L
Little Pigbacon
Guest
Re: NAD: Marshall JVM410H
What kinds of mods do you have? I see the four knobs.
What kinds of mods do you have? I see the four knobs.
Gone_Shootin
New member
Re: NAD: Marshall JVM410H
Let's see if I can remember what all I've done.....
The little switch by the input is for the Plexi Cap mod. I hindsight, I wish I would've skipped the switch and hardwired the cap. This mod makes the amp sound more throaty.
The knobs by the Clean Channel, OD1, and OD2 are for the mid sweep mod for each of those channels. The mod replaces the slope resistor with a 100k pot and a 22k resistor. It lets you move the focus of the midrange control up and down in the sound spectrum and helps to mimic the midrange control of other amps. For instance, alot of Fender Blackfaces had 100k slope resistors. While 33k to roughly 50 something k is Tweed/Marshall territory. This allows you to dial it in wherever you want. It also does effect the other tone controls too. When I have it turned up, it'll also push the mid control down into that gray area between low mids and highs bass, which is kinda handy if you downtune and want to turn up the bass knob without sounding too flubby or too tubby.
The knob by the Crunch Channel is for the One Wire/Randy Rhoads mod. It's a take on a popular mod from the early '80s where one of the resistors (can't remember which one it is without digging out my notes at home) would be swapped out to increase gain. This mod uses a pot and a resistor to allow you to vary the gain in the third gain stage. It effects the Crunch and OD channels. And in regards to the Crunch Channel, you can get gobs of gain out if it if you want, but get too happy with the knob and it can oscillate.
Around back I have a knob for the Negative Feedback mod. It replaces the negative feedback resistor with a pot and a resistor to allow you to dial in how much or little headroom you want in the amp. The greater the resistance, the less negative feedback, which creates less headroom. So you can go from an ultra clean power section all the way to a virtual lack of headroom, similar to a Vox.
Other mods I've done include removing the heater fuses. Mine is from one of the early runs in 2007 that had them, and they caused problems, so Marshall gave their blessing to their althorized repair techs to remove them. I did it myself.
But wait, there's more:
Clean Channel Blackface mod. This made the clean channel sound better, more like a Fender...Not exactly, but close. The mid sweep mod put the icing on the cake.
Crunch Channel 1959 Plexi mod. This just brings the Crunch Channel more in line with 1959 Plexi specs.
OD1 JCM800 2203 mod. This brings OD2 closer to 2203 specs. In hindsight, I wish I hadn't done this one. It made the channel sound more tubby to my ears.
OD2 Rectifier mod. This brings OD2 closer to an older 2 channel Mesa Rectifier. I liked this mod. It still has a Marshally vibe because of the JVM's 1959 based power section, but it sounds more aggressive. It made it my favorite distortion channel on the amp.
I'm trying to remember, but that's all I've done so far. Someday I do want to add a choke, redo OD1 into something more like what I've done to OD2, and maybe try a bigger cap for the Plexi Cap mod.
And as far as preamp tubes go, IIRC, I have a Mullard RI in V1, a Tung-Sol RI in V2, and the rest of the preamp is JJs. And the phase inverter is also a JJ (I've discovered that JJs add a little more of a growl in this position).
Let's see if I can remember what all I've done.....
The little switch by the input is for the Plexi Cap mod. I hindsight, I wish I would've skipped the switch and hardwired the cap. This mod makes the amp sound more throaty.
The knobs by the Clean Channel, OD1, and OD2 are for the mid sweep mod for each of those channels. The mod replaces the slope resistor with a 100k pot and a 22k resistor. It lets you move the focus of the midrange control up and down in the sound spectrum and helps to mimic the midrange control of other amps. For instance, alot of Fender Blackfaces had 100k slope resistors. While 33k to roughly 50 something k is Tweed/Marshall territory. This allows you to dial it in wherever you want. It also does effect the other tone controls too. When I have it turned up, it'll also push the mid control down into that gray area between low mids and highs bass, which is kinda handy if you downtune and want to turn up the bass knob without sounding too flubby or too tubby.
