Pro Amps I.e. Crown, Qsc

[E-Stat]

Now, the real question: how does the consumer market get away with charging at least twice as much for all their amps?

I owned a Crown amp long ago. Reliable and powerful, but not in the same league sonically as the Threshold that followed it. The power supplies are typically much smaller on pro amps. My CDP weighs more than the QSC amp.

rw

[pelly3s]

most modern pro amps use a switching power supply thats why they are getting so light and seem to have a small power supply. I am yet to see too many home amps that have a supply as big as a Macro Tech 10000 (any amp with two power cords is cool), or even that a 5000 oh and lets not forget about the huge supply in the QSC RMX 5050. I do miss the days of my Macro Techs but I managed to get more power and lost about 300 pounds off my racks by going with Itech's.

those QSC studio reference amps are great. Its a close call between those and the crown reference series on which one i like more. the QSC does look a lot cooler

[mixadude]

These and other reasons are why I haven't been too gung ho on hifi gear of late (the last 30 years). I use the big big stuff for real audio. Don't care much about an iota here and there, a huge flagship AVR pretty much foots the bill for my home system. When I do real audio, I use truck fulls of heavyweight stuff.

All that being said, I do appreciate the schooling I'm getting here in this arena... thanks one and all

[E-Stat]

I am yet to see too many home amps that have a supply as big as a Macro Tech 10000 (any amp with two power cords is cool), or even that a 5000 oh and lets not forget about the huge supply in the QSC RMX 5050. I do miss the days of my Macro Techs but I managed to get more power and lost about 300 pounds off my racks by going with Itech's

What is the capacity of either amp in joules?

rw

[kexodusc]

What is the capacity of either amp in joules?

rw

Curious, I can't figure out where you're going with this question...but I'd love to know.

[pelly3s]

im in the same boat.

i would love to see any hifi amp come close to the power and current of the MA-10000. The thing was used to power MRI machines. Its completely stable all day long at .5 ohms

[E-Stat]

Curious, I can't figure out where you're going with this question...but I'd love to know.

That would be quantifying the notion of "huge supply". As a point of reference, my mono amps store 250 joules each.

rw

[kexodusc]

That would be quantifying the notion of "huge supply". As a point of reference, my mono amps store 250 joules each.

rw

I'm missing something here, been a few years since my last physics class. But the relevant unit of application (power) is still watts, no? Regardless of joules.
With a unit of time introduced, wouldn't the number of joules and watts be the same anyway? Ie: 1 joule = 1 watt-sec?

(as I said, I'm very curious were you're going with this)

[E-Stat]

I'm missing something here, been a few years since my last physics class. But the relevant unit of application (power) is still watts, no? Regardless of joules.
With a unit of time introduced, wouldn't the number of joules and watts be the same anyway? Ie: 1 joule = 1 watt-sec?

There is no direct relationship with the quantity of watts from an audio amplifier and the stiffness of its power supply. They vary widely indeed. The formula for stored energy is J=CV2 /2 where Joules = Capacitance X Voltage (rail) squared divided by 2. (Sorry I can't get the HTML superscript tag to work). Do the math on some amps you know. Rated wattage is irrelevant. I know of some 100 watt amplfiers with stiffer power supplies than most 500 watt amps.

I liken power supply stiffness to torque. How quickly can you deliver those watts? For most sound reinforcement applications, the question is moot. There is no dynamic range to speak of. While the amps may be cranking out kilowatts, they lack the ability to dynamically jump like the best amplifiers are capable of. It took me years to fully understand what reviewers meant by an amplifier having "authority". It is that utter sense of control and ease at any power level with the ability to literally startle you on wide dynamic range material. As in truly live, unamplified music.

Quality and quantity are not the same.

rw

[jneutron]

An interesting thread..what is a joule???

E-stat...everybody knows power cords don't make a difference..why do you continue to say this..just buy some (more) vanilla cords...


I would be concerned with several things with respect to the total energy storage of the supply bank..

1. How much droop occurs during heavy loads, and how this droop level makes it's way back into the electronics..output stage gain modulating (hfe vs Vce down neat Vce(sat), modulation of the damping factor in all four output quadrants.

2. How the input circuit re-charges this drain, both haversinewise and conductivity coupled cap draw back through the bridges.

3. For smps setups, are they two stage with PFC, or single stage..at least the PFC has spare energy to feed in during line zero crossings. (single phase systems).

4. The hf capacitance characteristics of the supply caps and loop coupling from the output draw back to the xfmr and out the line cord..geometry based, of course..a larger bank of capacitors makes the loop coupling less as a result of spreading the full current out among more spacial volume, thereby reducing the loop coupling to nearby circuits.

5. How inadequate the star grounding scheme is for large, hf current draws into low impedance loads.


Me, I just play with my rmx 1450..so far, it has served me well..but my applications have the amp over 35 feet from the front row of audience..about 100 feet from me (when I am hovering over the summer hired school kid who runs the sound and lights.) So I am unconcerned with fan noise.

Cheers, John

[kexodusc]

I owned a Crown amp long ago. Reliable and powerful, but not in the same league sonically as the Threshold that followed it. The power supplies are typically much smaller on pro amps. My CDP weighs more than the QSC amp.

rw

Different ball game quite often though...power supply size by itself is no longer a good measure of an amplifier's ability. Even for home audio amplifiers. Unless they are the exact same topology. Even then, there's differences in PSU's too. Chasis, fins, the use of fans, etc. all contribute to weight as well. A/V receivers still go cheap quite often, but even $300 receivers have seen credible, real power increases in recent years, ability handle lower impedances a bit better, while significantly reducing size and weight of PSU's.

There's little doubt in my mind that many of the established amplifier manufacturers keep using old school, heavy, less efficient designs simply because a great portion of the target market uses weight as a quick evaluation measure. They can be cheaper to produce too.