laxu
Rock Star
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Yeah my bad, I think that is the exact document I used.
Santiago Alvarez (electronics engineer, JVM, YJM, AFD...)
- Thread starter santiall
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no problem of course, 35mA is the more or less ballpark figure to bias a 100W amp. 45mA is rather high but there you go, that's what they were suggesting
@santiall I understand you had your hand in the 1 watt anniversary amps? I have the JMP1C and it really seems like the best off the shelf solution for power tube saturation at bed/living room volume. Any idea why this concept never really caught on? Logistical issues or cost vs perceived value maybe?
Slightly related, but I always wondered about the voicing on the JMP 1 watt, is it modeled after the high sensitivity high treble input? Since there is no presence or mid control, are those effectively on 10? Any cool lore about that series of amps you could share would be very cool!
Slightly related, but I always wondered about the voicing on the JMP 1 watt, is it modeled after the high sensitivity high treble input? Since there is no presence or mid control, are those effectively on 10? Any cool lore about that series of amps you could share would be very cool!
Life Eats Life
Roadie
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- 693
What is OD-1 modeled after?get yourself a JVM, OD1 green + tubescreamer and you are 95% there
Life Eats Life
Roadie
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- 693
I would say as close as the JVM can get to a Bassman?
It’s also the best sounding mode with a Strat.
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- 197
Hi, yeah, I'm not sure how the project originated but the idea was to have a series of amps reminiscent of the past 50 years of Marshall and the 4 engineers that were working there would be involved. James Marchant took care of the JTM-1 and the JCM-1, Steve Dawson of the JMP-1, Jonathan Lagstaff the JMP-1 "1W preamp version" and I did the JVM-1. The thing is that originally the DSL1 was going to be a 1W version of the JMP-1 preamplifier but for whatever reasons didn't happen so they assigned me the DSL-1 as well.
Another interesting fact is that they had planned to sell them for limited time, so the year was split and every amp would have it's own time but that didnt' happen so, at the end, the JTM-1 sold for the whole year, the JVM-1 for like 3 months as they didn't stop one amp to start the other and overlapped all of them...
Going back to 2012, the 1W was more of a "cute thing" than a proper product I guess. The mini amps were in their infancy and probably that's the reason why it was never pursued but who knows.
On the JMP-1 side, I don't really know but I have asked Steve Dawson, the designer, this is what he just wrote me back:
The JMP 1 Watt was designed to react like it was channel jumped. At least with the limited amount of stages I had. I remember intending to put a mid control on it, but product people insisted that it wouldn't, so the range would gather more features as they went through the various flagships they represented. The Presence (tonally)was set by a capacitor over the lower resistor of the final divider chain before the power amp.I remember experimenting with various configurations of the 12A*7 preamp valves in the power amp to give me the right feel for what I was after. My references for classic JMP tones were ACDC and Lizzy mainly.
The tone stack is not the traditional topology. I just voiced the amplifier signal path during development.
hope it helps!
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- 197
the JVM was developed on a 2203 chassis, it wasn't a copy of anything but, back in those days, the main competitors were the 5150, the Diezels, some Bogners and the Dual Rectifier. It isn't another copy of a SLO-100
The clean channel is very black face Fender, the Crunch green could get you near the bassman as it is more similar to a JTM45 / Plexi style but the tone control has different values so the overal character won't be that similar
Very cool information. I feel like most people who just play at home are well served by mini amps like these. It's a great idea and I wish more other companies (or even Marshall) would have some newer releases of things like this.
Maybe I'll open up my JMP1c and change some caps to get it sounding more like the bright channel...
Really cool of you to grab that information for us here!
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you are welcome, and thanks to Steve Dawson for sharing his insights on the JMP-1.
