Potential New JP2C Owner

[bandit2013]

I believe the limit is with the power tubes. The function of the gain control was night and day difference when I had the 443 in the amp vs the 440, 448, or the 415.

I would have bought the Mesa branded TAD tubes as they get tested, sorted and match to Mesa spec. Even if they are off, they will fall within a given range. If you bought from TAD, I would have requested a tube with early onset of distortion. Not too early, just enough so it is not all headroom. The JP2C needs that Dumble tube distortion effect to sound proper.

The Simul-Class Marks, as I said earlier, push that push-pull section very hard, some refer to it as the Class A sockets, it is not a true Class A. It is in reality a form of Class A/B but biased closer to a Class A operation so it distorts more. In a fancy term, Mesa calls it extended Class A. The outer pair are wired like a Clas A/B much like the Roadster, just has a grid stopper resistor but it will behave in Class A/B for specific volume levels but will then drop to Class B since most of the current will be passing through the Extended Class A push-pull. Early versions had to use EL34 tubes in that extended class A circuit as the bias voltage was too low resulting in higher plate current for a 6L6 to handle. May explain the 15W from that part of the amp. Mark IV came along and they managed to alter the design that is more compliant for a 6L6 tube but yet worked great with the EL34. No bias switch required. Mark V came along, pushed of the bias voltage so it was no longer suitable for EL34 tubes unless you had a main bias switch. Same for the Mark VII. Since it has no variac/tweed power mode, not sure how long the EL34 tubes will last. They do sound really good in the Mark VII. I will have to run a comparison between the two now that I have two of them.

JP2C just 6L6, it is based on a Mark IIC+ HRG after all (assumed). It ain't no KRG, not with only 4 power tubes. Not sure what to do with 150W in a small room. Never, mind, I am running 4x100W amps at the same time. When they are all in phase, it is equivalent to pushing air with 400W. Lets just say I do not run the amps at gig level as I would if it was just one amp.

 

[bandit2013]

Sorry for adding to this. Just for S&G's I was curious how the EL34 in the Mark VII would compare to the 6L6. Grabbed a pair of the STR447 out of the closet and stuffed them in, set the bias switch and ready to go. I was planning on running the other Mark VII to see if I can hear any difference. Left the JP2C out but this was loaded with the STR415 tubes. OMG, I did not realize that would be a near perfect match for the JP2C. The STR447 have a grey bias color code. Those usually run green grey and blue. Too bad the JP2C cannot run alternates like this.

What was a pleasant surprise, it was not voiced like a nasal goose like the Mark V90 sounded like with the EL34 tubes. It was not much of a vocal change at all, perhaps some sub low frequencies shaved off a bit. The grind was just as strong and powerful as the JP2C. Will have to compare that to the Badlander and the other Mark VII eventually. What is cool about the Badlander, even though it is more focused to run EL34 tubes, Mesa did it right this time. Much like that 6L6 tone without the nasal goose characteristic getting on your nerves. Tight and percussive, plenty of low end to satisfy without swamping the field with muffled notes. I would not say it was overly compressed. So, the Mark VII is a win in that arena just like the Badlander. JP2C just is in a class all of its own. Will have to see how long those EL34 tubes hold up to that oversized power transformer. I am going off topic here.

Do let us know how you make out with the TADs.

 

[rarebitusa]

Experiment #1 complete... ran my germanium OCD directly into the effects return and plugged into the pedal. Other than it sounded muffled, there were no pops, hisses or groans.

Did I prove anything? No clue LOL!!!

So if it were me I'd be looking for the tonal comparisons. IIRC the root original problem was

"channels 2&3 are just weak"

Here's what I'd do

1) Power Section Test. Take the OCD and run it into a known amp's FX return, use the guitar/pickups that outline the original issue and get a baseline of a tone and volume level that have a "good tone". Then transfer this over to the JP2C Fx Return and set the master vol levels to basically where the baseline was. Make sure the GEQ is off. I'm not sure with the JP2C if the GEQ is before or after the FX Loop. Go back & forth between 60/100 also. If this reveals very little ie: they kinda sound similiar, nothing is "thin or weak" I'd say the problem is in the preamp.

