Do modern guitar amp PCBs still look like they were designed in the 1980's?

[b_force]

Have been in this field for many years.

It's absolutely NOT about lack of 'competition and innovation'.
The competition is very strong in the music industry.
It's is mostly just about marketing.

Although, things are shifting quite a lot lately, for most guitar players, the better amp is still hard-wired and all tube/valve.
From a technical point of view that's obviously a little bizarre of course (much more noise, more expensive to make, more defects and repairs etc).
Besides there are some main (well known) big brands, that just like to stay 'old fashioned'.
I think mainly because they don't need to spend money into research and development and don't have to run the risk of developing a new complete failure.
Keep in mind that naturally most companies don't want to risk to much, and therefore like to close up the market as much as possible.
In fact, the guitar itself has barely evolved from the last 50-100 years.

But like I said, the market is shifting.
5-10 years back 'digital effects and amplifiers' were a complete taboo.
Nowadays, every brand has his own set of digital effect pedals, loop-pedals and there are even a lot of new smaller guitar amplifiers.
I talk to retailers and shop owners on a regular basis and they all say that people simply don't want a big heavy 50-100W all tube amplifier anymore.
To much hassle, to expensive, to many problems with repairs etc.
You can even find a ton of reviews on youtube that are actually very positive about all the new innovations.
Even in blind tests it is pretty much impossible to hear differences.

One of the most well known innovative brands is Line 6, but also Vox has some new products, as well as Yamaha and Blackstar.
Although Line 6 is only the one who is serving the high-end market.
If you want state of the art, Kemper is pretty lonely at the top.
Also every (known) brand has his small little series of transistor/digital effects based amplifiers

Anyway, the shifting is actually so big (and all of a sudden) that I sometimes wonder if they are trying to push valves/tubes obsolete in a couple of years
It wouldn't surprise me, because the efficiency of tube amplifiers is pretty bad, plus they need a lot of copper (= transformers).
One for the mains, one as a choke and one for the output transformer.
As far as I know, there is not one brand that is using a SMPS or similar.
Which also doesn't go well with all the (new) regulations and rules in electronics, safety, PFC, power supplies etc.

So, to summarize; yes there are enough brand/products that use 'nicely' made dual or even 4 layer PCBs.
But most of it is still old fashioned, because it simply sells better (because people think it is better)

[b_force]

I've had a little bit of professional involvement here.

From what I understand, customers for this type of product have expectations regarding the aesthetics of a PCB, and a subconscious expectation that if it looks "good", then it'll sound good too.

"Good", in this context, meaning "in line with the customer's expectations of how this type of equipment should look".

There's no science here, though. A small PCB made with surface mount components and a ground plane will pick up less noise than one made with through-hole parts on a single sided board. In objective performance terms, it's simply better, but that doesn't mean it's what the customer actually wants.

Subjective neatness, and similarity to other products with a good reputation, are really important in this highly conservative part of the industry.

This also works for the whole hifi market.
I have been studying it for many years now, and companies put a lot of money, energy and resources in getting better THD+N results and other theoretical specs  .
Why? Well, it is easy stuff to sell to the unknown and ignorant customer.
In fact, the stories are so deeply penetrated that even a lot of (very highly respected) engineers believe in these fairy tails and marketing BS.
On the priority list, these things are aaaaaallll the way at the bottom.

But once a good gossip marketing story has settled, and big well known respected companies use them, it is VERY difficult to get rid of them.
(impossible)

[e100]

I did a Google search for "guitar amp DSP" naively thinking it would turn up a bunch of results, but it turned up almost nothing until I stumbled upon the term "modeling amp" which is an amp containing a DSP that allows it to emulate the sound of other types of amps. So it seems than even the word 'digital' is taboo in the guitar world.

[e100]

Have been in this field for many years.

It's absolutely NOT about lack of 'competition and innovation'.
The competition is very strong in the music industry.
It's is mostly just about marketing.

