Fender Jazzmaster Ultralight

**jorgemg1984** · 09-02-2012, 07:57 PM

Well one of the mods was actually a repair: new electrolytical caps and moving some wire because the amp had become noisy. If you have no noise you don't need this

The other two were for tonal reasons. Upgrading the op-amps it's something I did on all ss amps I had; my tech always has OPA2134 in stock and most of the times he just charges me the price of the op-amps plus a symbolic price for his time so it ends up being quite cheap. It's not exactly a huge difference but it does improve fidelity a lot compared with the TL072 that come stock. The other mod was recommended by a forum member in order to improve the volume knob; stock the volume knob basically worked between 1 and 4 and added some high end; now it's linear from 1 to 10 and does not add or cuts highs or lows. Here's the tread

Clean Boost vs Amp's Volume

It's basically changing the value of C33. I can give you the exact value I think.

As to if they are worth it... tough to say. I am lucky to have a tech that is a very good friend and makes me great prices. The OPAs increased fidelity and the volume knob mod was very important because I gig quite a lot with this amp. But it's always a risk to mess with an amp and if you're happy with it stock... just leave it!

I tend to be a little picky about details but again jazz is about details isn't it?

**lpdeluxe** · 09-04-2012, 12:29 PM

I was an early adopter and ordered one from the local Fender dealer. At the time I was downsizing and replacing my behemoths with smaller gear. I was delighted with the light weight and small size of the JMUL and even happier when I A/B'd it with a friend's '67 Super Reverb, which had been my favorite amp of all time.

I plug my 335 into it, and when friends come by it is usually the amp of choice, whatever guitar they are playing. Mine's not for sale.

**Wildcat** · 09-25-2012, 09:41 AM

Originally Posted by jorgemg1984

Really glad it's worked out for you! If fender had done a better R & D they would have launched a much better product and they could have done it as a head / cab and combo configuration like this one:

Raezer's Edge - About the Stealth 10

(amongst many other things that could have been done better; still a great amp!)

I have been running the one I picked up several weeks ago through its paces. My thought was this is an atypical design for Fender and their produce line. This amp is so out of character as Fender does many of the same things redone over and over. I heard that a lot of dealers had no idea how to sell it or promote it which made me think that someone outside of Fender came up with the design and got Fender to buy into it. IMO This amp is way outside of the box of thinking for Fender products.

**rpguitar** · 09-25-2012, 10:04 AM

Wildcat, how should "atypical," "out of character," and "outside of the box" be interpreted by those of us who love Fender's classic products? Those are very ambiguous phrases, since they could either mean it's insanely great or really awful, depending on one's impressions of Fender amps.

**Klatu** · 09-25-2012, 10:09 AM

I think that Fender wanted to cash in on some of the success that Acoustic Image was having with their Clarus line of amps. At the time The AI Clarus was released, it was marketed as a tiny amp that was the size of a cigar box and only weighed 5 pounds. I remember Raezor's Edge selling cabinets that had space to dock an AI Clarus, but they weren't such big sellers.

It's curious that both Fender and Henriksen went after the tiny amp head market, and both ended up pulling their heads from the catalogs after a few years.

**jorgemg1984** · 09-25-2012, 10:10 AM

I agree it's different from what Fender puts out. But let's say:

1) just the clean channel (smaller and lighter)

2) an excellent digital reverb instead of 10 average effects

3) named it the Ultralight and promote is a "fender tone in a small box" instead of a "jazz amp"

4) maximum power at 4 ohms and not 2 ohms so it could be optimized with most cabs (4 and 8 ohms). Specifically stating it could be used at 4 and 8 ohms

5) jack speaker connection added (as Henriksen does, speakon and jack)

6) Maybe releasing more cab options that would reflect Fender various designs 1x12, 2x12, 2x10, 1x15 etc.. maybe some open-back.

7) ability to dock the head in the speaker cab and make it a combo

8) priced around 800 (I guess savings on the OD channel could allow this)

I think it would have killed to tell you the truth...

**jorgemg1984** · 09-25-2012, 10:14 AM

Originally Posted by Klatu

I think that Fender wanted to cash in on some of the success that Acoustic Image was having with their Clarus line of amps. At the time The AI Clarus was released, it was marketed as a tiny amp that was the size of a cigar box and only weighed 5 pounds. I remember Raezor's Edge selling cabinets that had space to dock an AI Clarus, but they weren't such big sellers.

It's curious that both Fender and Henriksen went after the tiny amp head market, and both ended up pulling their heads from the catalogs after a few years.

True. But they did several erros on the product develpment still.