The knob by the Crunch Channel is for the One Wire/Randy Rhoads mod. It's a take on a popular mod from the early '80s where one of the resistors (can't remember which one it is without digging out my notes at home) would be swapped out to increase gain. This mod uses a pot and a resistor to allow you to vary the gain in the third gain stage. It effects the Crunch and OD channels. And in regards to the Crunch Channel, you can get gobs of gain out if it if you want, but get too happy with the knob and it can oscillate.
Around back I have a knob for the Negative Feedback mod. It replaces the negative feedback resistor with a pot and a resistor to allow you to dial in how much or little headroom you want in the amp. The greater the resistance, the less negative feedback, which creates less headroom. So you can go from an ultra clean power section all the way to a virtual lack of headroom, similar to a Vox.
Other mods I've done include removing the heater fuses. Mine is from one of the early runs in 2007 that had them, and they caused problems, so Marshall gave their blessing to their althorized repair techs to remove them. I did it myself.
But wait, there's more:
Clean Channel Blackface mod. This made the clean channel sound better, more like a Fender...Not exactly, but close. The mid sweep mod put the icing on the cake.
Crunch Channel 1959 Plexi mod. This just brings the Crunch Channel more in line with 1959 Plexi specs.
OD1 JCM800 2203 mod. This brings OD2 closer to 2203 specs. In hindsight, I wish I hadn't done this one. It made the channel sound more tubby to my ears.
OD2 Rectifier mod. This brings OD2 closer to an older 2 channel Mesa Rectifier. I liked this mod. It still has a Marshally vibe because of the JVM's 1959 based power section, but it sounds more aggressive. It made it my favorite distortion channel on the amp.
I'm trying to remember, but that's all I've done so far. Someday I do want to add a choke, redo OD1 into something more like what I've done to OD2, and maybe try a bigger cap for the Plexi Cap mod.
And as far as preamp tubes go, IIRC, I have a Mullard RI in V1, a Tung-Sol RI in V2, and the rest of the preamp is JJs. And the phase inverter is also a JJ (I've discovered that JJs add a little more of a growl in this position).
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JeffB
Let it B
MkIII Renegade
New member
Re: NAD: Marshall JVM410H
Congrats. I have one, and it is certainly one of the best amps Marshall has ever made, and without a doubt the most versatile. I had been jonesing for a 30th Anniversary purple tolex, but couldn't seem to find one, so I settled on a TSL100. The TSL was a disappointment to me overall and suffered from a thin/harsh tone under high gain, and wasn't even particularly loud. I had to sell it during the Great Recession of 2009. Eventually, I started to miss the Marshall '80s thrash rhythm tone too much, and nothing else does it like a real Marshall, so I got the JVM. The OD1 channel does a very good job of capturing a hot rodded JCM800, and a lot more! Back when I had my original 2203, it needed a EQ or Tube Screamer pedal boost for lower volumes, and the clean channel wasn't really passable. The JVM has all the bases covered for the Marshall sound!
Congrats. I have one, and it is certainly one of the best amps Marshall has ever made, and without a doubt the most versatile. I had been jonesing for a 30th Anniversary purple tolex, but couldn't seem to find one, so I settled on a TSL100. The TSL was a disappointment to me overall and suffered from a thin/harsh tone under high gain, and wasn't even particularly loud. I had to sell it during the Great Recession of 2009. Eventually, I started to miss the Marshall '80s thrash rhythm tone too much, and nothing else does it like a real Marshall, so I got the JVM. The OD1 channel does a very good job of capturing a hot rodded JCM800, and a lot more! Back when I had my original 2203, it needed a EQ or Tube Screamer pedal boost for lower volumes, and the clean channel wasn't really passable. The JVM has all the bases covered for the Marshall sound!
L
Little Pigbacon
Guest
Re: NAD: Marshall JVM410H
I can't even... That's intense. I don't know if I could bring myself to make that many mods to a fairly expensive amp. I might have to be content with what I could do with pedals.
I can't even... That's intense. I don't know if I could bring myself to make that many mods to a fairly expensive amp. I might have to be content with what I could do with pedals.