....

So, to summarize; yes there are enough brand/products that use 'nicely' made dual or even 4 layer PCBs.
But most of it is still old fashioned, because it simply sells better (because people think it is better)

So the marketers have been promoting the old designs for for the last 20+ years in order to protect their profit margins?
Wouldn't be the first time that music industry has dragged it's feet in the face of new technology.
I suppose it's the power of the cartel controlling the market, making sure any new players "don't rock the boat, don't tip the boat over", so to speak.

[e100]

Found a picture of a modeling amp interior complete with switch mode power supply.
From http://www.kramerforum.com/george/amps.html

[b_force]

Have been in this field for many years.

It's absolutely NOT about lack of 'competition and innovation'.
The competition is very strong in the music industry.
It's is mostly just about marketing.

....

So, to summarize; yes there are enough brand/products that use 'nicely' made dual or even 4 layer PCBs.
But most of it is still old fashioned, because it simply sells better (because people think it is better)

So the marketers have been promoting the old designs for for the last 20+ years in order to protect their profit margins?
Wouldn't be the first time that music industry has dragged it's feet in the face of new technology.
I suppose it's the power of the cartel controlling the market, making sure any new players "don't rock the boat, don't tip the boat over", so to speak.

Well, of course it's a bit of an chicken - egg story.
But does this sounds new to you? I mean in all markets companies make you believe in fancy stories.
The whole music industry is one big niche filled with voodoo for example.
I can give you thousands of products that are being sold for $$$, are badly designed and are praised by many (even technical engineers).
This is just called marketing. Once you get the hang of it, open your mind with a skeptic point of view, you will laugh your pants off.
Dive in the world of test equipment and it is the same story.

Digital is indeed a bad name in the music industry.
For the same reason as Class-D amplifiers had a bad name (that has already changed)
A few companies tried it 20 odd years ago, but the world wasn't ready yet (also because technology wasn't far enough).
But that's no different for tablets for example, which you could also find 20 years ago.
Microwaves boomed 20 years later after they were invented.
Sure the technology wasn't right for it, but people also find it a strange idea to use these products.

edit:
Maybe to explain something more about marketing.
I worked for a company developing big high power Class-D power amplifiers and DSP boards integrated with active loudspeakers.
One of the problems we had, is how to market our products. aka; what makes our products different and better than other competitors?
I am talking about big players on the market (sales over more than hundreds of thousands to millions a year) vs a small company (in tens of thousand).
Just saying that your product simply 'sounds better' isn't enough. Especially if you ALSO use a DSP and Class-D amplifiers and competing against big respected companies (even if they are doing it wrong for years)

For that reasons the company was still making a lot of 'analog-filters'. Simply because customers (and oddly enough some engineers) believed in the fact analog is better (less noisy etc etc) than digital.

[frozenfrogz]

Digital is not really a taboo, but it heavily depends on what you genre of music you are looking at.
There are two major competitors in the field of DSP / modeling amp / virtual amp setup. One is Fractal Audio with the Axe FX line and the other one Kemper with their Profiling Amp.
Line6 (POD, Helix,...) are a bit on the cheap side and though they improved in tone quality, I would classify them as second league.

There are some Hybrids, like the Peavey Vypyr series and Hughes&Kettner Coreblade / Switchblade.

If you need versatility in a band that travels a lot, Fractal and Kemper are a good solution. You can even go the full mile and just pack your sound setup on USB drive with you. On stage, you get gear from the distributor, drop your sound setup in and are ready to go (H&K Coreblade also can do that).

Most musicians are gearfreaks – as some of you can relate to – so you might own a bunch of amps, effect pedals and what not. In the past five to ten years, guitar tube amps have lived through a revival, mainly in the so called "High Gain" sector. You can get a lot of boutique amps and of course the big manufacturers try to get their share.
Basically, you are correct: It is the 80s all over again. If you want to be »Metal« you want to play a heavy, oversized head amplifier with two 4x12’’ speaker cabinets.
From a sound studio perspective I can tell you: DSP has come a long way, but in direct comparison to the "real deal" you don’t get the same response from a modeling amp compared to a good tube preamp section.