2) Preamp Test. Guitar->JP2C amp in-> FX send -> FX In of your baseline amp at the volume settings you had in the power section test. Cabs on both. Now start playing with settings. Start with the GEQs off. For sure try the sample settings outlined in the manual. Just to see if there is any progress with the original issue.

BTW, those are really nice Suhrs

 

[ntotoro]

So if it were me I'd be looking for the tonal comparisons. IIRC the root original problem was

"channels 2&3 are just weak"

Here's what I'd do

1) Power Section Test. Take the OCD and run it into a known amp's FX return, use the guitar/pickups that outline the original issue and get a baseline of a tone and volume level that have a "good tone". Then transfer this over to the JP2C Fx Return and set the master vol levels to basically where the baseline was. Make sure the GEQ is off. I'm not sure with the JP2C if the GEQ is before or after the FX Loop. Go back & forth between 60/100 also. If this reveals very little ie: they kinda sound similiar, nothing is "thin or weak" I'd say the problem is in the preamp.

2) Preamp Test. Guitar->JP2C amp in-> FX send -> FX In of your baseline amp at the volume settings you had in the power section test. Cabs on both. Now start playing with settings. Start with the GEQs off. For sure try the sample settings outlined in the manual. Just to see if there is any progress with the original issue.

BTW, those are really nice Suhrs

Thanks!!! Those are my two favorites. I need to take pics of the others. The GEQ must come after the effects loop, since it did affect (heh... ) my sound. I was able to tweak it in my experiment. I do need to test the preamp section through another amp. I was a little discouraged with the OCD into the effects return, since it seemed to me that showed it wasn't the power section. I mean... I don't know if it was scientifically valid, but it seemed logical. The master volume on the channel I had selected (channel 2, in this case) did operate as a master volume. There was still some hiss that didn't seem gain-related, though, so...

Using the pedal in the effects return did not sound weak at all. Sounded like a totally different amp. That's the reason I felt discouraged.

@bandit2013

Thanks!!! Those are actually ziricote boards. I got that inspiration off an acoustic guitar I have with that as the fingerboard. Love the way it looks. My Modern T has the same. Are you saying the new Charvels play as well as your Carvins? Have you noticed a change in QC between Carvin & Kiesel? I do dig those 7's you have! Man... I remember those Carvins with all the pole pieces and the Craig Chaquico ads LOL!!! The issue I had with the original Stiletto was that it did sound thinner than I liked. There felt like there was nothing behind the notes and it wasn't the stringy, kind of cool Plexi thing. It was just thinner for the sake of being thinner, slap in some EL34's and say it's Marshally. It really wasn't. Took me yeeaaaaaarsssss to realize the high-gain Plexi thing wasn't what I wanted after all.

How close do the notes with the Badlander come to the JP2C? I know... buy nice or buy twice... just curious LOL!!!

...or maybe I'll just get a Badlander 50 as a sibling... or maybe a 100, since they're the same price now LOL!!!

 

[rarebitusa]

I was a little discouraged with the OCD into the effects return, since it seemed to me that showed it wasn't the power section. I mean... I don't know if it was scientifically valid, but it seemed logical. The master volume on the channel I had selected (channel 2, in this case) did operate as a master volume. There was still some hiss that didn't seem gain-related, though, so...

No I wouldn't be discouraged you have reduced the scope of the problem!!! Now comes the fun part. Since Ch2/3 are identical it's probably the same internal signal path used for both but the just switch for different GEQ, TMB, Gain controls. Interested in the outcome.

The Badlander IMHO is a great amp.

 

[ntotoro]

No I wouldn't be discouraged you have reduced the scope of the problem!!! Now comes the fun part. Since Ch2/3 are identical it's probably the same internal signal path used for both but the just switch for different GEQ, TMB, Gain controls. Interested in the outcome.

The Badlander IMHO is a great amp.

I may have to get one of those, too! Same cost, but is there a bit tonal difference between the 50 and 100 models? I know that's off-topic.

The power tubes will be here Tuesday. Crazy thing would be if they actually made a difference after my experiment made it seem like they weren't the problem LOL!

