Amp Emulations

[markm]

 

.....well, and a comp!!

[Simon Owen]

JFet amp emulator into a  Bobtavia (minus diodes), worth a quick experiment when I get time.

[Mark Hammer]

"Touch-sensitive"  There is another one that has multiple meanings.  For some folks, touch-sensitive means that they can still hear volume differences, depending on how hard they pick.  Touch-sensitive =  less compressed.  Sort of like the difference between a 2-diode clipper like a TS-9 and a 3-diode clipper like an SD-1.

For other folks, "touch-sensitive" means the difference in how the harmonics are introduced.  In this frame of reference, more "sensitive" means that any clipping introduced comes on gradually (as opposed to on or off) and that the character or quality of the clipping changes with picking intensity (as opposed to simply the amount).  From first hand accounts, this is the magic in things like the Ken Fischer amps - the amp only has three knobs because the remainder of the knobs are in your fingers.

[Rafa]

I think most people reffer to the second one,

For other folks, "touch-sensitive" means the difference in how the harmonics are introduced.  In this frame of reference, more "sensitive" means that any clipping introduced comes on gradually (as opposed to on or off) and that the character or quality of the clipping changes with picking intensity (as opposed to simply the amount).

Sorry to ask again:
Are ROG emulators touch sensitive according to this definition?
Maybe the previous answer was missleading as it was not clear what touch sensitive is.
Thank
Cheers
Rafa

[petemoore]

  The ice is broken
 To sound, a speaker must be used.
 How well you do here influences all sounds.
 ...building a rig.
 Choose the speaker[s/cab arrangement that fits your needs...and that tends toward the 'bang for bukk' business...you can circumvent some of that with careful shopping [having the capitol to spring on a deal that pops up etc.]...and of the thousands of choices, I tend to prefer ones that are fashioned after or are 'older celestion or jensen type'...YMMV...wholly an OT subject...
 'Many speaker choices may disallow the type of response your'e looking for'.
 Speaker connections should always be excellent.
 Then you get to the amp...another 'thousands of choices' affair/bang for bukk...many amp choices may disallow the type of response you're looking for.
 Cable>Guitar...pretty much same as above...
 At this point you can make electric guitar sound, hopefully it can sound good already.
 NOW you can try 9v circuits...whether any of them are 'tube like'...again...thousands if not millions of choices for a response to 'is it tube-like'?...most if not all of those responses having missing subcontexts...and that's the way it will be.
 It's like we're comparing a tire type, ...whether it works like a racing tire on a motorcycle or a truck...I venture to say we're all driving different type vehicles...that difference probably equates directly to the differences in our chains...Including ALL the links...speaker/amp/guitar etc.
 You tell me what 'tube like' IS and I'll take that with a grain of salt.
 

[Plectrum]

Often one of the opamp gain stages has an interesting transistor resistor section of the feedback network

I find this very interesting, I always wondered whether the clipping thresholds of diodes could be dynamically varied like this. (I know this may not be technically precise...)
I'm a freak regarding "touch-sensitive" clipping.
Do you know of any pedals that use such a network?

Grant

Theory-noob

[Ge_Whiz]

All this 'comparison' stuff is a red herring, too - when an audience hears you playing through an SS amp, with or without an, for the want of a better word, emulator, they are not mentally comparing your sound to a valve amp. They are only listening to your sound in the context of all the other sounds going on at the same time. If some musicians have trouble distinguishing 'real' from 'emulation', you can bet most audiences don't even notice. Of course, some musicians are more concerned with 'tone' than music.

[JHS]

Those FET-emulations work quite well on 32V DC and with this supply voltage the dynamic is quite good. FETs have a different reaction and generate a harsher distortion structure compared to preamps tubes.

Some older Randall preamps use a Marshall JCM 800-FET-emulation for the preamp but most of the sound on those amps is generated by the power tubes and the speakers. Randall has droppes this concept, Ampeg too and both use tube preamps on their new designs. MESA tried a FETRON on the Boggie Mk2 and dropped it after a short time and Dumble cancelled the FET-Booster on the newer amps.

Emulations powered on 9V are only OD/distortion boxes with some filtering and they are no substitutes for good tube-preamps, nothing more.

JHS

[Rafa]

Often one of the opamp gain stages has an interesting transistor resistor section of the feedback network


I find this very interesting, I always wondered whether the clipping thresholds of diodes could be dynamically varied like this. (I know this may not be technically precise...)
I'm a freak regarding "touch-sensitive" clipping.
Do you know of any pedals that use such a network?

That would be great
Cheers
Rafa

[JHS]

The MM GP3 circuit uses this trannie circuit. Both trannies are ZTX109 but in my schem one is drawn as NPN and the other as PNP. The diode generates the collector voltage for the trannie, this is is more precise than generating it it with a resistor. Never seen this in a pedal.

JHS

[Doug_H]

All this 'comparison' stuff is a red herring, too - when an audience hears you playing through an SS amp, with or without an, for the want of a better word, emulator, they are not mentally comparing your sound to a valve amp. They are only listening to your sound in the context of all the other sounds going on at the same time. If some musicians have trouble distinguishing 'real' from 'emulation', you can bet most audiences don't even notice. Of course, some musicians are more concerned with 'tone' than music.

It's not about what the audience hears, AFAIC. It's about sounding/feeling a way to inspire me when I'm playing.

[Meanderthal]

It's about sounding/feeling a way to inspire me when I'm playing.

Good point! If your tone sounds bad to you it will affect your performance, but a happy camper plays better. Which of course affects the audience perception of your performance.

[Doug_H]

I meant to add (but missed the edit window)- If all I cared about was the what the audience heard, I wouldn't lug around my amp, build stuff, and would have no use for this forum. I'd just get a POD, plug it into the p.a. and call it a day...

[tcobretti]

Doug, that is a very good point.

[Rafa]

Whats the

MM GP3

?
Cheers
Rafa

[mac]

What do you think is closer to the real thing, or will win the race, fets or computer physical models?

mac

[Mark Hammer]

Gotta qualify that.  One always has to work in real time, and is encumbered by size, cost, and physical reliability.  The other has no physical limitations, and does not always HAVE to function in real time.

[mac]

Maybe I should have asked,
How close do you think fets and computer based pedals will get to tubes? 

mac

[Mark Hammer]

DSP will win, if it hasn't already.

There are physical limitations to the properties of FETs and physical circuits.  The only limitations to DSP-based emulation is our capacity to measure and describe what is "different" about tubes and turn that into algorithms of varying complexity.  There MAY be limits to whether that can work in real time or not, but those all eventually fall in the face of newer processors anyways.

[Rafa]

I thought that digital modeling could never have that feel which real amps have.
So why GT-6 and POD are so far away of  good simulations of real amps?
Is it difficult to measure an amp ``characteristics´´.
Cheers
Rafa