Fender dropped it for sales reasons I believe; in such a big company if you don't sell above X in the first year I guess you're over.

Henriksen I've heard they had some technical problems and maybe they didn't sell enough heads that justified the bother.

Funny enough I have both heads and I am completely converted to an head / cab system.

**lpdeluxe** · 09-25-2012, 10:39 AM

The JMUL was developed along with a similar amp aimed at acoustic guitar players. I consider the Jazzmaster to be really well thought out within its limitations. It certainly has features that are not typical of Fender, but it's well turned out. A friend has a '67 SF Super Reverb that I consider the best sounding amp I have ever heard. Right after I got the little one we A/B'd them with my Les Paul and we were able to get the JM to sound very similar to the SR...but with much less weight. For what it's worth, the Super uses a 2 ohm speaker load also.

I like the fact that I can dial in a sound and maintain it at all volume levels. I also like the docking of the head and the Speakon connectors. I set mine on a small stand for gigs and it's as convenient for knob turning as any other amp I have (I have this one and three Fender tube amps, by the way).

Fender seems to have misread the market, and obviously did not aggressively market it. That may mean that, if you have one, hang on to it, as Fender is not likely to bring it back. I think it is a great alternate amplifier to all the tweed-covered and retro tube devices that Fender makes, but the company certainly seems to be thriving without my help.

It's easy to second-guess Fender's design goals, but this is an extremely portable, lightweight amp that takes up very little room on stage and has a great sound. I hope mine lasts forever.

**Wildcat** · 09-25-2012, 10:50 AM

Originally Posted by rpguitar

Wildcat, how should "atypical," "out of character," and "outside of the box" be interpreted by those of us who love Fender's classic products? Those are very ambiguous phrases, since they could either mean it's insanely great or really awful, depending on one's impressions of Fender amps.

I am not questioning Fender amps are the standard or bench mark for clean tube amps or amps that can break up a certain volumes.

The Fender Jazzmaster Ultralight Amp is really something different IMO. A higher end 2 channel Solid State Amp 2 with 2 ohm Jensen Neos closed back that all weights 25lbs. (I owned a Fender 1976 twin at one time.) BTW the gain channel is the real deal here which was a pleasant suprize.

I really didn't have an appreciation for this amp until I got one which was based on the discussions on this website.

**fws6** · 11-28-2012, 06:24 PM

... but the thing is soooo loud

Based on recommentations innseveral threads in the last months I followed everyones advise and got a Jazzmaster Ultralight head. And because I wanted a versatile cab I went with the RE twin 8.

I must say I really like the sound - as everyone described it works much better with acoustic archtops / floating pus than my tube amp does. All settings to neutral and immediately a useful sound. Warm yet clear.

But it is so loud I can barely touch the volume knob and it is already way too loud to practice or record at home. my study room is adjacent to the living room. although I could dial the volume on my tube amp up and play with the volume a bit, I really have no control with the volume knob on the jmul. as soon as a touch it ever so slightly it immediately is too loud and i get complaints from the family

Soooo...how to solve..... (and yes, I am keeping the family)

**rpguitar** · 11-28-2012, 06:42 PM

I agree. And I use the JMUL with the Fender 2 ohm cab, which should be even louder than an 8 ohm RE. All of the controls are really "hot." Not just the volume, but the tone controls, too. It's one of those amps where you worry about knobs getting moved accidentally for fear of never achieving the same setting twice. Other than that, I do like the amp. Although it's far more exaggerated in some frequencies compared to my AI Clarus.

**jorgemg1984** · 11-28-2012, 09:52 PM

The amp's volume knob has two problems: works 90% untill 4 and adds highs. I solved both with a mod, highly recommended. The mod is putting a 4.7uF value on C33.

Good luck!

**lpdeluxe** · 11-28-2012, 10:18 PM

Does your guitar not have a volume control? With my 335, it's easy to keep the JMUL quiet. There are in-line volume knobs available.

**rpguitar** · 11-28-2012, 11:10 PM

Actually, I do have one guitar that does not have a volume knob. Can you imagine?? So much for that.

**Jabberwocky** · 11-29-2012, 12:25 AM

Originally Posted by rpguitar

Actually, I do have one guitar that does not have a volume knob. Can you imagine?? So much for that.

That's the way of the Purist. Straight wire with gain.

**fws6** · 11-29-2012, 03:42 AM

Jorge do you have some pics or more explanation

I am not totally technically challenged, do wiring on guitars etc all the time. I have never worked on amps though

Or actually I should say I worked on amps only once. Twenty years ago I had a Guild RT98 amp that I tried to resolder a loose contact. I got a huge electrical shock the thing almost killed me. Little did I know that also an unplugged amp can still do tyhat. So I decided to stay away from amps since then. With this solid state though I think it would be safe to try, right ?

