TS > TS > LS> of 2925 watts plugged into a worst case wall
TS > TS > LS> plug.  Both amps are
TS > TS > I would estimate that your 2400 W amp can only sustain 1500 TS > W
TS > in a worst case wall plug.  If you can prove otherwise,
TS > LS> That's what the FTC claims in these specs.  But that differed when i
TS > You've since said that this amp is wired to take two 20 A
TS > 120 circuits via dedicated twistlocks.  That's hardly an
TS > "ordinary wall plug" worst case, sometimes a flaky 15 A
TS > circuit.  Transient peak ability doesn't make an amp
TS > capable of greater than 100% I/O efficiency.
Well, this amp when it had 1 measly toroid, it was sustaining the wattage at 
2400 watts RMS (1200 per channel at 4 ohms), but it was dimming the lights 
FROM the fusebox i had it directly connected to.  It was affecting all the 
lights in the place, but it was sustaining 1200 watts per channel drawing no 
more than 15 amperes total.  I was not measuring peak either, i used an 8 ohm 
Guass brand woofer to test the amplifier out both channels driven, and one 
channel driven.  When i measured one channel at a time, it held 1500 watts 
into that channel at 4 ohms.  When i measured both channels driven at once, 
it was 1200 sustained watts per channel using a 100 hz tone for 5 seconds.  
This was all from an ordinary wall plug.  With this amp the way it came 
before i made the slight modification it was doing fine except alot of people 
insulted the amplifier for 14 hours because it was running 14 hours in 
clipping.  Then i figured out that obviously i would blame the other 
amplifiers for my larger amp clipping because the people at the club plugged 
4 amplifiers into the same power bar.  Breakers did not pop on anything, but 
all the amps were blinking green and red for activity and clip all night.  At 
3 am, we had a carver amplifier catch on fire after the fan melted.
TS > LS> upgraded the toroid and the capacitors FROM it's
TS > LS> 6800mfd.  PLus i had to up the bridge rectifiers from
TS > LS> 30 amperes to 60 amperes because the thermocouple kept
TS > LS> killing the power because the rectifiers were the
TS > The usual rule of thumb for caps is 1,000 uF per amp of
TS > intended PS capacity.
TS >  Power supply parts are expensive and take space, and so
TS > some designers cut corners.
Yes, as with my amplifier, and many other related 2 rack space amplifiers.
TS > TS > LS> watt amplifier like the one above, but i modified the TS > LS>
TS > power supply, and i measured it can hold 4,000 watts TS >
TS > LS> total power, RMS, but i needed a 35 ampere breaker
TS > TS > 4,000 Watts is a rate of energy transfer, not an amount of TS >
TS > energy.
TS > LS> Well everytime i tried to make this amp huskier on
TS > LS> it's wattage, what you said above is pure BS.
TS > Wrong.  Might I suggest you study basic physics, and
TS > international standard units?  "Watts" are not a quantity
TS > that can be "held".  Care to try for watt-seconds,
TS > Coulombs, or some suitable unit?
TS > LS> is pure lethal because it supplies 100 amperes with a
TS > LS> 50 percent reduction in damping factor at 167 volts.
TS > I presume you're talking about some undefined momentary
TS > peak measurement here, and a coupling resistance or diode
TS > drop between upper and lower supply rails as to the nominal
TS > damping factor?
No diode drop, when the amplifier runs bridged, it reacts like every 
amplifier out there, 50 percent reduction in damping factor.  Damping goes 
from 700 to 350 in bridged mode.
TS > LS> I can ARC weld with this amp in bridged mode without
TS > LS> clipping and a bit of heat off the heatsinks in the
TS > LS> amp.
TS > I can't see that sustaining arc welding, as the current
TS > ability would be too low for anything but momentary surges.
TS > Real welding uses lower voltages that sustain what you're
TS > tlaking about as peak currents only.
well the arc welding was done using a 500 hz tone continuous into the 
amplifier, we had to wear ear protection because the 10 guage plate we were 
welding (rod) was amplifying the noise.
TS > TS > Do you know what the ESR of the filter capacitors in that TS > amp
TS > is, and what their capacity and no/full load rail
TS > TS > voltages are?
TS > LS> Yes, explained below.  This amp uses dual
TS > LS> complementary rails instead of trying to compare it
TS > LS> to some cheapo single complementary rail amplifier
TS > LS> like you are trying to do.
TS > Ever see the Stewart amp design?  By comparison, you could
TS > argue that dual rail voltages are a kludge.  Dual rails
TS > have been used as the basis of 1 kW AM broadcast
TS > transmitter designs popular from 1976 to 1985.  Amp
TS > designers may have borrowed the idea there, while such TX's
TS > have moved on to quadrature and digital waveform synthesis
TS > designs using MOSFETs.  Every design is some kind of
TS > compromise, as there are different distortion modes and
TS > design complexities to most fancier circuits.
Very low distortion in my amplifier, 0.0018 percent near clipping.  And it 
does not use class D switching like you described above with am broadcast.  
AM broadcast is totally different, that is a class C subject.  My amplifiers 
are class A/B.  It sustains class A up to 10 watts, then switches to class 
AB. Class B has no inherent noise anymore since it has been changed over the 
years for more efficient and clean output.  Class D is 90 percent efficient 
because it is high speed switching.  This class D switching is not suitable 
for mid and high frequencies, class D is used in subwoofers these days for no 
heat when driving loads down to 1/4 ohm, that's right, 0.25 ohms, sustained, 
not limited run time basis.
