Amp Emulations

[Rafa]

What does IMHO menas??
Cheers
Rafa

[R.G.]

What does IMHO menas??

In My Humble Opinion.

What I might quibble about is when the term is misapplied such that it is intended to suggest mimickry of many aspects of an amp that provide its unique character, but is actually tacked onto a solid-state facsimile of the first 3 preamp tubes.

No "might" about it. I'm quibbling. 

Here's another thing to consider:
There is a young woman standing next to me. I think she is beautiful. Do you think she is beautiful?

I think she is more beautiful than that young lady over there. Who do you think is more beautiful?

I have a group of beautiful young ladies in this room. Are they all equally beautiful?

I have here a beautiful young lady and a wax life sized model of her, made out of wax, that in every respect looks just like the young lady, but is solid wax. Is the wax model just as beautiful? Is the wax model an emulation? How accurate is the emulation?

[Ben N]

I have here a beautiful young lady and a wax life sized model of her, made out of wax, that in every respect looks just like the young lady, but is solid wax. Is the wax model just as beautiful? Is the wax model an emulation? How accurate is the emulation?

Alright, maybe just an inflatable girlfriend--but if that is all you can get...   



Ben

[R.G.]

I knew someone would pop in with that. 

OK, sure, we can do that. My opinion of inflatable girlfriends is that they are remarkably worse in every respect than the real thing. They are not a particularly good emulation in any way that I can think of. Especially if we're comparing in terms of beauty.

I'd put inflatable girlfriends at about the same place on the scale of beautiful women as I'd put playing guitar through a cheap home stereo on amp emulations. It's what you do if you're desperate and will put up with something that is an "emulation" primarily in your own mind.

Frankly, I was thinking more of the differences in "beauty" between real, live women and a poor similacrum; and to prove the point that we might all perceive beauty as being somewhat different.

[Rafa]

Im thinking about building my first tube amp or preamp, I saw the first fenders look easy I would like a tweed deluxe but it has 5 tubes so I thoghut about the small champ which has 3 tubes, is the sound similar between this two amps, can I build it with bright input instead of the common??
Whats the difference between 12ax7 and 7025? whcih one sounds best?
Can I use a SS rectifier to avoid using a third tube, will the sound change much?
Thanksss
Rafa

[Gus]

The problem with this stuff is the wrong end of the amp is being modeled what ever you want to call it.  companies put tubes in the pre because it is cheaper is my guess: however with bass a nice tube pre with a high power solid state amp can sound very good.

Look at the Music man amps and some others all solid state till the output tubes and transformer.  Have you heard a music man amp? the opamp type does seem to make a difference lf353s, 4558s or even TL072s I have been told..

Pentodes and beam tubes interacting with the transfomer speaker load mess being driven hard is what most of the sound is from IMO. You got screen grid current sometimes and how the heck do you model that mess of overdriven pentode beam to a M what ever alloy stack of iron and copper that might be wound different ways?

Don't believe me do a test take a solid state pre into the effect loop for solid state pre to tube power amp..

I have a PRS head ICs and solid state outputs interesting amp.  I think only 190 made.  I bought mine at a guitar show it is in not so good shape but it does sound good. 

[Gus]

edit

[lovric]

R.G.'s comparison genuinely provoked me and reminded me of the question of, let me say, the inner beauty. you call it what you like since this got metaphysical already.

i give you an anecdote, sincerely not intending to hurt anyones feelings, it was my wrong in the least. here it is: one time, at the sauna me and some of my male friends offered our female colleague to join us.    promptly, one of my friends who did not join us in that proposition told her: 'don't be bothered. i'm the only one married, you have to understand them, they haven't seen how it looks like yet.'

now, back to the sound(ness). i got first non MV Marshall when i was 16. i strongly thought that everything that preceeded it was an exagerration. i thought of it not only as a burden in sheer weight but also as of a huge disappointment. then one day i happen to come to a proper rehearsal room. the drummer was so loud or so i thought and it never occured to me that he should be after all the gigs i have had seen up to that moment. so, i turned my volume to 6. ok, maybe 7.