**jorgemg1984** · 11-29-2012, 07:47 AM

Originally Posted by fws6

Jorge do you have some pics or more explanation

I am not totally technically challenged, do wiring on guitars etc all the time. I have never worked on amps though

Or actually I should say I worked on amps only once. Twenty years ago I had a Guild RT98 amp that I tried to resolder a loose contact. I got a huge electrical shock the thing almost killed me. Little did I know that also an unplugged amp can still do tyhat. So I decided to stay away from amps since then. With this solid state though I think it would be safe to try, right ?

I did not perform or even thought of the mod. The mod was suggested by a forum member who has been kind enough to help me with my tone quest. My tech performed the mod... I am the worst person on earth to perform hand-related tasks, they are only good for the guitar really

Someone already posted the schematic. It's just really replacing the C33 cap with that value... I think it's better to go with a high voltage cap.

You should not perform any mod on an amp if you're not sure how to do it... it can kill you! I think anyone who understands a little about electronics, since you have the schematic, should be able to perform it easily. I can assure you it will solve your problem!

PS - I also upgraded the TL072 op amps on the clean channel with OPA2134, very nice mod too but more expensive and harder to perform because the stock op-amps are not on sockets.

**fws6** · 11-29-2012, 10:58 AM

And you're sure it is C33 ? From the schematic I'd say it would be C30 , and C33 would be in the treble tone circuit ?

**jorgemg1984** · 11-29-2012, 11:11 AM

I can't read schematics. I just went trough all the talk with the forum member and my tech and it is C33. He explained it to me but I am afraid to post it because it was using private messages.

Send him a message, he's been REALLY helpful. I hope he doesn't mind me posting it here.

The Jazz Guitar Forum - View Profile: Insufferable_Rhythm

But I can assure it's C33, it's that cap value and it works.

**jorgemg1984** · 11-29-2012, 11:13 AM

Originally Posted by Greaser

That's interesting. I've changed op-amps in pedals before, but never heard of changing them in amps. What kind of change did it make to the overall sound?

I am a sucker for OPA2134. Use it in all my eq pedals and upgraded it in several amps so far. The one I noticed the biggest difference was the Henriksen (and some pedals). For cleans it's an unbeatable op-amp...

It is not a day and night kind of thing. The voicing / charachter of the amps will not change but I noticed much increased fidelity... It's like the same amp but better. I am being clear?

**fws6** · 11-29-2012, 11:26 AM

Okay I sent a PM to Insufferable_Rhythm hopes he chimes in

**Greaser** · 11-29-2012, 12:25 PM

Originally Posted by jorgemg1984

I am a sucker for OPA2134. Use it in all my eq pedals and upgraded it in several amps so far. The one I noticed the biggest difference was the Henriksen (and some pedals). For cleans it's an unbeatable op-amp...

It is not a day and night kind of thing. The voicing / charachter of the amps will not change but I noticed much increased fidelity... It's like the same amp but better. I am being clear?

Yeah, I understand what you're saying. Like I said, I've put different op-amps in pedals before. It's sort of like playing with different tubes in a tube amp...it can make a noticeable difference in tone, but it doesn't turn it into a different amplifier.

**rpguitar** · 11-29-2012, 04:49 PM

Volume on the guitar is not the same as volume on the amp. It cuts treble and changes the guitar's dynamic response. I use my guitar's volume knob more as a tone control than a volume control. For overall volume adjustments, I expect to use my amp most of the time.

**garryrenfro** · 11-29-2012, 11:01 PM

If at minimum your JMULs are too loud to practice and record with, my old ears must be worn more than I thought, or my amp is quieter. My studio room is far from acoustically ideal, being long and narrow, but I still find what I consider usable practice and recording volume up to 8-9 o'clock, with a humbucker equipped guitar at full volume. At this amp setting, decreasing the guitar volume allows even quieter playing to a point, but not always with the dynamics I desire.
I generally practice with the volume around 11'oclock, and I have a nice range to use the guitar volume control.
Of course, I may be playing louder than I realize. The kids have long since moved out, and in any event the garage space is between my studio and the living space, there are no neighbors close by, so I am never concerned about being too loud. Just gotta be careful not to inflict much more damage on myself.

**fws6** · 11-30-2012, 03:46 AM

Yes mine certainly is. With the volume at zero of course there is silent, with the volume past 1 it is already way too loud for home use. I simply have no room to wiggle the knob to something useful

Like Jorge said, IR responded to my PM so I will give the cap change a try