Trying to Understand Preamp vs. Power Tubes and their Emulation

[petemoore]

sounds like the only way to get what I'm looking for is to run it for real (i.e., live at high power with a speaker and so forth), at which point I might as well just simplify things and use a tube anyway.
   Getting a tube to do 'work' is one thing, making the way a tube works 'do what you want it to' is another matter entirely, supertone isn't had by proxy of any 1 particular component or component type. The way an amp sounds is an amalgum of what an amp 'is', if looking for distorting power output tube, the 'stuff' involved in the amalgum seems to start mattering more...power supply, output transformer characteristics, tube qualities to mention a few 'big ones'...then there's the voicing of course.
   There are some pretty decent tube platforms which are relatively speaking 'cheap' and affordable, beefing 'em up seems to be a popular approach to ''premium-tube-performance''.

[DougH]

Look up the MM guitar amp schematics
Some are an IC solid state preamp to IC PI then cascode transistor tube class B or AB(I believe I read it is a class B output I have not worked on a MM to check if this is true) transformer output.

Err, which "MM" do you mean? Google found quite a few differing ones, alas...

Also try a solid state amp like a 10Watt practice amp into a good 2X12, 4X12 etc.

Read MAC's post in this thread.

Quoth mac:

It's the power tube + output transformer duo what many pros like.
Of course it depends on the design, can sound like crap.

Absolutely. I have a keyboard amp (some SS Peavy thing) which sounds great, even on guitar, when run at full volume. I always thought it was just this one amp, and was embarrassed to admit that I like how it sounds, but now I'm convinced that good tone comes from good design, not the specific parts.

What is there to be "embarrassed" about? If it sounds good it is good.

[zambo]

I got a sweet SS peavy transtube. sometimes its fun to layer it with other amps in the studio. pretty distinct sound imho. I like it a lot.No shame.

[DavenPaget]

I got a sweet SS peavy transtube. sometimes its fun to layer it with other amps in the studio. pretty distinct sound imho. I like it a lot.No shame.

I walked into my former school's jam room and found a transtube 50 ... sadly , there were lack of settings , no attentuator , overdrive wasn't working , pot was scratchy .
So my lead guitarist ended up using the VOX VT50 ... And me ? No amps to use . Even two smarvo heads was humming (AC hum) crazily .
CLOSE ENOUGH .

[jafo]

Absolutely. I have a keyboard amp (some SS Peavy thing) which sounds great, even on guitar, when run at full volume. I always thought it was just this one amp, and was embarrassed to admit that I like how it sounds, but now I'm convinced that good tone comes from good design, not the specific parts.

What is there to be "embarrassed" about? If it sounds good it is good.

Agreed, but the ridicule you get from most guitarists can be a bit shaming... you've transgressed against a social norm, albeit an idiotic norm.

[iccaros]

you've transgressed against a social norm

that's called rock and Roll,  if you not transgressing somehow, then your just a poser.. 
Its like ridding motorcycles, if you ride what everyone else likes, then your not riding for love, your doing it for looks..

I play a Les Paul and a Aria Pro that I have modified, and a 62 strat. I have had these guitars for over 20 years, and the fender for 30. I drop D the Les paul before it was cool
it stayed while it was cool, and now that is becoming uncool.. Its still dropped..  if I may line up with trends but I am not there because of them, I stay true to my playing for better or worse..

[petemoore]

   Nothing wrong with something like it, if it is cool. It can only be wned by one owner.
     I take the approach but not the same route as my predecessors : Find stuff that looks and sounds great and use that...try new things and work that the same way, use the equipment you have and love it or find something more appropriate.
   Spec sheets can be your friends too, sometimes a 'sleeper' design can be found that really excels but just doesn't have the fanfare yet to warrant a price jack-up. My experience is that if the specs looks suitable the equipment or component is usable/applicable.
     I got a Mosfet amp I really enjoy playing through also, although it's a lot like a tube amp not cranked, the cleans are super-respectable, and the price was phenomenally attractive...glad I have it.
   Owning a piece for 'a while' is the only way to really get to know it well.

[DavenPaget]

   Nothing wrong with something like it, if it is cool. It can only be wned by one owner.
     I take the approach but not the same route as my predecessors : Find stuff that looks and sounds great and use that...try new things and work that the same way, use the equipment you have and love it or find something more appropriate.
   Spec sheets can be your friends too, sometimes a 'sleeper' design can be found that really excels but just doesn't have the fanfare yet to warrant a price jack-up. My experience is that if the specs looks suitable the equipment or component is usable/applicable.
     I got a Mosfet amp I really enjoy playing through also, although it's a lot like a tube amp not cranked, the cleans are super-respectable, and the price was phenomenally attractive...glad I have it.
   Owning a piece for 'a while' is the only way to really get to know it well.

And what Mosfet amp did you have ? 