...

nowdays, sort of retired, with most of my buddies not anymore interested in playing, and myself being in financial narrows, im confined to my room. neighbours and the rest of the 'real life' surroundings. i just accept the 'jfet emulation' as a white lie and it warms my heart.

[mac]

I have here a beautiful young lady and a wax life sized model of her, made out of wax, that in every respect looks just like the young lady, but is solid wax. Is the wax model just as beautiful? Is the wax model an emulation? How accurate is the emulation?

Good & funny example RG!

Both J900 and AVT2000 look very cool externally, but my ... emmhh... "distorted" mind like to "gig" with the real thing... no wax, inflatable or silicon surgery emulation... but I admit I like to experiment sometimes...

But there are so many people under the sun, and some of them do really like inflatable girls, some do need a silent Playboy mag, some simply can not afford a beautiful girl, some like both worlds! 

---

I remember one day in Buenos Aires six month ago. I was in a crowdy music store looking for a 15 to 40 Watt tube amp. The salesman told me to try a chinese AC30 2x12 @ U$S1.350 which is out of the budget for many people here. There were a couple of kids near me testing Digitech GNX,  Boss GT and Marshall AVT. They looked very pleased with that toys, but when I crancked the Vox and played a few chords, most kids were surprised by the real thing. They all came closer to listen and ask. Finally the Vox seemed too overpricey for me and went for a Laney VC30. The salesmen not only failed to sell me the Vox but the digital processors and AVTs to those kids, who are probably saving peso over peso to buy their first tube amp.


mac

[petemoore]

  Like Jfets' do...
  Sound alot like a tube amp, @ low volume, More like a cranked tube amp than a big tube amp turned way down.
  What do tubes and Jfets have in common?
  They can boost
  They can distort
  They can be compressed
  They can be voiced and can drive tone controls etc.
  They can both provide a wide variety of sounds.
  They both do stuff the other doesn't
  Where do they differ?...
  Gus mentioned a good one...Jfet Emu's stay near the front of the chain.
  Tubes Drive speakers
  Speakers load tube outputs
  Small Signal Jfets Don't drive speakers
  There is Alot that can get to going on when a tube amp is 'leaned on' that doesn't happen in a 9v [low voltage] Jfet circuit which follows a cropped tube amp schematic.
  Power supply Sag.
  Output section and speaker doing their dance...
  Even with a stiff supply and no speaker...Jfets'll sound differnt than tubes...better and worse...depending on...all the schtuff it depends on...

[Rafa]

Peter:
So if we take for example the professor tweed and we modify it to make an amp it involves we change the fet that should be in the power amp for another and we supply it with higher voltage (and the speaker of course), should it be closer to the real amp?

Who stated Fets are like tubes??
Fairchild, scientifics, some anonymous guy??
Which is the susbtitute for the 12ax7? the mpf 102, if so why j201 sounds better

This f4t thing is not really clear for me,
This might be a question for ROG guys why do you use mostly always the j201 to substitute 12zx7.ecc83,6l6,6v6,el34

Cheers
Rafa

[mac]

I do not know if there is a fet that can work at 100-200V and deliver 5-15 watt in single-ended class A. I think of a 2 or 3 fets at 100-200V in the preamp and a single-ended output fet + output transformer driving a speaker. Or mosfet, assuming they sound the same.
But I guess that someone has already built it if it is possible.
How will it sound? No idea.

mac

[puretube]

yes, there are such devices...

[Rafa]

Are they good?

[Dragonfly]

I've stayed out of this thread till now, but I figure I should get my $.02 in !

Really, what the hell does it matter ? To quote R.G. "beauty is in the eye of the beholder"....well, some may love the sound of a jfet amp emu, some may not. I know people who LOVE Fuzz Faces, and people that think theyre the plague of the Earth. Are either of them right? Are either of them wrong ?

