Marshall JVM410HJS - real amp versus Axe3

As well as feeling like the HJS model was dark sounding, I’ve always felt the same about the regular JVM. It’s typically an amp I think of as quite bright and almost twangy, and to get those kind of tones always took some work.

The recent Bogren plugin immediately reminded me of the JVM tones I’m familiar with, so I thought I’d try and dive in a bit closer on the Fractal model.


First the real amp tone. Very typical settings for this amp, you can basically just tweak slightly from 12 o clock and you’ll get something quite nicely balanced.

View attachment 43626

Amp Tone: https://samply.app/p/yXEcY9wp5olKpcUtvXry

My first AxeFX tone was eyeballing settings, trying to be as generous as I can to match the tone. If you put settings like this in, it sounds bloated and farty and not like how you'd expect a JVM. Even taking tolerances into account, it’s quite far off.

JVM Fractal 1: https://samply.app/p/H2fL7vtcjV40mSoFVLYM

Just to prove the tonal difference is beyond pot tolerances and tapers, the next tone sets the presence and treble to both to 10. This ends up sounding a lot closer to the JVM at "typical" settings. But this is already at the limit of what you can do with the tone now, and it just about covers “typical” JVM tones (check where the relative presence knob values are).

JVM Fractal 2: https://samply.app/p/ZN11CW4zVRNoot8YkTVF

Lastly, I did a tone that I just dialled totally by ear. This involved being more heavy handed with the amp EQ, changing the preamp LPF, changing the MV bright cap etc. It's not exact, but it's possible to get in the ballpark. But to get it to sound like a "typical" JVM, you need to get your hands dirty, AND use more extreme settings. I don't really associate the JVM as the kind of amp that needs weird settings or a lot of work to sound good, most people seem to use roughly the same kinds of settings.

JVM Fractal 3: https://samply.app/p/UoOW5WnNljRLE5C3KeHx

Eyeballing settings:

View attachment 43627

Treble+ Presence on 10:

View attachment 43628

Tweaking by ear (TOTALLY different mids, treble, presence settings as well as other deeper tweaks):

View attachment 43629

I've always felt the JVM models didn't really represent my experiences with the amps, particularly for sounding too dark/muffled. I can get close enough to be happy with some tweaks, but this only really works when having the real amp to reference against. I'd WAY prefer to be able to just dial the amp like the real thing and get typical tones with more ease.

The real JVM is an amp I think of as fairly bright/tight/twangy/aggressive. The Fractal model leans more fat/fuzzzy/dark/bloated unless you massage it into something else. It doesn't really remind me of a JVM unless you do those sort of adjustments.

All examples can be downloaded here:

https://samply.app/p/GNrA3eINKjjR1rG1ZOSK
 
MirrorProfiles said:
As well as feeling like the HJS model was dark sounding, I’ve always felt the same about the regular JVM. It’s typically an amp I think of as quite bright and almost twangy, and to get those kind of tones always took some work.

The recent Bogren plugin immediately reminded me of the JVM tones I’m familiar with, so I thought I’d try and dive in a bit closer on the Fractal model.


First the real amp tone. Very typical settings for this amp, you can basically just tweak slightly from 12 o clock and you’ll get something quite nicely balanced.

View attachment 43626

Amp Tone: https://samply.app/p/yXEcY9wp5olKpcUtvXry

My first AxeFX tone was eyeballing settings, trying to be as generous as I can to match the tone. If you put settings like this in, it sounds bloated and farty and not like how you'd expect a JVM. Even taking tolerances into account, it’s quite far off.

JVM Fractal 1: https://samply.app/p/H2fL7vtcjV40mSoFVLYM

Just to prove the tonal difference is beyond pot tolerances and tapers, the next tone sets the presence and treble to both to 10. This ends up sounding a lot closer to the JVM at "typical" settings. But this is already at the limit of what you can do with the tone now, and it just about covers “typical” JVM tones (check where the relative presence knob values are).

JVM Fractal 2: https://samply.app/p/ZN11CW4zVRNoot8YkTVF

Lastly, I did a tone that I just dialled totally by ear. This involved being more heavy handed with the amp EQ, changing the preamp LPF, changing the MV bright cap etc. It's not exact, but it's possible to get in the ballpark. But to get it to sound like a "typical" JVM, you need to get your hands dirty, AND use more extreme settings. I don't really associate the JVM as the kind of amp that needs weird settings or a lot of work to sound good, most people seem to use roughly the same kinds of settings.

