX-1 CAN CHANGE CHANNELS ON YOU MARSHALL HEAD!!!!!!"
Select your effects for a clean sound and heavy sound and program the JFX-1 to change head channels (easy as via midi foot controller, remote on off) PERRRRFFFECT. The only other effects unit I know that can do this is the IntelliFX which costs around three times as much.
No tranny preamps here just a beautiful dual channel JCM900 Marshall Head with glowing valves and timeless tone. I say get a head and buy a JFX-1

soooooooo gooooooooooood

Backup shmack up!
More gig's need JFX's

Never stuffed up, just call Marshall and tell em you've got a JFX and they will growl your bumhole.

For anyone you wants to know I play in an original band in Perth WA called Greenroom. We play melodic hard rock and also do a number of acoustic shows around Western Australia, the JFX is perfect for both/all occasions (even used the JFX playing fingerpicking stuff during a wedding service and then sometime later unfortunatly at a wake).
If stolen I would hunt the smelly dog and interview him around the face and balls.
I love everything about it but hate the fact that it does not have a bypass button on the face.
It helps make music as it is conducive to motivating me to play more...ah the tone mmmmmmmmmmmmmm tone.
Anything I'd like to share ? transistor amps, pissy distortion footpedals, and puffy shirt wearing widdly diddly ponces blow dog.

The JFX-1 is a really good processor for the money. It does not have very many effects, but the ones it does, it does well. It has Chorus, Delay and Reverb. I didn't get a manual with it (I bought it used), so I cannot comment on the manual. Editing patches is simple, hit "Edit", dial in the sound you want and hit "store". It's that easy.
I don't believe the unit can be upgraded.

I use this processor with a Marshall JMP-1 (in my opinion, the best preamp you can buy). My JFX-1 works perfectly, but I have heard reports of some units have a problem with creating a screeching feedback when you turn them on. Mine has never done this a single time, but who knows...
The reverb from this unit is very very nice sounding. Of course you can over do it and ruin the sound, but it sounds good if you take a little time and adjust it just how you want it. The chorus also is very good. Nice and full. The only thing that isn't 100% on the JFX-1 is the delay. Sometimes it doesn't seem to exactly reproduce what you played. It's also weak if you don't pick really hard. The delay is my only gripe about it, and also the only reason why the sound quality gets an 8 instead of 10.

I've never had a single problem with it, but like I said in the sound quality section above, there have been several reports of terrible feedback from this thing. I've never experienced that though.

Never dealt with them.

I play mostly heavy guitar type music. Along the lines of Filter, Tool, old Soundgarden. If this unit were lost or stolen, I don't know, I guess I would buy another one if I found one at a good price.
I'm sure there are processors out there that could do just as good a job and include more effects. I wish it had a better delay and maybe a few more parameters to control all the effects.

I am posting this because I have never seen a review on this product, in this forum. Nor have I ever recieved such awesome responce from so huge a company when I had TROUBLE. But I'm getting ahead of myself. If you own a Marshall JMP-1 preamp there is NO better sounding ,no easier to use, effects unit available, its designed to be used in the effects loop , Only time-based effects(chorus,delay and reverb). the direct signal STAYS analog.the best user-manual i've seen for an effects processor.

I still am amazed every time I bring up the JFX input level knob (from 0) while a chord is sustaining, just to listen to the wall of sound surround me. JMP owners, get one of these if you can!

Here's the problem, I was in SanDiego, at the GuitarCenter, when I saw this unit in the sale rack,(MAY 98),$240.00 , I remember when these units first came out,$899.00, I bought it without even trying it out! when I got home, it worked perfectly, BUT every so often, about every 10th power-up it would come on screaming! with a noise like microphonic feed-back. if you punched it on and off ,over and over it would come up quiet. needless to say this was not acceptable. assuming the unit was used, I sought to repair it myself, no dice. Tried to find someone who was familiar with the unit to repair it, also no dice. When it worked, I loved it! I wanted to get it fixed, My 30 days were up, so I could not return it to the GuitarCenter, BUT I was telling my sales person about it , when he pointed out that, this JFX was NOT used, and in fact, had never been sold,even though it was a 1995 model. He suggested that he call Marshall about a Warrenty Claim. I said "OH sure, warrenty on a unit no longer made!" He insisted, and called. (Thankyou, Jason Fleming)

Marshall said- OK! we'll warrenty it. I could not believe it! they said they would send for my unit FEDEX , and send me a good "C" unit in exchange. They did. BUT can you believe it ,the new unit looked used and came with no power adapter, and to make matters worse, it SCREAMED every time on the power-up, no matter how much I turned it on and off it still SCREAMED. I called Marshall, A great guy named Matt Maiello took my case, He told me that a "C" unit was usually a customer return, but for a dis-continued item, sometimes thats all thats available, BUT that he would see if he could come up with an "A" unit,(NOS). I said thanks! whatever you can do. He did it! they again picked up the 2nd unit, and I recieved a brand new unit , with power adapter, user manual, and warrenty card the first week in Sept. I held off from writing this to allow for problems ,but there have been NONE! I so appreciate this fantastic support, that for my daughters 14th birthday, I bought her a Marshall VS65R amp!

If you own a JMP you need a JFX! I also use a Rocktron Intellifex XL, but its designed to be used on the preamps' outputs, and thats where it is. between the 2 units , the skys the limit!