 

[bandit2013]

I have no issues with my JP2C, and found there was a point with the gain, about 9:30am and 10am where the change in rotation above that point had little or not effect. That was the oddest thing. It seemed to only be related to the STR443 tubes in the amp. Go figure. Not sure if it is the phase inverter not properly driving the power tubes, or something else. I literally believed I had a preamp tube issue. Freaky thing. Swap the STR443 with some older STR440 and all was back to normal.

I wanted to try those STR443 in a different amp, but one that was close to its design, Mark VII. Not really all that close but as close as it gets. I did not experience the same effect of lack of gain range. It had some form of adjustment range, 9am is where it cuts out, one I got the gain up to noon, it was pure mud-fest. Grey bias colors too much for the Simul-Class and it was not very usable.

The fact that I was able to experience the lack of gain adjustment with the same power tube is hope that the issue is more or less related to the tube and not the amp. That was sort of freaky to discover that phenomenon. I never really noticed it before when I tried them, just thought they sounded blah.

 

[ntotoro]

The really funny thing would be if my replacement preamp tubes turned out to be bad LOL! We'll definitely know more Tuesday.

Do the power amp sections of the various Mesas behave similarly in regards to their relationships with the preamps?

 

[bandit2013]

Carvin vs Kiesel, good question. I am sure there was a departure in terms of the customer support. I do recall many complaining about that on the Carvin board. I do not go there anymore. As for workmanship and quality, It has improved. Every Carin I have ordered or adopted are of quality workmanship and materials. Generally it sort of does fall on the customer for selecting features that probably should not have been chosen. You can select fretboard materials, fret wire, fretboard radius, neck profile, body woods, chamber or not. Head stock shape, you name it. All was fair game. It was the model you selected to build that determined if it was neck through, set neck or bolt on. The last Carvin I ordered is actually a Kiesel guitar but they had the option for the choice of logo at that time. I chose Carvin as the Kiesel logo was not offered in gold. That instrument is top quality all the way. It was the business model that changed after Jeff Kiesel took over the business from his father. Before it was a good place to find parts for the instruments, including necks if you want that sort of thing. It was a luthier's place to find neck though stuff and build your own thing if you had the capabilities. All of the parts were available. Now that business model has changed to guitar only. No parts, no support and much higher prices. They also dropped the Floyd Rose which is what I wanted on my next axe but only specific models had that option. So, I moved on to Charvel and that was that. Not the same quality of materials. You get to choose what is available and not do anything custom. They do have a custom shop but no way to order such that I am aware of. I do not feel like spending $6K to $10k on a single instrument. I would rather buy a few amps and do something nuts like running a full stereo in quad mode.

So yes, the Charvel guitars have a good feel to them. From the San Dimas, So-Cal and DK24 they all have the same feel and comfort. Very similar neck profile as my Carvin/Kiesel guitars. Just not as expensive in the exotic wood department, more of a show thing without being a slab of wood. I like the FR bridge and only go after those with that installed. Fretwire is only nickel silver but at least they are using graphite reinforcement in the neck which does add stability. All bolt on guitars. The old parent brand Jackson is now a sister brand owned by Fender. They have the neck through but made in China or Korea. the USA made models are bolt on necks. Bummer. I do not mind bolt on necks all that much as you can adjust the neck angle with shims. Can't do that with a neck through or set neck. I found that trick works great for that minor adjustment if needed.

 

[bandit2013]

How close do the notes with the Badlander come to the JP2C? I know... buy nice or buy twice... just curious LOL!!!

...or maybe I'll just get a Badlander 50 as a sibling... or maybe a 100, since they're the same price now LOL!!!

