If one version has more power than another it can sound different simply by merit of having more headroom when levels are matched.
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Amp manfacturers that use ICEPower modules?
- Thread starter Axtman
- Start date
- Feb 12, 2006
- 60,986
- 5
- 220,768
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
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That's possible but there have been posts thru the years of users hearing distinct differences in tonal personality.
- Feb 12, 2006
- 60,986
- 5
- 220,768
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
You can easily have the same specs with multiple differences in preamp designs.
For example, the Shuttle 9.0 and 9.2 sound a little different even though the specs are the same, BUT the circuits, while similar, are not the same. I remember someone professing (without merit) that they sounded different because they used a different power module yet they used the identical power module.
Fuchs FBT-700 (and the smaller one) "Ampeg SVTish"
Fuchs FBS-700 (and smaller one) "Walter Woods"
The FBT-700 is a killer tube preamp and sounds great!
Fuchs FBS-700 (and smaller one) "Walter Woods"
The FBT-700 is a killer tube preamp and sounds great!
Question for @agedhorse; is possible to explain in layman’s terms, how, Gclass, differs from DClass?
FUCHSAUDIO
Commercial User
Our bass amps (and many other amps) are examples of how the module isn't really always the main determining factor in the sound of an amp. We make 4 models: two with tube preamps and two with solid state, but they share the 300 and 700 watt ICE modules. They sound quite different. Both versions are being praised for their great tones, but they are sonically different animals. Not good or bad, just different. We recently serviced an old Genz-Benz bass head with the same module we use. A customer test drove our amp to compare to the GB when the amp was repaired... he bought ours, and "keeps the GB in the trunk as a backup". The sound difference was staggering, and the GB had a (single) tube preamp.
We're (BLASPHEMY) now making a guitar amp with an ICE power module (300 w), and a tube preamp with a genuine tube limiter, which stops the ICE module from clipping, but rather offers a somewhat non-linear TUBE clipping, which is what guitarists want. They already see, hear and use that in many overdrive guitar amps today. Clipping an ICE module sounds quite unpleasant, can blow a speaker (don't ask how I know
), and this is a fine example of the right workaround making a darn tube-sounding guitar amp in a hybrid format. 5 lbs, 300-W (into 4 ohms), reverb, channel switching, loop, all kinds of cool stuff...
BUT:
ICE modules are GIGO= Garbage in and garbage out.
We're (BLASPHEMY) now making a guitar amp with an ICE power module (300 w), and a tube preamp with a genuine tube limiter, which stops the ICE module from clipping, but rather offers a somewhat non-linear TUBE clipping, which is what guitarists want. They already see, hear and use that in many overdrive guitar amps today. Clipping an ICE module sounds quite unpleasant, can blow a speaker (don't ask how I know
), and this is a fine example of the right workaround making a darn tube-sounding guitar amp in a hybrid format. 5 lbs, 300-W (into 4 ohms), reverb, channel switching, loop, all kinds of cool stuff...BUT:
ICE modules are GIGO= Garbage in and garbage out.
You didn't ask me, but...
Class G is a linear amplifier (like Class-AB) but allows the output stage to run at two or more power supply voltage levels. Choosing a low voltage for low signal levels improves the efficiency of the amplifier beyond the theoretical best case of 50% for Class-AB.
And if you look at it this way, Class-AB also chooses between two power supplies -- positive and negative -- or between two phases of the output transformer primary in the case of tube amps. Making the switching "transparent" to the user, so it doesn't create an audible artifact is one of the fine arts of amp design. The term for the artifact is "crossover distortion."
Class D is a "switching" amplifier, that varies the output voltage by varying the duty cycle of a high frequency signal.
So they're actually quite different from one another.
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FUCHSAUDIO
Commercial User
Sounds a lot like the old Soundcraftsman Class-H amps that had stepped supplies, if I remember corrrectely. There have been many ways to skin a cat over the years. Carver had a design that was a demand-based amp, that produced power as power was needed, although many used a coil he rufused to call a "transformer".
- Feb 12, 2006
- 60,986
- 5
- 220,768
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
Class G (and class H) are different takes on the same approach to increasing frequency. The definition of G versus H depends on the region however.
Using the US/Asian definition, class H switches the high(er) voltage rails in and out on a cycle by cycle basis using rail commutation switches.
Class G uses low and high tier linear stages, with the high tier stage remaining off until the signal exceeds the low voltage limits. The switching is integral to the discontinuous high rail linear stage.
Both approaches reduce heat generation in the output stage by reducing the voltage component in the power dissipation whenever the output voltage is below the voltage of the low rail.
Class D is entirely different in that the entire process in non-linear, based on a PWM waveform. Since in the non-linear signal the two states are either fully on or off, the dissipation is by default at the two minima of dissipation… cutoff and saturation. At cutoff there is zero current and at saturation there is zero voltage. Since Pd is based on voltage x current, both of the above conditions result in (almost) zero power dissipation. In reality there are still some small losses but they are small in well designed products.
As a person who provides sound for bar bands, I curse you for putting a 300 watt amplifier in the hands of any guitar player we work with!
(On the other hand people who sell replacement speakers will most likely praise you.)
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FUCHSAUDIO
Commercial User
Well, it comes down to soiled state watts, when compared to tube watts. I'm gigging the ODH regularly now, and "150 watts" of digital power (to my ear) sounds like about half that, when compared to a real tube amp. I gigged a 100-W ODS for years, and while this is "more watts" in terms of numbers, it's not really all that much louder (if at all).As a person who provides sound for bar bands, I curse you for putting a 300 watt amplifier in the hands of any guitar player we work with!
(On the other hand people who sell replacement speakers will most likely praise you.)
Bear in mind: This amp also has a tube limiter, so it starts to breakup a little, and holds-back before the ICE module runs out of steam, so it behaves more like a tube amp than you would expect from a hybrid. Hybrid clipping (especially with guitar) is very unpleasant. As an older player (66) and becoming more an more aware of the weight of gear, a 5-lb head and a 30-ish pound cabinet is MUCH better than my rig of ten or twenty years ago, a 100-W 112 Combo that weighed 85 lbs ! We're coming out with a new 112 guitar cabinet made of lightweight plywood, and I'm going to be playing with Neo speakers pretty soon.
Soiled state Watts... a Freudian slip, but I like it. 
In 30 years, we will be demanding amps with "vintage IcePower sound."