[DougH]

Absolutely. I have a keyboard amp (some SS Peavy thing) which sounds great, even on guitar, when run at full volume. I always thought it was just this one amp, and was embarrassed to admit that I like how it sounds, but now I'm convinced that good tone comes from good design, not the specific parts.

What is there to be "embarrassed" about? If it sounds good it is good.

Agreed, but the ridicule you get from most guitarists can be a bit shaming... you've transgressed against a social norm, albeit an idiotic norm.

Let me help you with that.;-)

Most guitarists are idiots. No, really and truly most people in general don't think too hard and just follow the crowd- thinking is too much work. Most musicians you remember did/do their own thing despite what was/is currently popular. And then the funny thing is the crowd starts following that, instead of getting the message that you can do whatever you want if you think for yourself.

People get caught up in "you have to do this or that" but many would be surprised at the equipment that was actually used on a lot of their prized recordings- lots of non-PC SS, preamp distortion, master volume amp, "digital" etc etc used and sounds just fine. A poor carpenter blames his tools.

[DavenPaget]

Agreeable . Most musicians are idiots . Big idiots .
Posers . 

[jafo]

Oh man, time for bad jokes...

How do you know the stage is level? The guitarist is drooling out of both sides of his mouth.

How do you get a guitarist to turn down the volume? Put some sheet music in front of him.

Somebody asks the bass player why he's mad at the guitarist. "He detuned one of my strings, and won't tell me which one it was!"

What do you call a guitarist without a girlfriend? Homeless.

Traditional guitarist's greeting to another: "Hi, I'm better than you."

How many guitarists does it take to change a lightbulb? Just one; they don't even have to twist the bulb, 'cause the world revolves around them.

How many guitarists does it take to change a lightbulb? Five: one to change it, and four to complain that they don't have the right gear to do it.

How many guitarists does it take to change a lightbulb? None -- keyboard players handle the technical stuff.

[jafo]

FETs are great for cleans... the exaggerated (well, relative to a tube) second-order harmonic really adds a serene majesty that works well with a lot of moods.

[DavenPaget]

FETs are great for cleans... the exaggerated (well, relative to a tube) second-order harmonic really adds a serene majesty that works well with a lot of moods.

How about this , FETs in the clean channel , MOSFETs for the overdrive channel and BJT's w/ diode clipping on a HARD-ON channel .
Anyway dares to try it? 

[zambo]

ive really been wanting to try my hand at ss amps of some sort. fets i think. Ive done a few kits that are pretty cool but am fascinated with the whole "mini tubes" fet thing..( ithink thats what I read..). So its true? the second order harmonic thing?  they must break up kinda ok right?

[petemoore]

  The Mosfet amp is a Pyramid Blue 35w + 35w, car stereo amp [no power supply].
   It is smooth and it is clean, powerful enough for my stereo needs. I copped it new for 30 too.

[jafo]

Just musing here, but IIRC a lightly overdriven BJT tends to produce a harmonic spectrum closer to that of a 12AX7... I wonder if it wouldn't be worth using a BJT preamp stage with a goosed MOSFET power stage to get a warm but basically clean overdrive. No funny biasing, no trimmers, no Fetzer design -- but no graceful overloading, either. *shrug* Maybe after the Supreux Deux I'll look into this.

[petemoore]

using a BJT preamp stage with a goosed MOSFET power stage to get a warm but basically clean overdrive
  BJT can do preamp, distorted or not, the power stage isn't very critical unless you want 'warm'...you can have clean, but if it is pushed to 'breakover' into distortion it won't be pretty, is hard on the ears and maybe the speaker.
  Tube outputs distort when pushed. Other available technology for speaker/amp includes [Mosfet, BJT, other] for clean amplification of whatever the input is...''dirty signal'' or clean signal. What goes in is basically what goes out..only marginally altered waveforms, just bigger, speakers compress and distort though.
   When a transistor with lots of current going through it [output transistor of amplifier] and it breaks into distortion for one reason or another, ''violent'' signals tend to come out...many have limiters or compressors or whatever to keep them within the linear range so no big spikes of energy that would otherwise be released as the transistor 'finds itself' again [once the Q breaks over say power supply rail, it shuts down and restarts [so to speak], this can put major stresses on the speaker, all of a sudden polarity shifts to the opposite direction the cone is moving etc. [nasty sound, not good for speaker or sound].

[jafo]

using a BJT preamp stage with a goosed MOSFET power stage to get a warm but basically clean overdrive
BJT can do preamp, distorted or not, the power stage isn't very critical unless you want 'warm'...

Yep. Very much so!

you can have clean, but if it is pushed to 'breakover' into distortion it won't be pretty, is hard on the ears and maybe the speaker.

True indeed, but gently warmed BJTs do seem to give the right ratios of harmonics without fussy biasing, and the type of distortion I'm after is a more subtle, cranked power stage kind of thing -- warmth rather than buzz -- so I don't want the BJT to distort much at all. It's a feeling rather than a sound... if anything, most people would probably call it clean. If I ever figure out how to make it happen, that is.