Santiago Alvarez (electronics engineer, JVM, YJM, AFD...)

Very cool, welcome!

I'm curious, since you've worked on a lot of flagship tube amps but also some solid state and modeling amps. In your opinion, do you think a good solid state design could get nearly all of the tone of a tube amp? And if so, what's holding solid state technology back from being a true tube replacement for most guitarists (player perception, companies building cheap amps to hit price points, difficulty in engineering, etc.)?

I would love to have a really good Marshall version of a Tone Master amp, something that can nail a Plexi sound all the way up to a modded 800, but using solid state or modeling tech, and being able to scale the volume extremely well, without burning up tubes and running through attenuators.
 
santiall said:
They are pretty much the same amp. The only difference is the JVM2 clean green which is designed specifically for that amp as the JVM4 has a different clean channel that can't be easily integrated in the 2-channel version. Other than that, I think JVM2 CH1 orange and red are JVM4 CH2 orange and red, JVM2 OD channel is JVM OD2. The main pcb is actually the same in all the amps with different firmware and number of tubes of course.
Click to expand...

So basically with the 205 you can get most of the 410 tones from Channels 1/2 and OD2, but not OD1?

A lot of people rave about the Satriani 410, how does it differ from the standard 410H?
 
Jarick said:
what's holding solid state technology back from being a true tube replacement
Click to expand...

@santiall
To add to this question, did you have a chance to work with Nutubes?
Vox announced them several years back as the first breakthrough in vacuum tube technology in decades.

They came out with some lunchbox amps with them, but don't remember hearing anything about them since then.
 
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the-trooper said:
To add to this question, did you have a chance to work with Nutubes?
Vox announced them several years back as the first breakthrough in vacuum tube technology in decades.

They came out with some lunchbox amps with them, but don't remember hearing anything about them since then.
Click to expand...

Those are really interesting, and I was hoping to see a lot more use in amplifiers, but it kind of hasn't gone anywhere.

I just wonder how different the clipping behavior of the Nutube is vs a traditional preamp tube, vs well designed solid state (diodes?), vs digitally modeled clipping.
 
Great question @Jarick . I have heard great things about Softube (and the Code stuff other than maybe the build materials). Some people really dug the JDM stuff as well. I had the Mode Four and loved it. So to my ears; it can be "done"; whether tube, SS or digital. Or a combination.
 
santiall said:
it's rather simple actually. When I joined M back in 2005 they already that a plan to upgrade the TSL and make it the new flagship. The starting point I was given to "take a TSL and add a 4th channel with more gain", so pretty much I took a TSL, put it on a shelf as reference and got a JCM800 2203 as starting point. Then everything snowballed from there, since the circuitry I was working on was quite flexible the three-modes-per-channel idea and the 1 wire controller came by themselves. Initially it was just 4 channels and there were always issues with the multipin connector for footcontrollers...
It is always easy to think that I should have done this and that but the JVM is about 16 years old already... I guess the main change I'd have done is to add the noise gate that I designed for the Kerry King amp (and that now everyone uses in the gate pedals :D) and that was developed just after the JVM was approved for production. The parallel loop is also anachronic nowadays, it made sense in 2000 but it is outdated, it is not necessary anymore and many users don't understand it.
Plans?, I don't work there anymore... lips sealed!


I always found the DSL a bit boomy/loose on the lower and scooped or perhaps fizzy. I understand that it records quite nicely and for some rock music is very good but it was just not my thing (apart then being an engineer it always bothered me the mess of wires inside...)
Actually the DSL has 1 more gain stage than the JVM but I'd say the JVM is tighter, heavier than a DSL


I guess that'd change every week, no, every day :D but probably I'd end settling in single channel, master volume but with some sort of power amp attenuator so you can use the master to control the power amp distortion, high gain, 3 or 4 stages and most likely with a simple booster and gate, FX loop and probably EL34s



Hi Leon, looking forward to that demo, hopefully with a Sony V77 haha. It is actually a completely different amp to the DSL, there may be some similarities like the tone controls and cathode follower but I haven't used any DSL circuitry in the JVM, not even the transformers, we went back to JCM800 magnetics.
I did not have any single issue working with Yngwie, actually it was real fun and I just wish we had worked in more projects. I guess we came along quite well and there has been mutual respect in both directions from day one. Even I was so intimidated when meeting him first time, you know, he is one of my ever-favorite players, but he was also sooooo excited to talk to a Marshall engineer
He came to us with a clear idea of what he wanted and the whole process was very smooth. As said, I just wish there were more together


They are pretty much the same amp. The only difference is the JVM2 clean green which is designed specifically for that amp as the JVM4 has a different clean channel that can't be easily integrated in the 2-channel version. Other than that, I think JVM2 CH1 orange and red are JVM4 CH2 orange and red, JVM2 OD channel is JVM OD2. The main pcb is actually the same in all the amps with different firmware and number of tubes of course.


thanks! I actually don't know myself. I think I was already out of M when the HJS was discontinued and, just speculating, probably the numbers were low when compared to the standard JVM and someone thought it didn't make sense to endorse him anymore? Personally, I think it was a mistake but hey, there you go. In any case, those sorts of commercial decisions were always taken without R&D input, it is not that some parts were obsolete and difficult to find in numbers.
sometimes people ask me to do some experiments/mods but the main problem is that I'm based in Hong Kong, just thinking of shipment costs will make you think twice about that idea... as said, I've done some work for some artists and other players but there is the logistics and sometimes my own available time issues. Thank you so much for the proposal, as said I'm open but it may not make any sense...
Click to expand...