People build kit cars of Lamborghini's because they can't afford a real one. All the people who own "real" Lamborghini's turn their noses up at them. But the people who own and drive the "kit versions" are plenty happy driving around in their cars. Are the kit car and the real Lambo the same ? Of course not. But I would venture a guess that many of the kit car owners get as much, and sometimes more, enjoyment from their vehicles than the Lambo owners. Less maintenance, less hassle, less worry, similar styling.

So, to sum it up....if YOU like it, then who the hell cares ? To quote Joe Meek "If it sounds good, then it is good".  And to paraphrase R.G, "Beauty is in the ear of the beholder".

AC

And BTW...IMO, they should be called "emulations". Just because you "emulate" your older brother, does it mean you're "the same"?  Of course not.

[Rafa]

people that think theyre the plague of the Earth

Im one of that guys, I havent played god fuzzes but I didnt liked the ones which Ive played,
Cheers
Rafa
As I see (as dragonfly said), if its sounds good its a good stompbox, but the problem I think is which sounds best are tube amps, so people does not feel happy with the emulators available, they want to get as close as possible and f4t is not an accurate method maybe.
IMHO<---(Now that I know what it means  )
Cheers
Rafa

[tcobretti]

people that think theyre the plague of the Earth

Im one of that guys, I havent played god fuzzes but I didnt liked the ones which Ive played,
Cheers
Rafa
As I see (as dragonfly said), if its sounds good its a good stompbox, but the problem I think is which sounds best are tube amps, so people does not feel happy with the emulators available, they want to get as close as possible and f4t is not an accurate method maybe.
IMHO<---(Now that I know what it means  )
Cheers
Rafa

If you haven't, you need to build some of these ROG simulators.  They sound more tube-like than almost any solid state circuit I've heard, certainly more tube-like than any solid state amp I've ever heard.

[d95err]

Im thinking about building my first tube amp or preamp, I saw the first fenders look easy I would like a tweed deluxe but it has 5 tubes so I thoghut about the small champ which has 3 tubes, is the sound similar between this two amps, can I build it with bright input instead of the common??
Whats the difference between 12ax7 and 7025? whcih one sounds best?
Can I use a SS rectifier to avoid using a third tube, will the sound change much?

Go for a full amp, not just a pre. The poweramp is where the biggest difference in sound between tube and solid state is.

Take a look at www.ax84.com. That's like a "DIYstompboxes" for tube amps. The AX84 P1 amp could be a perfect project for you. It is a simple single-ended amp, like a Champ but with a full tonestack. This leaves lots of room for tweaking and modding. You can expect lots of support from the AX84 community, as well as thousands of ideas and tips for mods and tweaks.

In a single-ended amp, the choice of rectifier type does not matter for the sound. This is because the amp will be Class A and therefore have no powersupply sag. The only difference will be the voltage (tube rectifiers drop 30V or so compared to solid state rectifiers).

I think the 7025 is a "military" grade version of a 12AX7. From what I understand it's a bit more "hifi" sounding, so I guess it works well for clean preamps. They are very similar, so you can just swap them to see which one you like best.

[puretube]

so it looks like what is searched for is:

Triode-clipping, and Pentode-saturation ( "TCPS" )

without power-supply sag ( "PSS" ),

plus output-transformer hysteresis ( "OTH" ),

no negative feedback ( "NNF" )

out-of-their linear range speakers ( "ORS" ),

and cabinet resonances ( "CR" ).

All of that miked well ( "MW" ).



BTW: I do wonder, whether all that distortion coming from
the phase-inverter working in its non-linear region is in fact
the audible distortion that is mainly the cause of some amplifiers`
sound,
(like it has been mentioned at various places on the web),
or if the non-linear behaviour of that tube is of the kind
that is being outbalanced
in the output-transformer`s two "antiparallel" windings...

[Rafa]

Thankss a lot guys
Its true the only fet stompbox Ive built is the Blue Magic, So Ill have to try a ROG one
Which one is the most touch sensitive for you guys?
For the tube amp Im saving some money becuase right now Im bankrupt
Cheers
Rafa