TS > LS> The ESR of the caps is 6800mfd per rail.  It uses a +145v, +78v, 0v
TS > -
TS > ESR is equivalent series resistance, the internal impedance
TS > of a cap which causes heating and limits current delivery
TS > ability.  It usually decreases with larger capacity, but is
TS > also affected by other design actors.  Low ESR, of a few
TS > hundredths of an ohm or less, is typical of better quality
TS > caps used for amp filters, strobe or snubber circuits, etc.
Well all i know is these caps are blueish green, 4 for each channel on each 
rail.  6800 mfd between the +145v and +78v rails, another 6800 mfd between 
the +78v and 0v rails, another between the 0v and -78v rails, and the last 
one between the -78v and -145v rails.  I dunno what quality of caps are used 
in these amps, but they are way under rated for the temperatures of this amp 
at extreme power levels.  The amp shuts down at 125 degrees, the caps are 
bolted right next to the mosfet rail it drives and the caps are rated for 80 
degrees. Those caps are still in there, but each channel has been upped to 
1/4 farad (250,000 mfd) now total.  The forward bias current drops on this 
amplifier after 20 seconds then the amplifiers transformers and diodes get 
warmer to try to sustain the amplifier AND charge the caps at the same time.
TS > LS> 78v, and -145v rails out of the power supply to the
TS > LS> rails.  6800mfd per rail is the capacitance in the
TS > LS> amplifier, which is not much.  The rails were built
TS > 30,000 uF or more would seem desirable for such an amp
TS > IMHO, unless it was of a supersonic DC-DC converter design.
TS > With the dual rail bridgable mono design it appears you're
TS > describing, 4 such caps would be required, not exactly a
TS > small chassis real estate allocation.  Using separate
TS > supplies per channel, you'd be looking at 8 caps, though
TS > dividing the current handling.
No HF switching here, all off of a traditional 60hz power supply, this 
prevents tweeters from frizzling.  Peavey amplifiers use switching, and you 
could smell the speakers frying.
TS > LS> this way in the amplifier to prevent harsh clipping
TS > LS> on the output rails and causing the back EMF from the
TS > LS> speaker from interefereing with the damping at high
TS > LS> levels of power.  A wall plug supplies 1875 watts at
TS > That sounds irrelevant.  It has to do with thermal
TS > efficiency and idling power considerations.  You hit
TS > headroom limits at the same point as if the amp had single
TS > rails only of identical upper volatge and current
TS > capability.
Thermal efficiency is unusual in this amp, it runs hotter the more it idles.
TS > LS> breaker panel, it can sustain exactly what the
TS > LS> manufacturer said it would - 3,400 watts.  And yes the
TS > LS> amp now NEEDS a 35 ampere breaker from the main
TS > That's pushing it, as while 4200 watts in is credible for a
TS > high efficiency amp, and likely wouldn't trip a breaker of
TS > that rating for a few hours, it's exceeding normal
TS > sustained loading codes.
Well i did say my amp tries to sustain class A (class A is 25 percent 
efficient) and then switches to class AB (75 percent efficient) at higher 
levels.  Slew rate is only defined by the op-amps.  I ripped out the 74x's, 
and replaced em with 5388 op-amps, the slew rate went from 60v/ęs to over 
250v/ęs.  Changed the harsh sound of this amp to sound WARMER than a tube 
.
TS > LS> sustained 80 percent duty peaks.  Energy transfer is
TS > LS> 75 percent efficient in the most worst case (plugged
TS > LS> into a 18 or 16 guage line cord).  This is what i
TS > That's not a measure of the amp, but is a safety hazard.
Well the amp did warm up a few cords, but none of them melted, even if i 
limited the current by using 16 guage instead of 12 guage like i was supposed 
to.  This was using rock music, which does not require as much current as 
what these clubs push into the systems.
TS > LS> measured out of the amplifier, total, each channel
TS > LS> sustained at 2.67 ohm loads (3 8 ohm speakers in
TS > LS> parallel) with a bit of reactivity and back EMF from the speakers.
TS > Actual speaker Z isn't the same as nominal at most
TS > frequencies.  Any power claims you make based on voltage
TS > measurements into speakers are suspect.
I measured 167 volts out of this amplifier sustained bridged.
TS > One reason amps need more current capacity than a nominal
TS > power output should demand, and benefit from low damping
TS > factor, is that speakers do have reactive quirks plus
TS > resistances and impedances below nominal at some
TS > frequencies.
Well my amplifiers do not let go of back emf like lowly damped amplifiers do, 
there is no sense with some of the complicated bass program i push into the 
amplifier.  The damping factors in these amplifiers are a MUST in order for 
the cone to be stopped BY the amplifier itself and not to let the cone return 
to it's position during complicated music material because it would sound 
like shit.  I have heard what a 100 watt amplifier with a damping of only 50 
sounds like at high volumes, and a 100 watt amplifier that i drive (carver 
clones) with damping in excess of 500.  There is a MAJOR difference in sound 
and response.
Laszlo Sokolai
Team ANTI-Windows95/PRO-OS2/PRO-Unix
lsokolai@bbs42.com
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