All the notes sound the same to me. LOL. Lets just say you dial in the controls to noon across the board on both amps. Sure, this is not always going to be the same thing. In terms of gain characteristics and structure, the JP2C is a bit more sinister and the BAD is close not balanced. It does not require a GEQ like the mark style amp and there is no trimming of midrange which is to be done using the GEQ. In my opinion, Marks sound terrible and have too much midrange saturation and the GEQ is very helpful in shaping the tone to desired effect. Note that the JP2C has the full tone stack at the front end so it is pre-gain and the GEQ is post gain. Badlander does have the basic core of the JP2C, that Mark style lead drive circuit. However, the tone stack is not pre-gain, it is post gain and driven by a DC coupled cathode follower circuit similar to a Marshall or Rectifier amp. The BAD just sounds great and is very difficult to make it sound like . No compromise with the tone controls, push the gain all the way and leave the bass where it is. I do not have to adjust that. Marks, when the gain goes up, the bass must come down or it will get muddy. JP2C tone density, just a way to describe this thick overture of sound, call it juicy or heavy. It has an abundance of character and not sounding thin or lacking. Full bodied may be it. I can't explain it that would make sense. That seems to be unique with the JP2C but it does matter what power tubes you have pushing the cones into submission. Mark VII on the other hand does not have that tone density. It is a bit of a thinner character but not by that much. Sound is very on par, just the difference in robustness I suppose. The Badlander is much the same as the Mark VII. Not as heavy but still excellent in characteristics. Note definition or clarity: JP2C and Badlander have that similar characteristic to them. The Mark VII falls a little short but can be improved with tubes having more headroom (Simul-Class has more power tube distortion). Depending on the gain setting on the bad, crush is basically the IIC mode at low gain, and slides into a Mark IV mode at higher gain settings. That covers most of CH2 and CH3 of the JP2C. Crunch is more relaxed recto like tone. It is like a middle or medium gain setting on CH2 of the JP. Not as saturated. (It will be more convincing in variac power mode as it takes more of a Recto tone with the reduced power). Drive the gain up on the crunch and things change into more of a Markish tone. The Mark VII has two modes, they are essentially the same circuit, crunch and VII is the crush mode. They are different in characteristics since the Mark VII does not use that tone stack driver circuit the Badlander has. Similar but not exactly duplicated. I actually like the Badlander for what it is. You can dial it in at 100W with a low volume setting, boost the gain and behold an awesome masterpiece of saturated sound without requiring any ear plugs. Sure, it can also be loud as hell too. Much louder than the JP2C so it runs up there with the MWDR in terms of stage volume. I have yet to find that point where it gets into mass compression. I like my hearing so I have not explored that deep. Marks, on the other hand have a limit (ok this goes back to the Mark III or Mark IV) were you can set the volume and you are at max very early on the control. After the number 4 it just gets more compressed and no louder. I believe I had the JP2C up to 2pm before noticing any compression effect. Noon is loud enough. That setting is equivalent to the 10am setting on the Mark VII. Actually I run it much lower, more at 9am. Same with the Badlander. Sorry, If I am referencing other amps that you may or may not be familiar with. Not sure how to say it. At least the JP2C is not at maximum volume at 10am. (that would be about where the #4 on the dial of the Mark III or Mark IVB would be). Different taper on the volume pot and the range is also different and more usable.

Feel: Do you feel connected, is it laid back or to forward. Bad is middle stage, you feel connected to it. It does not sit back or behind in the response or seem like it is playing the notes before you strike as that would have a forward characteristic. It is Neutral in that aspect so getting lost in what you are playing and allowing you to focus more on expression and such is really good. JP2C, yeah it has that too. Mark VII, depends on the chosen mode. It can fall back a bit or push into forwardness. Still trying to figure it out and get a food feel. I really like it. Badlander is just too easy to bond with. Any of the three modes, from clean, crunch and crush. Yeah there are three modes of gain as clean can be pushed into decent grind of sorts with the gain control.

Tone controls do behave similarly with the BAD and JP. However, some of the tricks you can do with the Mark design is not quite evident in the BAD since the tone stack is post gain. Setting the gain all the way, treble all the way and dropping midrange and bass will not work with the Badlander since the tone stack acts more like a 3 band parametric EQ and not some tailored tone to push the lead drive circuit.

I would recommend taking time to find one at a GC or other type of store and try it out in person. It is very easy to dial in so it is unlike the other Mesa amps you need to understand the relationship, what the gain does and how that influences tone, etc. It is more direct and you can literally set it with you eyes and it basically does what you expect it too. Sure, hearing it and adjusting the controls is usually recommended. Just note that the channel master will be suitable at 9am, almost gig level but not quite. Some say the BAD50 sounds better than the BAD100. I did get someone to admit the 50W setting on the 100W is much the same as the BAD50. I chose the 100W version as I get the 50W and 25W setting, bigger transformers and such. Actually the BAD50 basically has the same sized transformers based on images. Perhaps they are smaller. I just did not want a repeat of the TC50 VS TC100. Still both are great amps but one is weak sauce in tone density vs the other. longer story better served later.