Gone_Shootin
New member
Re: NAD: Marshall JVM410H
I don't blame ya. I read and reread the info about the mods for months before I even bothered to turn on the soldering station. It's definitely something you have to commit to, and since the amp is so complex, it's tedious work.
I don't blame ya. I read and reread the info about the mods for months before I even bothered to turn on the soldering station. It's definitely something you have to commit to, and since the amp is so complex, it's tedious work.
Gone_Shootin
New member
Re: NAD: Marshall JVM410H
For those of you that were talking about Svetlana EL-34s, today I had the chance to wring the ones I threw in my JVM. I have to say that at volume they sound pretty good. They have a little more of a kerrang going on rather than the growl that the Winged Cs have. So they aren't really any better or worse, IMHO, just different.
But the amp still started cutting out after it got good and warmed up. So I guess I didn't need to swap and bias the power tubes and probably have a preamp tube starting to go. Oh well, I guess that means that I can save the Winged Cs for special occasions! :headbang:
For those of you that were talking about Svetlana EL-34s, today I had the chance to wring the ones I threw in my JVM. I have to say that at volume they sound pretty good. They have a little more of a kerrang going on rather than the growl that the Winged Cs have. So they aren't really any better or worse, IMHO, just different.
But the amp still started cutting out after it got good and warmed up. So I guess I didn't need to swap and bias the power tubes and probably have a preamp tube starting to go. Oh well, I guess that means that I can save the Winged Cs for special occasions! :headbang:
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L
Little Pigbacon
Guest
Re: NAD: Marshall JVM410H
Today I ordered a full set of tubes for mine. JJ EL34 matched quartet, and five Electro-Harmonix 12AX7's, plus a bonus 12AX7 that's balanced so I can try the phase inverter either balanced or not.
I've also read up on biasing the JVM. I don't think I'm going to get electrocuted, but I will probably destroy the amplifier.
Today I ordered a full set of tubes for mine. JJ EL34 matched quartet, and five Electro-Harmonix 12AX7's, plus a bonus 12AX7 that's balanced so I can try the phase inverter either balanced or not.
I've also read up on biasing the JVM. I don't think I'm going to get electrocuted, but I will probably destroy the amplifier.
I keep looking at these every so often, as they've got midi, but can never figure out how I'd put it all together to be easily moved about.
JOLLY
Super Simonologist
Re: NAD: Marshall JVM410H
This is the only thing that I've ever recorded with my JVM410H and a Marshall 1960 cabinet with the g12t75's. All I did was put everything on 7 on the yellow channel of OD1.
http://www.soundclick.com/html5/v3/player.cfm?type=single&songid=11737219&q=hi&newref=1
That just sounds weird to me. Every single amp I've played through a cabinet with vintage 30's has this weird buzziness/fizziness thing to it, unless said amp was designed around the V30. The JVM410H was designed around using the G12t75. I love the way it sounds with said speaker. Actually, I love the way most amps sound with said speaker. However, the only time I use a g12t75 speaker is in my Marshall 1960A/1960B cabinets. When I first got my JVm410H, the only cabinet I had was my Sheffield loaded Peavey 5150 cabinet. It sounded good through that cabinet. I had a friend bring over his V-30 loaded Marshall cabinet, and I thought it sounded like crap. I the got lucky and found a couple of 1960 cabinets on Craigslist with the g12t75's, and I just love that sound.
This is the only thing that I've ever recorded with my JVM410H and a Marshall 1960 cabinet with the g12t75's. All I did was put everything on 7 on the yellow channel of OD1.
http://www.soundclick.com/html5/v3/player.cfm?type=single&songid=11737219&q=hi&newref=1
L
Little Pigbacon
Guest
Re: NAD: Marshall JVM410H
I had the opposite experience with a TSL100 going from G12-T75's to Vintage 30's. Granted, they were Mesa Vintage 30's, but they sounded so much better for most of the tones I was going for.
Still, sometimes the G12-T75's were just the right thing. Malmsteen. Jazz. I wasn't playing Strat-O-blues in those days, so I don't know which I would have preferred for that.
I had the opposite experience with a TSL100 going from G12-T75's to Vintage 30's. Granted, they were Mesa Vintage 30's, but they sounded so much better for most of the tones I was going for.
