Santiago Alvarez (electronics engineer, JVM, YJM, AFD...)
- Thread starter santiall
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yeah, thanks! there are always some "tone references" when designing stuffThose clips sound killer! Nice mix of AC/DC style thrak and VH brown
MirrorProfiles
Rock Star
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You're an absolute hero and those tone demo's sound amazing. Do you find yourself tinkering and modding existing amp circuits? Are there any schematics or circuits that have particularly inspired you or changed how you approach designing something?
Also, it must be fascinating to balance the circuit design with something that is manufacturable in a feasible and cost effective way. Its quite remarkable to me how amazing amplifiers can be made affordably by making careful calls on where to make compromises. Are there any features or designs you'd love to use but are just totally unfeasable for mass production?
Also I'd be curious which guitar amp myths you read online you feel are just flatly wrong?
and are there any opinions you have about design that maybe some people may find unique?
Also, it must be fascinating to balance the circuit design with something that is manufacturable in a feasible and cost effective way. Its quite remarkable to me how amazing amplifiers can be made affordably by making careful calls on where to make compromises. Are there any features or designs you'd love to use but are just totally unfeasable for mass production?
Also I'd be curious which guitar amp myths you read online you feel are just flatly wrong?
and are there any opinions you have about design that maybe some people may find unique?
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well, thanks!. Yeah, sometimes I tinker with other amps and existing circuits. Not necessarily tube amps but sometimes pro-audio and the likes. Regarding tube amps, I rather keep them original as usually modified units will lose collectable value so if I modify or experiment with them I keep the mods reversible. I tend to 'abuse' more some of the prototypes I have bought over the years as those are already modified anyway and they are unique in their own way.
that has a lot to do with experience, amount of units to be produced, price of the product, etc... for example if you are gong to make only 100 units and sell them for 3,000USD then you don't care to save a couple of USD, but if you are going to make 300,000units a 1$ saving is a lot. Now the experience comes regarding the production engineering (designing things that are easily built so you save time in the factory) and also knowing where to save. People will assume that you save in the circuitry but sometimes the savings come from the color of the handbook, the quality of the package, etc. Unfortunately when you deal with people that don't know about engineering, they don't see this last and they always ask to make the circuit cheaper, then they complain that their customers think their product is cheap
but let's say than, in general with a few exceptions, you get what you pay for,
a lot, there are many misconceptions out there but it is difficult to change them without coming out like a crazy person, an annoying pedantic know-it-all or the likes, more when people have no interest in kowing why they may not be right. I'm sure you have read many times that some people come and try to explain some misconceptions and they are plainly dismissed.
I don't know, but for example assuming that cathode biasing amplifier are Class-A, or 'pure class A', pretty much anything where the 'impedance' word is included, then things like the JVM output transformers are worse than the JCM800 when they actually are the same transformer but mounted sideways..
Not related to tube amps, but people calling a vibrato "tremolo", or even worse tremelo, are wrong. Now go out and tell them
Luckily it is not extreme as in the Hi-Fi industry hmmm, that's difficult to answer. I guess every engineer, or designers but without enigneering background, designing circuits have their own way of coming with a circuit that does a certain function. Some are better, some are worse for the application but the balance can be tilted to either side regarding the details. I guess the main problem is when people don't have 'design vocabulary' or are just closed to learn new things. It is probably fear to the unkown or whatever so maybe those people find my opinions unique, but luckily I haven't worked with many people like that. Mostly, engineers would like to learn new vocabulary and expand their knowledge, at least people with engineering mindset.
Again, I don't know... for example when working on the way I wanted the JVM footswitch to operate I was plainly and simple told "that can't be done" or when comes to pcb design, the way components should be laid out or what track thicknesses to use were found quite unique 17 years ago but that was mostly due to people not knowing the difference between volts and amperes...
So in short, no, I don't think I'm opinonated enough to be found too unique
Life Eats Life
Shredder
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Hello Santiago, I hope this finds you well.
My question for you is:
Do you think changing out the transformers and installing a choke to all Mercury Magnetics
would improve the amplifier from the stock transformers?
Also, which 34’s do you think work best in the power section?
How about fat bottle 6ca7’s?
Thank you for your time!
Pertaining to the beast 410H.
My question for you is:
Do you think changing out the transformers and installing a choke to all Mercury Magnetics
would improve the amplifier from the stock transformers?
Also, which 34’s do you think work best in the power section?
How about fat bottle 6ca7’s?
Thank you for your time!
Pertaining to the beast 410H.