JVM Fractal 3: https://samply.app/p/UoOW5WnNljRLE5C3KeHx

Eyeballing settings:

View attachment 43627

Treble+ Presence on 10:

View attachment 43628

Tweaking by ear (TOTALLY different mids, treble, presence settings as well as other deeper tweaks):

View attachment 43629

I've always felt the JVM models didn't really represent my experiences with the amps, particularly for sounding too dark/muffled. I can get close enough to be happy with some tweaks, but this only really works when having the real amp to reference against. I'd WAY prefer to be able to just dial the amp like the real thing and get typical tones with more ease.

The real JVM is an amp I think of as fairly bright/tight/twangy/aggressive. The Fractal model leans more fat/fuzzzy/dark/bloated unless you massage it into something else. It doesn't really remind me of a JVM unless you do those sort of adjustments.

All examples can be downloaded here:

https://samply.app/p/GNrA3eINKjjR1rG1ZOSK
Click to expand...

Excellent work. Thank you for detailing the differences so well. The difference is huge, and I can't believe pot tolerances would be enough to explain that. I don't know the history of JVMs, but are there different revisions of the amp, like there are Dual Rectal Fires or Revv Generators?
 
State of Epicicity said:
Excellent work. Thank you for detailing the differences so well. The difference is huge, and I can't believe pot tolerances would be enough to explain that. I don't know the history of JVMs, but are there different revisions of the amp, like there are Dual Rectal Fires or Revv Generators?
Click to expand...
No not really. In some regards it's an amazing achievement that it's been in continuous production as a "flagship" Marshall for so long. I think it's actually been so successful it's very hard for them to beat it.

Theere is the Satriani model, which Fractal has modelled already. And there are some fairly common mods documented online, but tbh I think the stock JVM sounds best to me. For anyone that thinks the Fractal model sounds correct, go on YouTube and watch some JVM videos and take note of the settings. Then try them in the Fractal.
 
I'll take a look at the model this week but I doubt there's anything wrong. Usually the issue is MV settings. Lower the MV and the amp will be brighter and more aggressive.

Re. the JS models. Our models are based on Joe's personal amp which is not the same as the stock version of the amp. His personal amp is modded and considerably darker than stock.
 
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FractalAudio said:
I'll take a look at the model this week but I doubt there's anything wrong. Usually the issue is MV settings. Lower the MV and the amp will be brighter and more aggressive.
Click to expand...
Thank you, I appreciate that a lot.

I'm finding the tones to be a lot darker, even at MV settings below 1. I think even taking into account the amp having channel and master volumes, the real amp has a reasonable amount of headroom before it loses the sizzle and bite.
 
FractalAudio said:
I'll take a look at the model this week but I doubt there's anything wrong. Usually the issue is MV settings. Lower the MV and the amp will be brighter and more aggressive.

Re. the JS models. Our models are based on Joe's personal amp which is not the same as the stock version of the amp. His personal amp is modded and considerably darker than stock.
Click to expand...
Thanks Cliff! You're a diamond geezer.
 
MirrorProfiles said:
As well as feeling like the HJS model was dark sounding, I’ve always felt the same about the regular JVM. It’s typically an amp I think of as quite bright and almost twangy, and to get those kind of tones always took some work.

The recent Bogren plugin immediately reminded me of the JVM tones I’m familiar with, so I thought I’d try and dive in a bit closer on the Fractal model.


First the real amp tone. Very typical settings for this amp, you can basically just tweak slightly from 12 o clock and you’ll get something quite nicely balanced.

View attachment 43626

Amp Tone: https://samply.app/p/yXEcY9wp5olKpcUtvXry

My first AxeFX tone was eyeballing settings, trying to be as generous as I can to match the tone. If you put settings like this in, it sounds bloated and farty and not like how you'd expect a JVM. Even taking tolerances into account, it’s quite far off.

JVM Fractal 1: https://samply.app/p/H2fL7vtcjV40mSoFVLYM

Just to prove the tonal difference is beyond pot tolerances and tapers, the next tone sets the presence and treble to both to 10. This ends up sounding a lot closer to the JVM at "typical" settings. But this is already at the limit of what you can do with the tone now, and it just about covers “typical” JVM tones (check where the relative presence knob values are).

JVM Fractal 2: https://samply.app/p/ZN11CW4zVRNoot8YkTVF

Lastly, I did a tone that I just dialled totally by ear. This involved being more heavy handed with the amp EQ, changing the preamp LPF, changing the MV bright cap etc. It's not exact, but it's possible to get in the ballpark. But to get it to sound like a "typical" JVM, you need to get your hands dirty, AND use more extreme settings. I don't really associate the JVM as the kind of amp that needs weird settings or a lot of work to sound good, most people seem to use roughly the same kinds of settings.