Now a little for your call to old-school PCBs: There is a lot of space inside a typical tube amp housing. So why go all fancy with four-layer high density boards, when you really don’t need it, plus you are dealing with big fat parts anyway? (caps, tubes, transformers, high power resistors,...) From a modding perspective it is even greater value. You don’t have to fuck around with dense integration, but you can simply work on clean subsections. Input section here, tonestack over there, some inverting magic on that end, FX loop that way, power amp section here and power supply on that board...

[b_force]

Digital is not really a taboo, but it heavily depends on what you genre of music you are looking at.
There are two major competitors in the field of DSP / modeling amp / virtual amp setup. One is Fractal Audio with the Axe FX line and the other one Kemper with their Profiling Amp.
Line6 (POD, Helix,...) are a bit on the cheap side and though they improved in tone quality, I would classify them as second league.

There are some Hybrids, like the Peavey Vypyr series and Hughes&Kettner Coreblade / Switchblade.

If you need versatility in a band that travels a lot, Fractal and Kemper are a good solution. You can even go the full mile and just pack your sound setup on USB drive with you. On stage, you get gear from the distributor, drop your sound setup in and are ready to go (H&K Coreblade also can do that).

Most musicians are gearfreaks – as some of you can relate to – so you might own a bunch of amps, effect pedals and what not. In the past five to ten years, guitar tube amps have lived through a revival, mainly in the so called "High Gain" sector. You can get a lot of boutique amps and of course the big manufacturers try to get their share.
Basically, you are correct: It is the 80s all over again. If you want to be »Metal« you want to play a heavy, oversized head amplifier with two 4x12’’ speaker cabinets.
From a sound studio perspective I can tell you: DSP has come a long way, but in direct comparison to the "real deal" you don’t get the same response from a modeling amp compared to a good tube preamp section.

Now a little for your call to old-school PCBs: There is a lot of space inside a typical tube amp housing. So why go all fancy with four-layer high density boards, when you really don’t need it, plus you are dealing with big fat parts anyway? (caps, tubes, transformers, high power resistors,...) From a modding perspective it is even greater value. You don’t have to fuck around with dense integration, but you can simply work on clean subsections. Input section here, tonestack over there, some inverting magic on that end, FX loop that way, power amp section here and power supply on that board...

Yes, this is in line with my research as I mentioned above.

Using DSP's is also a little bit digging your own grave.
I mean, as soon people know that you can make EVERY amp with the same design (which can easily be done with DSPs), why would they even buy new equipment? In fact, with impulse responses and some eqing you can make your guitar sound like any guitar you like.
So companies NEED to make up a story to sell new stuff, therefor they don't mind keeping up the voodoo stories.

This has been the issue for a very long time for light bulbs.
For that reasons companies (like for televisions) obviously design with parts with underrated specs.

[free_electron]

According to my findings, it is not recommended to use printed circuits boards with tubes for the following reasons:

- strong heating of the solders of the socket of the tubes and of the power resistors, which causes bad solders. The situation has worsened since the use of lead-free solder.

- high voltages in the circuits, especially in the output tubes .... there is a high risk of arcing and carbonization of the printed circuit.

The use of printed circuits boards causes a great reduction in the reliability of the amplifiers.

tubes ? it is 2017 ! time to bury that 'glass with scrap metal in it'.

[Cerebus]

No. Never treat your customers like idiots.

Unless they are drummers. 

Cue long thread of drummer jokes...

[drussell]

Some people who are not in the industry do not seem to realize that the whole apparatus from the guitar string to the pickup to the way the particular guitar body and neck vibrates to the cabling and any in-line effects pedals to the pre-amp stage to the tone controls to the output amplifier to the speakers and the cabinet they are in... THAT WHOLE THING... becomes the "instrument". 