Last edited:
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Hi there, the quick answer is no, you won't notice much. You may try the choke if you are inclined to modify something but I wouldn't change the transformers unless you have problems with them. The change in tone replacing the mains transformer with one designed for the amp (with the same voltages) won't accomplish anything, changing the output transformer may have some subtle differences but for the cost of changing all that I'd rather change pickups, speakers... I'd go for the 'feedback mod' rather than even considering to change the OT.
The 'best' modern EL34s were the old Svetlana, the winged C ones, but they don't make them anymore and since then it has been a bit of hit and miss. I'd probably go for JJs myself but I've also tried and used for quite some time the EHs.
I have pretty much zero experience with 6CA7s but not much to choose from, isn't it either Shuguang or PSVane nowadays?
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I'm sure it is highly unlikely, but on the JVM would it be possible to replace the IR native to the line out with different one somehow?
Life Eats Life
Shredder
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Wow!!
EVH. fan and no experience with 6ca7’s?
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Hi!, there is not such thing as IRs in the JVM. The emulated circuit is all done in hardware. Don't forget that it was pretty much designed in 2005-2006... what could be done is to bypass it and plug the line-out into an external IR processor so you could still use the 'silent recording' feature.
If a balanced output isn't a must then you can always connect the external IR processor to the PA send output on the back, both the line-out and the PA send are pre-master anyway
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haha, yeah you know, the shoemaker's son always goes barefoot...
I tested some long ago, probably when they were starting to put that tube back into production. I remember them being quite harsh but I haven't experimented much with them since back then and also don't want to come out and say "I found them harsh" when my experience has been so limited.
My "VH trials / butchering" direction has been more into getting that sort of tone at very low volumes, without having to rely in a cranked 100W tube amp.
Life Eats Life
Shredder
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To add to your opening words,
-be mindful of squeezing your feet into shoes that don’t fit.. just for the comfort of taking them off.
I am not an engineer but greatly enjoy sitting down with the ones I have and getting in real deep with them.
I am a living hypothesis.
Meaning I will collect every bit of information I can find and put it to the acid test, completely taking machines apart and going against the grain with
passion & conviction to find or create the missing pieces of the puzzle,creating things never heard before.
-stay clear of factoids., tone is not subjective,
it’s objective.
It HAS to be true and tried!!,
with my own hands & brain chemistry.
I challenge engineers brains and sift & sort through their brain plasticity..engineers are living computers.
You know why EVH was so rad?
-He created his own tools-
A master of his craft.
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I guess the background on my 'shoemaking' phrase is that when you spend every day working 8-10h in designing amps, sometimes even over the weekend, the last thing you feel like in your free time is to test different tubes . I did check that the tubes work and are safe, even the company would write that it may be unsafe blah blah, but I didn't go into details or nuances about how they sound.
. I did check that the tubes work and are safe, even the company would write that it may be unsafe blah blah, but I didn't go into details or nuances about how they sound.
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This is a lazy JVM question as I could probably figure it out myself with minimal experimentation but -
Would running the fx loop mix dimed/very high present an issue with balancing the volume of the two channels (set up for clean and high gain)?
I’ve been using the 210h for every show since I got it a few months Ago but balancing the volume of your be two channels has been proving an issue. Even when I have channel two set significantly higher theres still been a major volume drop when switching. At practice I swapped to another amp at practice today and brought the JVM home from my drummers and noticed right away without my pedalboard that without turning the mix down there’s no volume at all without the fx loop pedals connected (board is at my drummers house)
I’m starting to suspect that this may be the cause of the issue since I’ve been maxing the mix knob to date
Does that sound logical?
Would running the fx loop mix dimed/very high present an issue with balancing the volume of the two channels (set up for clean and high gain)?
I’ve been using the 210h for every show since I got it a few months Ago but balancing the volume of your be two channels has been proving an issue. Even when I have channel two set significantly higher theres still been a major volume drop when switching. At practice I swapped to another amp at practice today and brought the JVM home from my drummers and noticed right away without my pedalboard that without turning the mix down there’s no volume at all without the fx loop pedals connected (board is at my drummers house)
I’m starting to suspect that this may be the cause of the issue since I’ve been maxing the mix knob to date
Does that sound logical?
Bruce
Shredder
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Thanks for taking the time to answer questions! Hopefully you can answer or at least speculate on:
Given the ever growing product market of seemingly great sounding modded Marshall circuits, why wouldn’t Marshall offer custom shop services to get you closer to these kinds of amps? Who would know better how to mod a Marshall than Marshall themselves?