 

[rarebitusa]

It does not require a GEQ like the mark style amp

So after months of discussion with @bandit2013 WRT the TC, RA100 and the Badlander. I finally relented and got a BAD 50W and I really, really dig the amp. It is so effortless to play. His take is also pretty right on with it.

However I do differ with him a bit on the GEQ topic. Does a BAD require one??? well no... but does it benefit from one... oh F yeah. It becomes a much, more flexible beast. The GEQ (in the loop) is a powerful tone shaping tool. TBH for me I always run one it's a necessary part on my config.

 

[bandit2013]

I really like how bad the BAD is. It is easy to make the BAD sound bad, but much harder to make it sound terrible. bad meaning good. It has a very pleasing grind to it. Not as thick or sinister as the JP2C but on par in some ways. Plenty of distortion on tap that does not get so rude it sucks. That is my experience with all Mesa amps except for one. The one I would call Lemon ICE. I suppose 2012 was a bad year for that one as I am not the only one who has that issue. Even the TC series can get into the ICE with. Yeah, the BAD can get icy if you dial everything back and boost only the treble presence and gain. That is what the guitar player kept doing, I had to get off the drum throne every time, and readjust it. He is sort of tone deaf and cannot hear the higher frequencies. I am quite the opposite, I am sensitive to the upper range of frequencies and have issue with the sub frequencies such that I need to use a tuner to tune the bass, 4 string is not all that bad but the 5 string I will struggle with the low B. I have not had the 5 string out in a while. Seems that the bass player will be traveling in this week. I doubt I will be able to coax him to grab the 5. Not sure if the new kid will be able to make it. I just realized a good name for our group: Dementia, but fear that name is already taken. I know what they would say on that if I mentioned it. Typical two word phrase that starts with the letter F and ends in U. That is ok, I get that all the time. The guitar player always gives me the middle finger if I see him in the hall. So much for the side talk.

One more day and we shall see. . .

 

[ntotoro]

Ok... now you guys have me thinking I need a BAD 50, too, just because LOL!!! Tough choice, since the 50 and the 100 are the same price new now. I assume it's the typical difference between 50's and 100's... ? 100's maybe more punchy, 50 maybe smoother... ?

The only thing that tuned me out of the Jeff Kiesel thing was his dudebro attitude, like he could be someone I'd see over the border in WV high on meth LOL! I'm sure the guitars aren't that at all. SS frets are the one thing in the last 30-35 years that made me say "Wow, where has this been?!?!" Smooth, doesn't require polishing and truly lets me know that it's my strings that are the problem LOL!!! The coolest thing about Fender Borg-ing Jackson and Charvel is that they can now use the headstock designs. Well... that and the HUGE variety of neck dimensions at their disposal. That EVH neck profile is a real guilty pleasure to me, but I admit it does fatigue my hands a bit.

Maybe I'll just get a BAD 25...

Got the delivery notice for the tubes, so we'll definitely see tomorrow! I got excited and thought it was today at first and got moved up a day...

 

[rarebitusa]

Maybe I'll just get a BAD 25...

Nooooooo. I'm not one to dissuade anyway but from your posts I think you'd perhaps be disappointed with the el84s. With a LSS or even a Mark 25/35 they are good but IMHO the BAD derives alot of it's tone from the el34 power tubes. Have tried 6L6s in it which actually were fine, but went back.

While I don't have a 100 to compare... the BAD 50 is most excellent. In fact I prefer tonally the 20W mode. The triode wiring is smoother to my ears and a bit looser, but I'm not a serious chunker. The 50W mode is certainly more immediate and there's a bit more headroom and feel it's nicely suited for the clean voicing and pedals. However if you crank the vol up it seems to even out. For single note work the triode mode works. Of course YMMV

While I would love to have a JP2C, only have a IIC+ HR to contrast the BAD with. They are very, very different amps. Definitely worthwhile to have both.