The whole package defines what kind of "sound" the player gets, so, YES all of these things matter!!  This includes any distortion, feedback, microphonics, etc. that, while they would generally be highly undesirable in a Hi-Fi amplifier, are critical to achieving the "sound" that particular musician wants and is probably "known for".

There is a damn good reason that people will spend a small fortune keeping what seems like some old clunker to the casual observer running as they want it regardless of if it is "correct" or even anywhere near what the factory originally intended, etc. 

It is their sound!

[drussell]

Unless they are drummers. 

All the drummers ever seem to say is, "I need more kick drum in my monitor!" 

[drussell]

tubes ? it is 2017 ! time to bury that 'glass with scrap metal in it'.

Spoken like a true non-believer! 

Are you qualified to comment on this?   Do you even own any tube gear?   

You stick to your crunchy, crufty, crudular solid-state gear, and I'll happily plod along listening to my music on my Dynaco Mk. VI monoblocks with the 8417s playing through good home-made speakers, thank you very much! 

The sound can be absolutely euphoric!

(Though, I must admit, my old Bryston 4B is pretty good too...  For a SS amp!  The warranty on that ol' bird is even finally well past expired, despite the fact that Bryston retroactively increased the warranty duration to 20 years from the original 15 years.)

[N2IXK]

You stick to your crunchy, crufty, crudular solid-state gear, and I'll happily plod along listening to my music on my Dynaco Mk. VI monoblocks with the 8417s playing through good home-made speakers, thank you very much! 

The sound can be absolutely euphoric!

The only question is where are you finding 8417 tubes these days at a price that doesn't call for a second mortgage?  The Russians and Chinese haven't been able to produce those today, despite several attempts.

[e100]

No. Never treat your customers like idiots.

Well I just found a modeling amp (aka DSP powered amp) that has valves to give it that authentic sound that a DSP simply cannot provide (apparently).
https://www.sweetwater.com/store/detail/AV30Combo

[LaserSteve]

At our church we had a guitarist who insisted that if the plate in the tube is not glowing red, he did get  "his" correct sound. So one day I snuck in early and replaced the preamp and power amp tubes on his stupid little 100$ box. The power tube was so gassy you could see the plasma in room light. There was a master gain / bias pot inside the amp, and that got set down to something more reasonable. Both old tubes were immediately sent to fire bottle Heaven using a humane hammer.

That was the day he learned he could play classical guitar and sound much, much better. The smile on his face grew the more he played that day.

 It's also the day we sent him to ear specialist  to save what was left of his hearing.

Moral of the story, since their teens, musicians are often  taught this audiophool lore about what they should do. They really didn't want me to put wall  treatments and Bass corner damping in the band area. Now that they can hear each other, and are not getting  lobes from the monitors , they won't play without the adsorber panels, and are asking for more.

It comes down to education, and having a congregation that backs me when I make changes. Our measured  C weighted sound level is down 20 Db at the back of the church from when I started, our voice intelligibility  is way up, and we get compliments on how the band sounds now.

We simply didn't tell them when the DSP amps  went in and the snakes were replaced with 30 pairs of double shielded wire under the floor. Our noise floor went down to below what I can measure, and no more 60 Hz hum. Getting all the sound and video gear on the same line phase helped too. You can't "buck" hum when it's 120' out of phase.


But some times I still feel  I will need to open the "Stalog 440   "  re-education camp, to remove the folklore and marketing BS I have to deal with ofhim.

But you can reform them with patience and a big enough stick.

Steve

[b_force]

Some people who are not in the industry do not seem to realize that the whole apparatus from the guitar string to the pickup to the way the particular guitar body and neck vibrates to the cabling and any in-line effects pedals to the pre-amp stage to the tone controls to the output amplifier to the speakers and the cabinet they are in... THAT WHOLE THING... becomes the "instrument". 