Given the ever growing product market of seemingly great sounding modded Marshall circuits, why wouldn’t Marshall offer custom shop services to get you closer to these kinds of amps? Who would know better how to mod a Marshall than Marshall themselves?
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ok, the way I'd approach this is to set up the Clean channel the way you like it and then balance the OD channel against it.
If you are using pedals in the loop, or any series effect, then the MIX should be set to 100% (or almost 100% to compensate for a slight volume drop). The MIX control is already a bit anachronic in the sense that was intended for use with "old" processors that were somehow noisy. The idea is that the processor (for example a Delay, Chorus...) only outputs the effected signal and the MIX control adds the direct one. That way you keep the direct signal inside the amp.
The MIX itself won't really change the volume, it is designed to keep a rather constant mix of direct and effect signal
Not sure I have fully understood the issue, feel free to insist if I was rambling :)
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custom shop... I'll answer in general as it is something that probably affects everybody. I see few issues, one is that modifying amplifiers is quite of a personal thing, I could imagine that companies could offer some sort of 'pre-approved modifications menu' that don't void the warranty but that means they should invest time and money into developing those mods. Probably companies just prefer to spend that time into something more productive (or that hey consider more productive) plus there may be some logistic issues. What I mean is, would an official Technical Service be able to do the modifications, would you need to send the amp back to the UK?...
Then there is a more serious issue to be taken into account which relates to safety and EMC (radio emissions). When an amplifier is put in the market legally, it means it has passed some safety and electromagnetic compatibility tests. Would those modifications make the amplifier unsafe or non-compliant?. That's again more risks and money that a company wouldn't like to take and also why it is so easy to offer cosmetically-modified products but keeping the electronics the same.
I guess the short answer is that they just 'can't be bothered with that', perhaps smaller companies can have a bit of a more personal relationship with the customer and offer some sort of personalization but there are some grey areas regarding liabilities, responsibilities and so on...
Bruce
Shredder
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Great answer thanks
headcrash
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Santiago, would you mind giving us some insight in which processes of "amp development" you were involved at Marshall?
I mean, apart from developing, drawing and tinkering with circuits, would you make decisions on component choices, design, form factor and so on of the amps?
Would you CAD-design the chassis and/or headshell (well, what's to newly or re-design with a Marshall headshell at all... :-) ?
What about modern standards and rules regarding safety, ROHS and stuff? Was that something you were responsible of, or do/did Marshall have exerts on these matters?
Thanks a lot!
I mean, apart from developing, drawing and tinkering with circuits, would you make decisions on component choices, design, form factor and so on of the amps?
Would you CAD-design the chassis and/or headshell (well, what's to newly or re-design with a Marshall headshell at all... :-) ?
What about modern standards and rules regarding safety, ROHS and stuff? Was that something you were responsible of, or do/did Marshall have exerts on these matters?
Thanks a lot!
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Hi, the short answer is yes
Let's say the the involvement evolved over the years, not only in Marshall but also in Behringer and some other companies I've been working with. In the case of M, I was initially hired as an electronics engineer to design pretty much what I was asked for. Those designs usually require being compliant with safety, EMC, manufacturability, etc. What I mean is that designing the sound of an amp is perhaps 30% of the total process. The point is that actually what's the use of a certain circuit if isn't legal, can't be sold or can't even be manufactured.
I think this is one of the main reasons why engineers or technicians become quickly disillusioned when working in electronics development, perhaps it is easier to understand for engineers with a proper training/university background but otherwise it is hard sometimes. Just imagine you go and work in a certain company and you end spending days or weeks dealing with those issues. Not only that but also everything related to manufacturability can be boring and frustrating. Again, just imagine yourself dealing with part numbers, suppliers, assembly issues, etc. etc. but the amp sounds great!
As time passed, I started to participate more in the product design. Sometimes I brought in some ideas, sometimes I have designed the concept including panel layouts and silkscreen. There was not a pattern but what I haven't done myself is the mechanical design. Actually the mechanical design of pretty much all of the amps I have designed were done by a person called Matthew, a very experienced guy with many years in the MI industry and 100s of products out there. Mechanical design isn't only making a box with 4 planks of wood but also deciding plastic injection gates, pressures, knowing bending radiuses, tooling capabilities, packaging and so on. It is a complete art in itself. Of course one could just go to Fusion 360 and design an amplifier cabinet but when one starts requiring that the cabinet needs to cost less than x amount, weight less than x kg, produce just a limit amount of material scrap and stand a fall of 1m with a 25kg amp+speaker inside then you need to know mechanical engineering.