This is so cool. Love the behind the scenes stuff with Yngwie. Thanks for sharing! :beer
 
Whizzinby said:
Also, Tonemaster Marshall!?!? Any thoughts on what Fender is doing with their digital amps, and if you think something similar might work for Marshall, like a 212 Marshall ToneMaster JCM800TM Combo, or Plexi, Silver Jubilee, JVM etc.
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sorry I missed this part in my reply before. I haven't tried any Tonemaster myself yet but they seem to be quite good and doing well. I won't be surprised if other brands try to do the same but I think it can be challenging to get them right when the original amp is played with overdrives and so on, especially the way the input tube distorts
DrewJD82 said:
While you were with M, did you ever hear of any talk of an Eric Johnson signature Plexi?
Click to expand...
no, not at all. I heard Eric Johnson did some stuff for Marshall in the early 2000s but that was before I joined them.
Jarick said:
Very cool, welcome!

I'm curious, since you've worked on a lot of flagship tube amps but also some solid state and modeling amps. In your opinion, do you think a good solid state design could get nearly all of the tone of a tube amp? And if so, what's holding solid state technology back from being a true tube replacement for most guitarists (player perception, companies building cheap amps to hit price points, difficulty in engineering, etc.)?

I would love to have a really good Marshall version of a Tone Master amp, something that can nail a Plexi sound all the way up to a modded 800, but using solid state or modeling tech, and being able to scale the volume extremely well, without burning up tubes and running through attenuators.
Click to expand...
you could write a whole book about it :D. I guess the digital modeling is already quite good, actually excellent but a guitar player also wants to play real tube amps and, regardless how good the modeling is, it can be difficult to 'force' people to play a modeler. It is a preference issue and you can't change that, it's been so many years since the modelers appear and you can see that the tube amps are still there.
I think the tube amp will remain and the solid-state / practice / low end market will evolve towards more and more digital. At the end a digital amp is, bluntly, an A/D converter, a DSP, a D/A converter and a power amp. The hardware design goal is to make it quiet and with a dynamic range as high as you can, then everything else goes to the DSP. Once the algorithms are perfected there is no reason why some very good modeling can't be found in a very cheap amp, the hardware is always getting cheaper or more powerful for the same price.
As hinted above, my main concern about a Tonemaster M-Style amp would be how it behaves when someone sticks an 18V booster to the input...


Whizzinby said:
So basically with the 205 you can get most of the 410 tones from Channels 1/2 and OD2, but not OD1?

A lot of people rave about the Satriani 410, how does it differ from the standard 410H?
Click to expand...
yes, but you can change I think 3 or 4 parts and you convert the OD2 into OD1

the HJS is, at end, quite different to the standard JVM. It has less gain, it is more open and less tight. A bit darker too. As Joe always says, he needs to play single notes for 2h every night and a more metal-style amp can get tiring. He also likes the amp to respond in a certain way to the way he picks and attacks the strings but, with a bit of boost you can get the amp quite tight and modern sounding too.

the-trooper said:
@santiall
To add to this question, did you have a chance to work with Nutubes?
Vox announced them several years back as the first breakthrough in vacuum tube technology in decades.

They came out with some lunchbox amps with them, but don't remember hearing anything about them since then.
Click to expand...
I remember doing some very quick experiments and measurments back when they were launched, it was more curiosity than anything else as they were VERY expensive. It was like, why would I have to spend $$$ in a Nutube when we can use a real tube for $

Jarick said:
Those are really interesting, and I was hoping to see a lot more use in amplifiers, but it kind of hasn't gone anywhere.

I just wonder how different the clipping behavior of the Nutube is vs a traditional preamp tube, vs well designed solid state (diodes?), vs digitally modeled clipping.
Click to expand...
I don't really know but actually and it'll be difficult to explain in words anyway but when working with distortion, a lot of the tone you hear has to do with how you filter if afterwards. Just take any distortion pedal and play it through a Hi-Fi amp, sounds like crap. Insert an IR and suddenly it sounds 'right'. That's what the whole guitar amp chain does, you clip here and there, add some sort of tone control, some filtering here and there too and then pretty much rely on the speakers to shape the tone. Again, try to record the raw signal from a tube amp, you won't be pleased :D
Another different issue is how it feels to the player and probably here is when the tubes still have some advantage against modeling but, again, it depends on the player, the model, etc etc.
I prefer seeing all these decisions as options rather than a competition. Maybe for this application I prefer a modeler but then I feel like playing a tube amp.