The whole package defines what kind of "sound" the player gets, so, YES all of these things matter!!  This includes any distortion, feedback, microphonics, etc. that, while they would generally be highly undesirable in a Hi-Fi amplifier, are critical to achieving the "sound" that particular musician wants and is probably "known for".

There is a damn good reason that people will spend a small fortune keeping what seems like some old clunker to the casual observer running as they want it regardless of if it is "correct" or even anywhere near what the factory originally intended, etc. 

It is their sound!

No, it's all about THEIR feeling.

You can make a 100% identical sounding and technical measuring amp with just a DSP and a (simple) class-d output stage.
In fact, technically it's not that difficult to cancel/correct all these links in the chain and even the most advanced and experienced professionals in the field are unable to hear the difference.
There is more than enough literature about this.

Most technical people forget something and that is that most people (inlc engineers) don't choice rationally.
So if things don't feel right, it simply doesn't work for them.
This whole phenomenon is called placebo effect.
We simply hear, feel, see, taste and believe things that are not there.
Perfect grey area for the marketing department to make up some juicy stories.

At our church we had a guitarist who insisted that if the plate in the tube is not glowing red, he did get  "his" correct sound. So one day I snuck in early and replaced the preamp and power amp tubes on his stupid little 100$ box. The power tube was so gassy you could see the plasma in room light. There was a master gain / bias pot inside the amp, and that got set down to something more reasonable. Both old tubes were immediately sent to fire bottle Heaven using a humane hammer.

That was the day he learned he could play classical guitar and sound much, much better. The smile on his face grew the more he played that day.

 It's also the day we sent him to ear specialist  to save what was left of his hearing.

Moral of the story, since their teens, musicians are often  taught this audiophool lore about what they should do. They really didn't want me to put wall  treatments and Bass corner damping in the band area. Now that they can hear each other, and are not getting  lobes from the monitors , they won't play without the adsorber panels, and are asking for more.

It comes down to education, and having a congregation that backs me when I make changes. Our measured  C weighted sound level is down 20 Db at the back of the church from when I started, our voice intelligibility  is way up, and we get compliments on how the band sounds now.

We simply didn't tell them when the DSP amps  went in and the snakes were replaced with 30 pairs of double shielded wire under the floor. Our noise floor went down to below what I can measure, and no more 60 Hz hum. Getting all the sound and video gear on the same line phase helped too. You can't "buck" hum when it's 120' out of phase.


But some times I still feel  I will need to open the "Stalog 440   "  re-education camp, to remove the folklore and marketing BS I have to deal with ofhim.

But you can reform them with patience and a big enough stick.

Steve

This is exactly what I was talking about.
As soon as people don't see it anymore, things turn out very different.
That's why double blind tests are so important.

Once read a paper about a double blind test between a very expensive Stradivarius and a decent priced Yamaha violin.
Guess which one people liked better?

Like I said before, the problem is when even engineers don't know what is real anymore.
And yes, I have come across many 'guru's' who now simply believe in their own marketing BS crap.

[Zero999]

Digital is not really a taboo, but it heavily depends on what you genre of music you are looking at.

Let me guess. If you're into electronic dance, contemporary R&B, hip-hop etc. then you're more likely to be a digital lover, than someone who likes blues, country, rock etc.

Then they're the music snobs also annoy me. They'll only listen to a few genres or hate anything too pop because it's not real music.

Personally I don't care. I can be picky but I listen to various types of music.

As far as amplifiers are concerned: if modern technology can emulate old valve amps then great but I see no reason not to build and use them because old things are cool. Some people still enjoy building and using steam engines, even though they're well and truly obsolete.

[danmcb]

A year or two back, I designed a nice analogue preamp/compressor/overdrive/distortion box that I intended to be a bit better than the usual diecast box with a 9V supply and so on. I spent quite some time on it - a nice optical compressor, silent switching, and running internally from +/-15V so it has much more headroom and signal/noise than most of these things. Also a decent quality properly designed metal case (which cost me a small fortune in low quantity.) I went through quite a few prototype/test cycles with various musician friends (I know a bunch as I also play a lot).

