Where does the tone come from in a guitar amplifier ?

[Vivek]

[Elektrojänis]

Didn't watch the video yet, but I'll throw in my quess: Speaker

That guy makes som interesting testing for various things.

[Rob Strand]

One of the best cause and effect breakdowns ever.  He did a fantastic job.

[Vivek]

He beautifully illustrated exactly what RG Keen, Teemu K, other gurus here, Fractal Mimic paper, Yamaha patents, Rockman patents, Peavey patents and others have been saying for a very long time.

[andy-h-h]

Pure gold....  Wampler also did some videos on a similar theme, but nowhere near as detailed.   

[Elektrojänis]

Damn... He tested the amp only, but that was even better than I expected.

His end result is pretty much what the jfet emulations have been going for.

[andy-h-h]

His end result is pretty much what the jfet emulations have been going for.

A thing I've always found a little odd about JFET based preamp emulations is that you end up running the tone stack of one amp (the pedal) into another tone stack (your amp), and without the benefit of the cab / speaker etc.   

[Shoeman]

Very well done. Thanks for sharing.  I liked his comments near the end about forums, etc and peoples perceptions. Reminded me very much of a favorite Black Adder line:
Edmund: So, what you're telling me, Percy, is that something you have never seen is slightly less blue than something else you have never seen.

[Vivek]

Damn... He tested the amp only, but that was even better than I expected.

His end result is pretty much what the jfet emulations have been going for.

I don't feel that the fact that the nonlinear element was a JFET has too much bearing

Meaning that I believe any other nonlinear device would create almost same sound if enveloped by same filters on both sides

[Elektrojänis]

I don't feel that the fact that the nonlinear element was a JFET has too much bearing

Meaning that I believe any other nonlinear device would create almost same sound if enveloped by same filters on both sides

That's how I've thought about it for a long time too. And many of the gurus of this board have been suggesting that probably for several decades. JFETs just make it relatively easy to replicate tube pre-amp stages.

But really cool how on the video he managed to get those tones so close with such hacked together aproach. One of the cloned tones was somewhat darker, but I bet that could be "fixed" with some more tweaking.

[StephenGiles]

Surely much of the tone comes from how a string is plucked and construction of the pickup. I'd wager that it has nothing to do with the wood of the guitar - my DIY SG with a P90 sounds exactly the same as my Les Paul Junior.

[Elektrojänis]

Surely much of the tone comes from how a string is plucked and construction of the pickup. I'd wager that it has nothing to do with the wood of the guitar - my DIY SG with a P90 sounds exactly the same as my Les Paul Junior.

This one was about amps, but the same guy from that video has separate video on guitars. The end result is kind of hilarious.

[r080]

Surely much of the tone comes from how a string is plucked and construction of the pickup. I'd wager that it has nothing to do with the wood of the guitar - my DIY SG with a P90 sounds exactly the same as my Les Paul Junior.

This one was about amps, but the same guy from that video has separate video on guitars. The end result is kind of hilarious.

Link to thread on that one:
https://www.diystompboxes.com/smfforum/index.php?topic=128650.0

[StephenGiles]

And I think the output valves have something to say about too!!!

[anotherjim]

Forum speak "glassy and dark" all at once? I'm with "glassy and hard" - it describes every AC30 I've met, including modern made-in-China examples that don't have the Pentode in the preamp.

[Vivek]

I would love to audit his spice analysis and that analog Amp simulator he shows towards the end, in support of his hypothesis.

I know from experience that it is quite a difficult task to study the interstage frequency response and transient response of a tube amp, and then simultaneously replicate both with existing pedals.

Existing pedals have their own filters and gain stages  built in, so it's not an easy task to use them to match the response of some other amp.


There also seems to be a contradiction. The author seems to claim that the main reason for different amp tones is the exact specifications of multiple EQ and distortion stages inside the Amp. Yet for one Amp, he only measures the total frequency response and distortion at the end of the Amp. However he shows that he could make an analog setup using pedals which replicated the final sound by replicating the interstage EQ and distortion (which were not measured)

[ElectricDruid]

I would love to audit his spice analysis and that analog Amp simulator he shows towards the end, in support of his hypothesis.

I agree, that would be interesting.

I know from experience that it is quite a difficult task to study the interstage frequency response and transient response of a tube amp, and then simultaneously replicate both with existing pedals.

Yes, and while I think his video is very thought-provoking, I'm not sure that I consider proving that you can get one or two sounds to sound the same as "case closed". I can get a ford focus to drive at the same speed as a ferrari in second gear, but it doesn't mean they'll be the same when you really let rip.
That said, I do believe his conclusion - a lot of the stuff people make a big fuss about is small beer, and tone-shaping before and after distortion stages is where the real action is.

Existing pedals have their own filters and gain stages  built in, so it's not an easy task to use them to match the response of some other amp.

Quite! Most pedals are actively striving to impart some "character" of their own, so they also try and shape the frequency response and distortion amounts in specific ways. I know I do when I'm designing something!
For his particular application, he was using basic EQ pedals, and a solid state booster pushed to distortion so that he could get an "uncoloured" distortion, rather than what you'd get from a pedal designed to distort. This is one distortion application where the Tubescreamer is *entirely* the wrong tool for the job!

There also seems to be a contradiction. The author seems to claim that the main reason for different amp tones is the exact specifications of multiple EQ and distortion stages inside the Amp. Yet for one Amp, he only measures the total frequency response and distortion at the end of the Amp. However he shows that he could make an analog setup using pedals which replicated the final sound by replicating the interstage EQ and distortion (which were not measured)

I'm not sure I'd call that a "contradiction". If he managed to get the analog emulation close without having more detailed analysis of what was happening at each stage, he probably just tuned it by ear. That's a reasonable method, if you've got decent ears. Personally, I have terrible ears, and consequently I'd be much more inclined to rely on analysis, but other (more musical) people seem to have that analysis "built in"!

Like others said, the final message for me is that the "amp in a box" quest might well not be pointless! And yeah, if you're going to play through an amp-in-a-box pedal, it doesn't make sense to then screw that up by running it through another tone stack set all over the place - we want a flat response out to the speaker+cabinet (which will provide enough shaping on its own).

[Fancy Lime]

Really important video. Everytime he said "people on the internet", I thought "hey, I'm a people on the internet! I never claimed such nonsense!"   He's preaching to the choir on this here forum but man do "people on the internet" get riled up about amp mojo features on *certain* gear forums. I'm afraid he won't be heard in those circles, though. People who have dropped years' worth of wages on "that one magic amp" don't generally respond well to learning that the reasons why it sounds good are rather banal and easily replicated with half a moca-latte's worth of RadioShack parts and a bit of skill.

[puretube]

"The Tone comes from the fingers" (of the knob-twiddler) ...

[Ell]

Another thought provoking Jim Lill video. So, do all valves basically sound the same, just with different gain? Do all transistors basically sound the same once you've accounted for gain? Do all diodes, once you've accounted for forward voltage?
This does make me tempted to try playing around more with gain stages and eq. Might build a Runoffgroove Eighteen, or at least compare the schematic to the real 1974x