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The ADA Ampulator may use a 12ax7 as its power tube, and load it with something other than an output transformer.

Tubes used for low-watt power amp section:
Hughes and Hettner Crunch Master -- EL84
Hughes and Hettner Cream Machine -- ECC82
Hughes and Hettner Metal Master -- ECC83


If the Ampulator uses a 12AX7, then I trust the Crunch Master the most of all these. I lean toward squashy rather than hard power tube distortion, because I can get plenty of metal hardness from distortion. I like to exagerrate the power tube distortion enough to say "this is *real* tone -- you can't do this by cutting corners". To me, power tube distortion is what defines spine-tingling pro sound -- it's the very rarity of it that helps make it heart-stoppingly precious and impressive.

But I would like every bedroom guitarist, experimental guitarist, parlor guitarist, cafe guitarist, and studio gear head to be able to flip a switch and have totally authentic power tube saturation tone effortlessly, conveniently, at any volume. That's why the Holy Grail for power tube packaging is the footpedal. If you can take power tubes down off their pedestal and just make them another cheap, dinky little foot pedal, *then* I would say that we have conquered and harnessed tube tone, because then, people would instantly be able to swap the order of effects and experiment, with power tube "saturation pedals" being just one more simple module. At low levels, you can really *experiment* with tone for long hours, with no worry about the room noise level.

You can work out on the Crunch Master abdominal exercise machine while listening to the playback of your Crunch Master guitar processor recordings.

It's difficult to simulate room diffusion and multiple speakers, which are a large part of professionally recorded tone. Power tube saturation is not enough to simulate a traditional cranked amp recorded professionally. A single speaker with no room reverberation sounds 1-dimensional compared to multiple speakers in a room.

I have other great doubts for speakerless power-tube based amp simulators:

o I doubt that an inductive load feeds back to the power tubes dynamically like a speaker does.
o I doubt that a low-pass filter sounds like a guitar speaker.
o I doubt that a linear filter sounds as good as a stressed speaker pushing air, which might add special distortion, compression, responsiveness, and smoothness.

A properly designed load and low-pass filter, with proper reverb settings, might be able to perfectly emulate a professional amp tone. The amp emulators I've worked with so far sounded terrible. My tube amp, speaker isolation cab, and microphone in the effects loop of the 2101 processor *certainly* sounded authentic, even though the speaker isolation cabinet has no diffusion. I wanted badly to put both a dynamic mic and condenser mic inside the cabinet, because a Greenback speaker and SM57 mic sound extremely British -- brown, closed, and warm, not open and bright like Fender amps with 10" speakers. The 15 watt tube amp was probably too powerful for a condenser mic inside the isolation cabinet. But with only 5 watts, produced by your friends' amps, I could then put

Based on my early experimentation, I don't trust speakerless amp emulators. I definitely trust speaker isolation cabinets, tonally. But I would like to try out all the emuluators I mentioned -- Power Brake, HotPlate, Ampulator, Crunch Master, and Metal Master, as well as the Demeter isolation cab and the MicroRoom.

I am against the term "guitar amp". It's got too many assumptions that need to be overthrown. It implies a 50 watt power amp driving a very loud guitar speaker, often with echo effects and reverb units placed poorly, before the power tubes. We need to break apart "the amp" into subsystems and recombine the subsystems:

What is a "guitar amp" in terms of subsystems?

input eq
preamp distortion
post-distortion eq
post-distortion effects loop
power supply
power tubes
output transformer
speaker cabinet

(And then there are room reverberation, microphone, and post-amp processing at the mixing board, which could include anything in a guitar multieffects processor).

Since room reverberation is such an important part of speaker tone, designers of systems using a speaker isolation cabinet or inductive load could offer some models that include tastefully chosen reverb -- *after* the saturated power tubes, where God meant reverb to go.

Notice the mention of reverb below:

"The metal master has no output valve, but it uses two ECC83s (one for
tone I think) to get a great rock sound that beats most semi-pro combos
(speaker simulation built-in). Used with delay and reverb, most rock
sounds can be achieved."

Hendrix didn't use much reverb.

I could probably give some innovative input on product design for amps -- not the circuitry, but rather, the design goals for packaging and controls. I have a good sense of what features, inputs, outputs, and controls are most valuable for the average would-be guitarist. For example, the two-knob Fender Pro Jr. amp is underkill and the Digitech 2101 is overkill for the majority of guitarists. If they are going for minimalist, I don't know why the Pro Jr. bothers with a tone knob. My antique amps don't have such superfluous frills. But when amps are this minimal, then I start thinking of them as mere power amp *modules* that would fit well as part of a modular system... but by that time, I'm no longer thinking of the amp as a traditional "guitar amp", but rather, as a tube power amp module that happens to be dragging a preamp section and speaker cabinet along behind it. The Pro Jr. is not very usable -- it should have a few more features, or a few less. It would be more popular and generally useful either as a pure rack-mount power amp or as a more self-contained amp with a few tone and distortion controls.

I also question the usefulness of the 15 watt range. It's too quiet to compete with drums, and too loud to play at home. If you want a practice amp, let's talk *1*, *3*, 5, or *maybe* 7 watts! 15 is too much, yet not enough. I no longer am enthusiastic about 15 watt amps. My heart is set on 1-to-5 watt amps, both for my own needs and the needs of millions of guitarist/consumers out there.

I have ideas for basic tube "amp" products, and advanced "amp" products. The original Groove Tubes unit was poorly designed -- it lacked internal modularity; it lacked input/output jacks between the preamp and amp, and between the inductive load and the simulator. They used too powerful of tubes for my needs (2 6v6) and the unit was very cumbersome.

Power tube saturation products should be an exploding market for both bedroom and stage guitarists. This category of products will be the music technology innovation of the 90s.

-- Michael

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