Still, sometimes the G12-T75's were just the right thing. Malmsteen. Jazz. I wasn't playing Strat-O-blues in those days, so I don't know which I would have preferred for that.
Lake Placid Blues
New member
Re: NAD: Marshall JVM410H
I went through a period of hating my V30s and went to almost all G12Ms, while my V30s sat in storage. A few years ago I pulled them out of storage and started liking them a bit again. last year I built two 2x12s and I loaded one up with V30s and the other one with G12Ms. The V30 loaded one sounds better in my opinion. The other day I was so struck by how warm and rich it sounded, that I spent over an hour listening to it on axis, off axis, tilted up, not tilted, close up, far away, and it never sounded harsh, or spiky, or ice picky at all. Maybe it is just that room. I need to haul the G12m loaded cab over to the place with V30 loaded one and A/B them in the same room.
Just tonight I plugged into a V30 loaded 1x12 in the same room as where I have been using the G12M loaded 2x12. it sounded not so good; a little buzzy and lacking in bass compared to the G12M loaded 2x12. Of course it's only a 1x12, though. I tried a G12T75 in the cab thinking it would add some bass to the little 1x12 cab. It did, but it also added treble. A lot more treble than i care for. Maybe it's just the room. But well broke in V30s sound great in most places, in my opinion. And with most amps.
I liked the JMD more with just about every model with V30s compared to the G12T. The exception was the clean presets. I thought the G12T75 got better cleans. The V30s are darker clean, but still the cleans were acceptable.
The JVM has strong upper mids on OD1 by my - admittedly limited- experience. It would not surprise me if the G12T sounds good with that.
I went through a period of hating my V30s and went to almost all G12Ms, while my V30s sat in storage. A few years ago I pulled them out of storage and started liking them a bit again. last year I built two 2x12s and I loaded one up with V30s and the other one with G12Ms. The V30 loaded one sounds better in my opinion. The other day I was so struck by how warm and rich it sounded, that I spent over an hour listening to it on axis, off axis, tilted up, not tilted, close up, far away, and it never sounded harsh, or spiky, or ice picky at all. Maybe it is just that room. I need to haul the G12m loaded cab over to the place with V30 loaded one and A/B them in the same room.
Just tonight I plugged into a V30 loaded 1x12 in the same room as where I have been using the G12M loaded 2x12. it sounded not so good; a little buzzy and lacking in bass compared to the G12M loaded 2x12. Of course it's only a 1x12, though. I tried a G12T75 in the cab thinking it would add some bass to the little 1x12 cab. It did, but it also added treble. A lot more treble than i care for. Maybe it's just the room. But well broke in V30s sound great in most places, in my opinion. And with most amps.
I liked the JMD more with just about every model with V30s compared to the G12T. The exception was the clean presets. I thought the G12T75 got better cleans. The V30s are darker clean, but still the cleans were acceptable.
The JVM has strong upper mids on OD1 by my - admittedly limited- experience. It would not surprise me if the G12T sounds good with that.
Lake Placid Blues
New member
Re: NAD: Marshall JVM410H
Mine (except for one) are Mesa spec as well. Now that they have 20 years on them and have aged, as well as being thoroughly broke in, they have really started to sound nice.
Mine (except for one) are Mesa spec as well. Now that they have 20 years on them and have aged, as well as being thoroughly broke in, they have really started to sound nice.
JeffB
Let it B
GoldenVulture
Braindeadologist
Re: NAD: Marshall JVM410H
L
Little Pigbacon
Guest
Re: NAD: Marshall JVM410H
Who's that?
Who's that?
Nostalgic Distortion
New member
Re: NAD: Marshall JVM410H
Sweetness!!!!
I mean the amp, not the science chick with pink hair. I'm not sure who that is so I don't want to offend anyone!!!
Sweetness!!!!
I mean the amp, not the science chick with pink hair. I'm not sure who that is so I don't want to offend anyone!!!
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L
Little Pigbacon
Guest
Re: NAD: Marshall JVM410H
Why is she the same color as her hair?
Why is she the same color as her hair?