JVM Fractal 3: https://samply.app/p/UoOW5WnNljRLE5C3KeHx

Eyeballing settings:

View attachment 43627

Treble+ Presence on 10:

View attachment 43628

Tweaking by ear (TOTALLY different mids, treble, presence settings as well as other deeper tweaks):

View attachment 43629

I've always felt the JVM models didn't really represent my experiences with the amps, particularly for sounding too dark/muffled. I can get close enough to be happy with some tweaks, but this only really works when having the real amp to reference against. I'd WAY prefer to be able to just dial the amp like the real thing and get typical tones with more ease.

The real JVM is an amp I think of as fairly bright/tight/twangy/aggressive. The Fractal model leans more fat/fuzzzy/dark/bloated unless you massage it into something else. It doesn't really remind me of a JVM unless you do those sort of adjustments.

All examples can be downloaded here:

https://samply.app/p/GNrA3eINKjjR1rG1ZOSK
Click to expand...
I spent a couple hours on this. Found a couple minor things but those didn't change the tone much, if at all.

I suspect your amp is simply different than our reference amp.

Our reference amp has 47K resistors in series with the treble pot. These resistors reduce the maximum treble. The schematic does not show these. However, the JVM410HJS (Satriani model) schematic shows these and the JS version does have these.

My guess is that Marshall started using the same control board for both versions at some point to simplify things, reduce inventory, etc. Or maybe our reference amp has the wrong control board in it. I doubt it, but it's possible. Regardless, our models are always matched to our reference amp. If you want to send us your amp we can compare them.

The JVM410 is also problematic because the internal layout is poor. The output transformer is on the wrong side of the chassis and causes the output to couple into the input. There's a shield in there but there's still a ton of crosstalk. The net effect is that it causes resonances that are dependent upon the Master Volume. You can test this yourself. Hook the amp to a load-box. Listen to the output at the FX Send (or Preamp Out). Turn the MV up and down and the tone will change dramatically.
 
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FractalAudio said:
I spent a couple hours on this. Found a couple minor things but those didn't change the tone much, if at all.

I suspect your amp is simply different than our reference amp.

Our reference amp has 47K resistors in series with the treble pot. These resistors reduce the maximum treble. The schematic does not show these. However, the JVM410HJS (Satriani model) schematic shows these and the JS version does have these.

My guess is that Marshall started using the same control board for both versions at some point to simplify things, reduce inventory, etc. Or maybe our reference amp has the wrong control board in it. I doubt it, but it's possible. Regardless, our models are always matched to our reference amp. If you want to send us your amp we can compare them.

The JVM410 is also problematic because the internal layout is poor. The output transformer is on the wrong side of the chassis and causes the output to couple into the input. There's a shield in there but there's still a ton of crosstalk. The net effect is that it causes resonances that are dependent upon the Master Volume. You can test this yourself. Hook the amp to a load-box. Listen to the output at the FX Send (or Preamp Out). Turn the MV up and down and the tone will change dramatically.
Click to expand...
Thanks so much for taking the time to check and work out what’s going on, it’s very much appreciated.

Supposing it is an anomaly on the PCB - does that mean altering the tone stack setting in the model would re-voice things closer to the schematic version?

All of these videos on youtube seem to match my own experience with the real thing, where it’s brighter with more kerrang:









Presumably the resistors 47k resistors are on the PCB with the pots. I’ll see if I can check some amps to see if they’re there too. Perhaps Santiago is able to shed some light on it as well.
 
So yep, had it confirmed that the 47k resistors dont belong on the stock amp. They were part of the tweaks JS had done to the original circuit. Production JVM’s that have been in production for a LONG time now will not sound like the Fractal model.

The PCB’s in each amp are also totally different so I can only imagine Cliff’s amp is either an HJS prototype, or has been modded at some point.
 
MirrorProfiles said:
So yep, had it confirmed that the 47k resistors dont belong on the stock amp. They were part of the tweaks JS had done to the original circuit. Production JVM’s that have been in production for a LONG time now will not sound like the Fractal model.

The PCB’s in each amp are also totally different so I can only imagine Cliff’s amp is either an HJS prototype, or has been modded at some point.
Click to expand...
Our reference amp is a a late-model production amp that has never been modded. It was purchased new from Sweetwater.