I took it to the local guitar boutique store, and showed it to the guys there. The Axeman-in-chief looked at it sceptically and asked why it was so big, used a funny power supply, etc. After telling me how there was so much on the market and really no need for anything more, he decided to actually try it out.

He plugged it into a nice looking Fender valve amp, played for ten seconds and then said to me "I see what you mean". (I must admit - it did sound good - and he could play.)

Ten minutes later, he went to his boss, pointed at my box, and said "this thing is dynamite" (or words to that effect). So they took one on sale or return.

I went back a few weeks later, it was in a glass case, next to a huge, garish pink and blue thing with more lights than Blackpool 9my box is simple black and white - has some nice LEDs for level setting, compression and so on - but looks pretty dark with power off). I asked then how it was going. They said "disappointing - noone asks to try it".

I didn't ask them if they actually suggested it or actively tried to sell it to potential customers. I think I know the answer.

I have sold a few - one is being used in the live rig of one of the top session players here (we made a deal  where I discounted and he made me a great video), another is in one of the top studios (apparently it was used the first weekend they had it - by a guy that produced some Blur albums. On bass.)

It's all about marketing, as others have said. Most people will buy what looks cool or what a magazine/website tells them is cool. Unless a thing sounds *really* bad (so bad that you'd actually have to try to get it that way) very many will not even hear any difference.

But - the really good ones - *do* know the difference, and hear it. But that is about 0.2% of people. Most of the market is composed of amateur or semi-amateur musicians who very often put up with pretty poor quality, and don't notice it.

[james_s]

Most fell into the Nigel Tuffnell 'it goes to eleven' realm.

Hah! That's a great movie, haven't seen it in a while.

[Jr460]

Yes there are many idiots on stage that have all kinds of strange ideas about amps and sound.

Me, I 've either played in a band (keys, bass, vocals) or ran sound for one of the past 40 years. 

One guitarist I worked with had this 100 watt Fender transistor amp.  I sounded OK if you got the thing turned up to about 7 or 8.   But in small clubs 2 or 2.5 was killing everyone.  He never got the idea to get something smaller and then you can crank that and let the PA fill the room.  He would read all the wrong things....   "Hey, we have that festival next week, I've heard you should use, or use more compression when playing outside.  What do you think?"   I told him he was nuts, stop reading the 14 year old Stratplay452 on some guitar forum and get a sound he likes and let the PA take care of the rest.  He never got it.  Set his amp back by the drummer.  The drummer proceeds to bash the living hell out of the brass to hear himself over that monster amp.  Turn into loudness war.

My keys have been mainly digital, but I have to say it is a lot of fun to play a real B3....   each one has a slightly different personality.

The current PA rig I drag out is a digital board, (not a bear-ringer or smackie), and I love the way it sounds and so does everyone that has heard it and A/D converters.  Speakers, I've done both QSC amps into passive speakers, but recently  all-in-one powered tops and subs that are class D and DSP driven.

The current band I run FOH for, the guitarist used a Line6 amp for a long time and it was OK.  It had some fault where the volume would jump up or down without warning.  He researched it fund it to be a common fault and the only fix is an expensive replacement of the one and only board in it.   A few weeks ago he picked up a small newish Vox tube amp and drove it with a Fender all-in-one pedal board.

Yikes!!!!

Total nightmare.  Sounded like ass.  It just would not do what he wanted when he wanted it.  One the first break, he pulled the Fender  and plugged in a set of foot pedals.   It was much better, but now he was gun shy the rest of the night, paying more attention to his tools than his work.  He had 30 days to return that amp and he did and picked up a 10 watt tube amp instead.

