I don't normally frequent the SS pages however curiosty for bass driving amplifiers had tempted me. Here we question anyione contemplating 100 watts. What do i see there 500w, 900 watt 20 Kw Watts all this about!!!
Not for easy listening at home! 😀
One or two KW is good for pro sound systems.
(and knuckle-draggers who think it's a good idea to bend car body panels with their subwoofers)
The 20KW one is either a joke or a really bad design. Either way it won't work. If somebody could translate that into Turkish and Arabic, we might put an end to all the "i no english where i can get PCB???" posts in those threads.
One or two KW is good for pro sound systems.
(and knuckle-draggers who think it's a good idea to bend car body panels with their subwoofers)
The 20KW one is either a joke or a really bad design. Either way it won't work. If somebody could translate that into Turkish and Arabic, we might put an end to all the "i no english where i can get PCB???" posts in those threads.
If you want air to move at really low frequencies, solid state, good damping factor and low distortion, you end up with a SS amp of around 400-800 Watts.
Rockford Fosgate® - T15kW
Not quite 20K, but it exists, and works 🙂
Not exactly sure what this has to do with tubes, though...
How about a 25,000-watt tube audio amplifier? There are some still in use, though usually as backups anymore. Their purpose? Modulators for 50,000-watt AM tube transmitters, usually using the same type of tubes as the transmitter finals. Yes, the modulation transformers are *huge*, almost the size of a small substation transformer. 🙂
Todd in Cheesecurdistan
Todd in Cheesecurdistan
There are a couple of 891-R tubes up on Ebay now. 4.5 KW plate dissapation Mu of 8 for the ultimate single ended amp!
Two (2) Westinghouse 891R 891-R Low Mu Triode Tubes - eBay (item 110524731708 end time May-02-10 18:43:20 PDT)
Looks like 2 modulator tubes...
Two (2) Westinghouse 891R 891-R Low Mu Triode Tubes - eBay (item 110524731708 end time May-02-10 18:43:20 PDT)
Looks like 2 modulator tubes...
Water cooling is the way to go at thet power level unless you want to put the amp in a separate building. In the old days some of the big stations had a pond with a water fountain in fromt of the building. Looked nice but it was actually the heat exchanger for the cooling water.
Google wlw 500 kw if your into that stuff.
Jim
look at the specs of that fosgate amp. its 500w pch at 4 ohms. its a 2000watt amp and in car stereo that's not that big of a deal these days with switching amps. they are saying its 15kw as the sum of all channels into .5 ohm load which is really a bogus spec.
You want at least 6dB headroom, so with a 400 Watt SS amp, you end up with a realistic usable 100 Watt... Not that much in the 20-100Hz band, fed into a low efficiëncy, low distortion driver...
Not really when you consider its intended use. This is a competition amp, it is not intended for listening. If you have never heard of (or even witnessed) an autosound competition Google "db drag racing". The goal is to score the highest SPL on a meter placed in the car. The current "best in class" cars are in the 160+ db SPL range. Of course there are no humans in the car, and in many cases the car may not even be capable of moving under its own power.
I saw a "sound off" competition at least 15 years ago where many of the local "boom boom" cars were tested against each other (often with occupants) and some scored in the 120+ db range. Then one of the auto sound companies (might have even been RF) rolled out "the truck". It was a small pickup truck. The entire bed was filled with amps and batteries. There was this large fiberglass horn filled with woofers that emptied into the cab where the back window should have been. All of the windows had been replaced with thick Lexan. It was operated by remote control from about 50 feet away and sent the db meter into the 150 region. I was about 100 feet from the truck and it was loud.
The amp is specced to deliver 7500 watts X2 into a 1 ohm load. 7500 watts will set many monster speakers on fire. Mere mortal speakers will never make a sound, the voice coil will just open. Don't ask why, but I plugged a lot of raw speakers into the wall outlet in my younger days. Only the big woofers last for more than a few mS at 1800 watts (wall outlet into 8 ohms). An amp like this will need several BIG woofers in parallel. A 1 or 1/2 ohm load is not out of line for something like this.