Once I became the Technical Director I was more and more involved with the legal part of the job too, namely safety and electromagnetic compatibility. Sadly this is not something that most people like nor is taught out there so there is a lot of learning-by-doing. The standards with all the requirements are beyond tedious and difficult to read so it ends being something that one learns pretty much by doing, visiting test laboratories, failing many times, trying again and so on. There was a small team of people dealing mostly with paperwork, logistics and all those sort of requirements (there are a LOT of papers to fill and have ready to legally put a product in the market all over the world) but on the technical side it was pretty much myself. Not that I consider myself at all an expert in that field but I have my fair share of experience dealing with those requirements.
RoSH isn't that difficult to deal with and nowadays it is not easy to find non-RoSH parts unless old stock and so on. In general pretty much you just ask the supplier to give you compliant parts, but there are quite a lot of other environmental requirements that can be again tedious. Probably they involve more people in production (for example what type of glue you can use) but as a designer it helps if one is at least aware of them. In smaller companies, yes, one would expect the designer to know 'everything'
And nowadays, working on my own, quite a few of the projects I get from companies in the MI industry are to actually help with safety and EMC issues that they face when sending the products for verification. If I design the product I try to design the safety and EMC requirements from the very beginning, not that that guarantees a full compliance but I'm usually quite close haha (patting my own back here
), then there is always a bit of an issue here and there but if you have prepared the design you can be ready with just a few part value adjustments, otherwise it can get complicated and require a major redesign.hope it wasn't too boring and answered some of the questions!
headcrash
Groupie
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Thanks Santiago, for the insight!
For me it wasn't boring at all, since this answered my questions :)
I'm an electrical engineer as well, and we are about similar age, I guess (was born in 1975). So we've kind of witnessed the "history of development" of rather complex tube amps also from a rather technical point of view.
For my 6-months diploma internship I worked at Stamer Musikanlagen, back in 1998/99.
Stamer was and - to my knowledge - still is the manufacturing company for, or behind the brands Hughes & Kettner, HK Audio, among a few others.
They already must've been quite ahead in the mid-90s, for a still rather young company then. AFAIR, they used soldering and population automation, when I was there. Which of course is a consequence of the quantities of units you want to manufacture profitably, in a given period of time.
Also I vaguely remember a copper cladded EMC testing lab...
However, in the mid 90s suddenly we had 3 or 4 channel switchers, like the Diezel VH-4, ENGL Savage 120, or, well, Hughes& Kettner Triamp Mk I, (just to name a few). Apart from "simply" getting such an amp to work and sound good, all other fields you mentioned above, must already have been quite challenging, even back then.
For me as a hobbyist amp builder, who doesn't sell his amps or services, it's all about getting an amp to work and sound good, and that I or others won't get hurt, when it is connected to power.
I can barely estimate how much time and effort has to be put in a product to meet as many worldwide standards as possible.
I wonder how smaller companies like, for example Diezel do this, they're only 4 folks (!). In the end, it must be - like you said - "just" learning by doing (and allowing to fail, which is another meaning of "learning"
).
For me it wasn't boring at all, since this answered my questions :)
I'm an electrical engineer as well, and we are about similar age, I guess (was born in 1975). So we've kind of witnessed the "history of development" of rather complex tube amps also from a rather technical point of view.
For my 6-months diploma internship I worked at Stamer Musikanlagen, back in 1998/99.
Stamer was and - to my knowledge - still is the manufacturing company for, or behind the brands Hughes & Kettner, HK Audio, among a few others.
They already must've been quite ahead in the mid-90s, for a still rather young company then. AFAIR, they used soldering and population automation, when I was there. Which of course is a consequence of the quantities of units you want to manufacture profitably, in a given period of time.
Also I vaguely remember a copper cladded EMC testing lab...
However, in the mid 90s suddenly we had 3 or 4 channel switchers, like the Diezel VH-4, ENGL Savage 120, or, well, Hughes& Kettner Triamp Mk I, (just to name a few). Apart from "simply" getting such an amp to work and sound good, all other fields you mentioned above, must already have been quite challenging, even back then.
For me as a hobbyist amp builder, who doesn't sell his amps or services, it's all about getting an amp to work and sound good, and that I or others won't get hurt, when it is connected to power.
I can barely estimate how much time and effort has to be put in a product to meet as many worldwide standards as possible.
I wonder how smaller companies like, for example Diezel do this, they're only 4 folks (!). In the end, it must be - like you said - "just" learning by doing (and allowing to fail, which is another meaning of "learning"
).