JiveTurkey said:
Great question @Jarick . I have heard great things about Softube (and the Code stuff other than maybe the build materials). Some people really dug the JDM stuff as well. I had the Mode Four and loved it. So to my ears; it can be "done"; whether tube, SS or digital. Or a combination.
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they are a great bunch of guys in there. Very professional and passionate about what they do. I worked on the Console Fader, a USB controller, with them.
I think the JMD-1 just came too late to the party, even after the Line 6 experiments with Bogner were not successful, so it was a bit doomed from the begining but it is a very good sounding amp.
 
Jarick said:
Did you see this video? Curious what your thoughts are.

Click to expand...

yeah, just watched it, thanks for the hint.
It is quite accurate with what actually is happening inside an amplifier, pedal, etc. and more or less what we talked about before. Pretty much what one does is to 'condition' the signal, clip it, filter it and repeat or rearrange as necessary. A perfect example for this are the Tech 21 pedals which just have an op-amp clipping rail to rail and then they filtered the signal to create the diverse amplifier models.
Although the principle is that one in the video, what will make a lot of difference are the dynamics. Maybe the tone is the 'same' but it may be hard to play, or doesn't sustain, etc...
we could talk hours and hours about the tone shaping and how to accomplish different effects with different circuits just to conclude that the most important bit will be what IR we use at the end :rofl
 
To me the JVM is the greatest functional tube amp switcher in the history of amp making and I seriously mean it.

I certainly appreciate you were somewhat bound & gagged, circuit design wise, as it had to sound like a Marshall of course.

If your design was 100% applied to a non tied down Marshall sounding circuit, I believe your amp would be THE ultimate amp with no competition in sight for the rest of tube amp history going forward.

So, a big thank you Santiago for showing us what has, could & can be achieved .....................beyond a Marshall if implemented elsewhere.

:beer :beer :beer :beer :beer :beer :beer :beer :beer :beer
 
ManWithGas said:
To me the JVM is the greatest functional tube amp switcher in the history of amp making and I seriously mean it.

I certainly appreciate you were somewhat bound & gagged, circuit design wise, as it had to sound like a Marshall of course.

If your design was 100% applied to a non tied down Marshall sounding circuit, I believe your amp would be THE ultimate amp with no competition in sight for the rest of tube amp history going forward.

So, a big thank you Santiago for showing us what has, could & can be achieved .....................beyond a Marshall if implemented elsewhere.

:beer :beer :beer :beer :beer :beer :beer :beer :beer :beer
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thanks a lot, truly appreciated, cheers!
I guess back in the day, we are talking 2005-2006, the main constraint was to make it easy to assemble and relatively simple circuit-wise. The company was more focused on getting rid of the wiring complication of the JCM2000s and ongoing problems with multipin connectors for footswitches and the likes.
It needed of course to sound like a M but there was freedom there. What we didn't want to do was just to put there yet another Soldano copy... but the first channel is Fenderish and the OD2 is somehow voiced like a SLO (and actually, I think that anything with the script M logo on it will make people think that it sounds like a Marshall :D)
 
You mentioned involvement with Blackstar---which I have heard was started by longtime Marshall
employees who left to start Blackstar. Did you have any involvement with either of these amps?

Thanks. :beer

20221012_152313.jpg
20221012_153113.jpg
 
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Hi Santiago. My question is about using a long tail phase inverter in a 1 watt push pull style amp. What would be a good method for taming the stock 1987 Marshall values down enough for the 12AU7? Add resistance to the tail?

I built one a while back that has a 1987 preamp with a self split 12BH7. It needs a minor rebuild and I am hoping to add in the PI. Thanks!
 
la szum said:
You mentioned involvement with Blackstar---which I have heard was started by longtime Marshall
employees who left to start Blackstar. Did you have any involvement with either of these amps?

Thanks. :beer
Click to expand...
Hi, no, not on those. They developed those when they were starting if I am not wrong, perhaps back in 2005-2006. They had left Marshall a couple of years before that and, actually, that's why Marshall had openings for engineers and how I got my job there :D

PatF said:
Hi Santiago. My question is about using a long tail phase inverter in a 1 watt push pull style amp. What would be a good method for taming the stock 1987 Marshall values down enough for the 12AU7? Add resistance to the tail?

I built one a while back that has a 1987 preamp with a self split 12BH7. It needs a minor rebuild and I am hoping to add in the PI. Thanks!
Click to expand...
I think you will be fine with the usual values. I have done experiments with the phase inverters for low power amps with 12AX7, 12AT7 and 12AU7 and I think I always ended using the usual 100k-82k anode resistors and 470Ω cathode resistor (that's the one that affects the gain the most). Maybe you will be better adjusting the input level of the phase splitter, so it doesn't distort way too much in a nasty way.
You may also increase the 470Ω to reduce the gain but if your power amp has feedback it "may be better" to have as much feedback gain as possible, then adjust the levels outside.
You may also need to be careful of not overdriving the power tubes too much to the point of blocking them, you can experiment with relatively large value screen stoppers there.
 
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