1W amps, I don't know... probably the market dictates that something like a 20W amp is already "home friendly" with a small attenuator and it's size is small enough to use at home. It is also loud enough for the eventual band practice but a 1W has more limited usage. I'd imagine that otherwise they would be more popular, who knows, just guess work here...
laxu
Rock Star
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To me the sub-5W amps from most brands are pretty stupid products. Not loud enough for stage if you want cleans, not quiet enough for home, often low on features and with tiny transformers etc so they don't even sound that great.
The mistake Marshall makes on their 20W range is not also providing some very low power scaling mode that would make them more home friendly. I don't know why they didn't just replicate the Origin series low/mid/high power scaling on the 20W vintage model range, or throw in e.g a defeatable PPIMV.
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the original Origin, as I had designed it, had two power settings, 20W in class AB, 5W in class A (something like 50W and 5W in that version). Then it had a 4 or 5 stepped resistive attenuator on the back plus some sort of DSP/IR processed emulated out plus reverb. This in 2016. For whatever reason, when I left, they removed all that...
There are some Paul Gilbert videos in YouTube using that prototype, an open chassis. He put it inside a purple wooden box later on.
Hola Santiago!
Ist been a while i have already asked sone questions.
Now by revisiting this thread i got. some questions again tobte JVM410h
You Mentorinnen before that the Channel volume Should be relatively high.
Do you habe some more tips and recommendations for the JVM ?
What dB setting do you recommend normally for the FX Loop? My Board can handle Both settings so im wondering what should be „better“
How would you dial in a JVM ?
What would your 80s Like JCM800 Channel and settings be ?
Maybe you got some Great Tips :)
Thanks again!
Ist been a while i have already asked sone questions.
Now by revisiting this thread i got. some questions again tobte JVM410h
You Mentorinnen before that the Channel volume Should be relatively high.
Do you habe some more tips and recommendations for the JVM ?
What dB setting do you recommend normally for the FX Loop? My Board can handle Both settings so im wondering what should be „better“
How would you dial in a JVM ?
What would your 80s Like JCM800 Channel and settings be ?
Maybe you got some Great Tips :)
Thanks again!
- Messages
- 197
Hi, hola!
in general you always want to deal with large signals, for signal to noise reasons. The amount of noise injected after the channel volumes is minimal so it doesn't really matter that much but, as a principle, you should use as much signal as you can. If you have the channels very low and then you turn the master high you will amplify some extra noise that you don't want.
If possible I'd go for line level, +4dB, again same reason. You don't want to attenuate to -10dB, then bring the level back to +4dB internally if you can avoid it of course.
How I dial a JVM... usually everything around 12 o'clock, perhaps the bass and treble around 1o'clock, mid around 11o'clock. Gain around 1 or 2 o'clock. The settings on the clean channel could be a bit more extreme than thatbut I usually stay around those zones.
80s JCM800, crunch orange or red and a booster, Boss SD-1 for me most likely. OD-1 green is very nice with some boost, OD-1 orange without boss is also pretty interesting for those tones. A bit of reverb for me please :)
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Where do you normally like to run your presence and depth?
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both at zero haha, sorry to be this boring
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This is amp heresy!!!!
Depth and presence both at 2 o'clock!!! The amp sounds absolutely MEGA that way!
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No this is great. A lot of us have a weird reflex about maxing or reducing a knob value to zero so it makes it easier for us to try it without feeling like something must be wrong.
Sounds awesome. Have been using these settings this morning.
SillyOctpuss
Shredder
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- 1,095
No this is great. A lot of us have a weird reflex about maxing or reducing a knob value to zero so it makes it easier for us to try it without feeling like something must be wrong.
Sounds awesome. Have been using these settings this morning.
Yup got to agree. I've spent tonight with the presence and resonance down at zero and hammering the crunch channel with a tone bender mk1 I've been testing out transistors in and damn it's sweet
@Whizzinby for your pedal recommendations thread you need to try a tone bender with this amp. It's really great, it's one of the best distortions I've ever heard but it's also a fuzz.