Last weekend was great.  He never sounded so good.  It allowed him to put his effort into playing, not playing with gear.  About the only thing better that I've heard is the wife's guitar into AC30 clone I build for her.  I might be a bit biased.

I'm don't dislike digital, I don't bow down to tubes either, but the current DSPs don't sound the same.  Close, very close, but different.

One other thing to keep in mind.  The older designed amps with point to point wiring and such can take a lot of road abuse.  You would be surprised how much everything gets torn up even with just weekend gigs.

[e100]

Anyway, the shifting is actually so big (and all of a sudden) that I sometimes wonder if they are trying to push valves/tubes obsolete in a couple of years

So the marketing people are actually responding to the consumer demands for lightweight easy to transport gear?
Why now and not 10 years ago?
Has another manufacturer managed to disrupt the market forcing the cartel to move in lock step?

When I started this thread I had no idea we would end up here. It has been a fascinating window into the power of marketing and it's ability to stifle technology for an entire generation.

[WZOLL]

As far as I know the only amp that cant be completely modeled by a DSP is the Deacy amp because of its damaged cone. IMO complex modular analog synths are the only thing that can't be reproduced digitally 100%. Here is the amp in action

[BradC]

I'm don't dislike digital, I don't bow down to tubes either, but the current DSPs don't sound the same.  Close, very close, but different.

This is the thing. I gigged for years with a transistor amp and a variety of "modelers" to give me a Vox AC15 jangle. They did a credible job, but were never quite right. Close though. I was pretty happy with the sound until I did a gig with a borrowed AC15. My problem here is I can't figure out how to express exactly what I want to say, but there is no way in hell the modelers even get close to replicating the "responsiveness" of the real thing. The best way I can describe it is the sound itself is close, but the way the sound changes in response to playing volume. Attack on the string I suppose is the best way of describing it. It's just nowhere near it. It's almost like the amp has more dynamic range, but it'd better be described as characteristic non-linearity that the modelers just don't get right.

I've owned mostly solid state amps since I've been playing and I've used most modelers at least once. I'm a firm believer in technology and the constant improvement it can bring, but I've never found a solid state amp that can get close to the sound of a valve amp if that is the sound you are after. They are all "close but no cigar". And don't get me wrong, having the ability to go from a jangly Vox to a Marshall scream and a Fender clean at the twist of a knob or press of a pedal is fantastic. But there is still a significant difference, and the fact it's so hard to explain and quantify is why none of the modelers are there yet.

It's not Audiophoolery, there is a credible difference in the end to end signal chain when you plug a guitar into a valve amp. Then put an old Echomatic in the chain and see it change again. The non-linear pre-amps and asymmetrical valve biasing leading to an asymmetrical load impedance for the wound pickup combined with the variable capacitance of the various guitar leads. It's a pretty complex chain to try and model.

Remembering that even the wood the speaker box is made out of forms part of the "instrument", and then try and figure out how to model that entire chain.

I love my bulletproof transistor amps and digital modelers, but when you want that special sound that nothing yet replicates, you need warm bottles of almost-vacuum. Nobody has yet perfectly replicated the chaos of non-linearity they present. Maybe it's "personality"

[bibz]

This is a far too nuanced and experience related topic to really go into detail here. The pcb isn't the 'guts' of an amp. It's not the main focus like it is with digital stuff. To me the tubes (different brands sound and react different, pick a single type and spec of transistor for every different project...you can't!) and the transformers will play just as big a role as the circuit. But thats just the high end stuff. Theres plenty of SHARc and whatever based stuff, the AxeFX and particularly the Kemper profiling stuff is VERY deep in technology. It's software stuff would be a very heady read.

But in the flesh, the feel counts more. You can't pick a wife from a datasheet

It's all relative, you can get by with an irig setup and some headphones. Sounds 'ok' at times. Different experience. I use software for practicing, its instant gratification, but it in no way can replicate real gear at real volumes. If you've never felt what its like pushing major air around a big room at your will with a big guitar sound I can't describe it for you