 

[ntotoro]

Ok, no 25 LOL!!!

Usually I'd be all about 50 watters, but both being the same price new makes it a challenge. That said, a BAD 50 would be a cool sibling to the JP2C.

 

[ntotoro]

So... the tubes did arrive today LOL!

The TAD is a little taller. No issues getting them in. Got them in, let them warm up... absolutely ZERO difference LOL! Still thin, still harsh (like a guitar with an OD direct), still hissy and poppy.

Should I even bother actually getting new preamp tubes?

 

[bandit2013]

Hissy and poppy, that would be from the quality of the preamp tubes. Sort of wonder what the TAD tubes at 33mA would compare to the grey bias color version of the Mesa branded type. Probably why I stick with the Mesa branded options. Not saying that is the case here. I would ask the vendor you got the tubes from regarding the spec used for the tubes. Tell them you needed something in the line of what Mesa uses as the gray bias color. (early distortion characteristic but with some headroom). I honestly do not have a clue what that plate current would be so I am of no help. I am almost thinking this JP is a sour grape. Not to eat it, spit it out and pick another.

I still have the stock Mesa branded JJ ECC83 tubes in the JP. I have tried others like the Mullard, Tung Sol and the like, but they had some ill effects (motor boating). There is one preamp tube that I do like a lot. the JJ E83CC tubes. I have not gotten around to getting those in the JP2C but have installed them in the Mark VII. No more noise floor and they sound great. Will see if I can find the time tonight to give that a shot. Have to set up the studio for tomorrow as it is a Jam night. Anytime you get tubes, make sure they are marked properly. As I stated before, the first set of tubes they sent were E88CC. It was almost hard to make out and I first thought they were E83CC. Not the same tube and much, much lower gain. Glad I did not make the mistake and use them. Since I have many amps, I also have a tube tester to I can see if they are ok for use. Never can tell if any damage occurred during shipping. My mail courier may as well be named Ace Ventura.

Here is a reference in case you never saw it.



Have you tried contacting Mesa Customer service? I would email them and state the issue. Gain controls have no effect on CH2 or CH3 on the JP2C. What could be the issue? (describe what you are hearing as you adjust the gain controls).

It is could be a preamp tube, but doubt it. No point in throwing money at it if there is no change in characteristics. Does the volume change as you raise up the gain? If it stays the same, with little or no change, something is up with that. I got that effect when I had the STR443 tubes in the amp. I should try the STR448 in the reds or yellow bias colors and see what happens. I have them on hand.

 

[ntotoro]

The thing that gets me... the nine preamp tubes I've rolled (I didn't touch the PI), they can't all be bad. The fact that I heard ZERO difference, regardless what I did, which tube or where, leads me to believe it's internal. That said, I still want one LOL!!! There's too much good in it. The volume doesn't change as I raise the gain, but the volume controls themselves do work.

Picture this... you're in an OD pedal plugged direct into a board. That's what this sounds like. The gain doesn't change much past noon-one o'clock, but it does change. The pull does go up "one," basically. The preamp tone controls do work and make a difference. The GEQ does work and make a difference, it just sounds like you're direct into a board.

 

[rarebitusa]

The thing that gets me... the nine preamp tubes I've rolled (I didn't touch the PI), they can't all be bad. The fact that I heard ZERO difference, regardless what I did, which tube or where, leads me to believe it's internal. That said, I still want one LOL!!! There's too much good in it. The volume doesn't change as I raise the gain, but the volume controls themselves do work.

Picture this... you're in an OD pedal plugged direct into a board. That's what this sounds like. The gain doesn't change much past noon-one o'clock, but it does change. The pull does go up "one," basically. The preamp tone controls do work and make a difference. The GEQ does work and make a difference, it just sounds like you're direct into a board.

Hmm did you get a chance to try the Mesa settings from the manual? I wouldn't evaluate them as a tone you'd like.... but more if you are hearing differences between them. Is the amp responding to them.

 

[ntotoro]

Hmm did you get a chance to try the Mesa settings from the manual? I wouldn't evaluate them as a tone you'd like.... but more if you are hearing differences between them. Is the amp responding to them.

That was actually where I started as a default...