I'm happy to change the tone stacks but I would need to compare another amp to see if our amp is an anomaly. If you'd like to send your amp to us we'll gladly compare it to our amp.

I can't change an amp model based on one user's opinion or hearsay. Until I have another amp in my possession that doesn't have the 47K resistors I have to assume that they belong there.
 
alexjplant said:
If anybody's in an enterprising mood there's this thread on TGF that the designer of the JVM started. You could probably ask there and get confirmation without having to ship amps back and forth across the country :)
Click to expand...
@MirrorProfiles referenced Santiago (the creator of that thread and the amp) in his post above.

I suspect that might be who he got "confirmation" from.

In any case, Cliff would still need a physical amp to update the model if he was planning to do it.
 
unix-guy said:
Confirmed here that he already checked with Santiago:

https://thegearforum.com/threads/fractal-talk.2745/post-358351
Click to expand...

Ah, thanks for seeing that! So it's something he must have answered in a private message, because I don't see any public posts from him about it. So the question has been answered as to what the difference is, but I was actually asking Santiago a different question, if the original ones were produced without the series resistors or if that was introduced later.

I'm assuming the negative effects of having the transformer on the wrong side would not be a problem in the Axe-FX III (unless Cliff specifically wanted to model that crosstalk!), so I'm curious where this goes.
 
Curious, too... I bought a new JVM 410h about 5 years ago (so I assume it's a newer one) and I like it because it's a bit darker sounding... not bright, fizzy and harsh at all, even at bedroom volume. I ran the physical amp and the Axe III model through the same physical cab for comparison and it's pretty much spot on.

Maybe Cliff is right that they started using the same control board for both the HJS and regular version.

A side note to the videos posted above: I tried to replicate the tone from some of the riffs that are played in the Sonic Drive Studios video. I used a reactive load, the exact same guitar model, the same settings and IR - my amp sounded way less present and bass, mids and treble were off compared to the video. Either SDS did some serious post production, or something did change. The tonal difference was way too big to be explained by the "tone in your fingers". I also saw some of the videos above mention the age of the JVM. On the first clip its a JVM built in 2012.
 
Possum said:
Curious, too... I bought a new JVM 410h about 5 years ago (so I assume it's a newer one) and I like it because it's a bit darker sounding... not bright, fizzy and harsh at all, even at bedroom volume. I ran the physical amp and the Axe III model through the same physical cab for comparison and it's pretty much spot on.

Maybe Cliff is right that they started using the same control board for both the HJS and regular version.

A side note to the videos posted above: I tried to replicate the tone from some of the riffs that are played in the Sonic Drive Studios video. I used a reactive load, the exact same guitar model, the same settings and IR - my amp sounded way less present and bass, mids and treble were off compared to the video. Either SDS did some serious post production, or something did change. The tonal difference was way too big to be explained by the "tone in your fingers". I also saw some of the videos above mention the age of the JVM. On the first clip its a JVM built in 2012.
Click to expand...
Probably a completely stupid thought but does voltages play any role in the tone @FractalAudio
All these guys SDS Jon and Euge are all in Europe so their amps must be seeing 240 V
I remember years ago the scorpions complaint that their Marshall’s did not sound as good in the US so much that they avctually had transformers in the rig so the amps could see the 240
 
I checked with Santiago via PM. He said that it’s not possible to use the same PCB in both amps as the switching etc is totally different. From what I can tell the HJS doesn’t have a seperate board for the pots either (it’s one big PCB). It wouldn’t make sense to use the same boards because the features are different and the Satriani model has been out of production for years. The stock JVM would need a total redesign to accommodate a JVM HJS board. It wouldn’t make any sense, the HJS has been discontinued since about 2018. The 410 has been in production since 2007 - It would be odd to change it now, when sales would have slowed right down. They’d either discontinue it, or they’d have made a song and dance about a Mark II with a new voicing.

Voltages wouldn’t make this drastic of a difference, the effect of the 47k resistor limits the range of the treble pot and essentially re-centres the mid point. It completely explains why the Fractal model sounds different to the majority of JVM’s that have been in continuous production since 2007. This, and filtering after the tone stack was done per Satriani’s request, presumably so the amp is smoother for lead playing. It has nothing to do with the original design or intention of the amp which sounds well balanced and with sensible ranges of the knobs around the 12 o clock position.

If it has been added since, I don’t think it’s for tonal reasons.

Fractal have had JVM models since the Axe FX II days, IIRC. Is it only recently where the voicing has changed? Was the older model purely schematic based? I guess we’ll figure it out eventually.
 
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