Now there is a company claiming 180 db from a single woofer. That sounds a bit hard to believe. I am not sure that you could get 180 db with dynamite!
From the Rockford Fosgate web site:
• WARNING! This amplifier is specialized for competition use and is capable of extremely high power output for powering large arrays of woofers in a single system.
• The below diagrams are simplified examples of running the amp in 4-ch. STEREO mode.
• Experienced installers can calculate more complex wiring methods for large woofer arrays.
Back to the topic. I have recently listened to a breadboarded 200 WPC tube amp through my little Yamaha NS10 speakers. Yes it was loud. No I didn't play it at full tilt for more than a few seconds for fear of frying my speakers. How would I describe it at reasonable levels? In one word effortless. The amp will never clip in normal use, and for that reason I intend to build a more permanent version.
Last edited:
Watt that's all about is solid state devices and their absolutely horrid clip behavior which becomes even worse under the high levels of gNFB that these require to linear them up.
You absolutely do not want a solid state amp to clip since this will result in significant sonic deterioration. VTs have a much gentler roll off as they approach either cutoff or saturation. Even with gNFB, the clip behavior is such that an occasional excursion into clipping just isn't heard. A VT amp will play louder than an equivalent SS amp before the sonic degradation becomes noticeable.
Unless you need to fill an arena with sound, you just don't require much more than about 30W from a VT amp for most normal home listening requirements.
I did a SS design that's a 3.0W amp, yet it uses a power supply that could put out 12W if you sent the finals all the way to the rails. I could market it as a "12W amp", however, you wouldn't want to listen to it at that level. Limited to 3.0W, it sounds better than a whole bunch of commercial SS amps.
A hard clip on many solid state amps produces so much high frequency energy that it is possible to blow your tweeters with only bass music. I have seen tweeters blown by turning up the bass control in the dance studio where my daughter used to take lessons.
100WPC solid state, Big Box amp took out the tweeters of the Technics speeks these relatives had, and that was desite a special tweeter protection circuit. No idea how long that situation had lasted before they asked why their stereo sounded so lousy and had me check it out: blown tweeters and severely damaged mid-range drivers.
Not really bogus. There are a few show-vans here with arrays of 8x 4 ohm subs which in parallel would give you .5 ohm load. Some have more than 8.
Never underestimate the boy racers in their search for bigger-is-better.
Their windows are screwed in place 😎
I did a lot of that too when I had an after school job installing car stereo in the 70s.
It was because the speaker distributors would only take returns if the voice coil was open. So when we had to replace a buzzing speaker it was subject to "the clip lead test" which applies 120VRMS from a wall outlet through a pair of clip leads to the speaker under test. Needless to say, no speaker ever passed (nay, survived) the clip lead test and all were sent back for return credit ;-)
Some definite 60Hz was audible, leading me to believe the speakers lasted for a few cycles (maybe 50-100 mS).
So this is like retardedness (is that a word ?) competition ?
"No, I'm the most retarded !"
"Nooo, my bus is shorter !!!!"
"Gaaah, I ate the spoon !!!!!1111!!oneone!!1"
"OK, you win if you eat this screwdriver!"
(no offense to those with genuine genetic disabilities; I'm one of them, albeit in another department)
Last edited:
Definitely possible, saw it in person in 2005 at dB Drag world finals. Alan Dante and what used to be a Volvo wagon 😛
As you mention, the vehicle is non-drivable at that point, interior gutted and re-built with maximum SPL in mind...panels and roof filled with concrete, lag bolts holding the doors closed, etc.
I know people who do 150dB with two 8" drivers 🙂
Last edited:
I'd rather see this kind of thing in a sanctioned competition, than people trying to do these setups in a vehicle driven every day...just like a car built for real drag racing, there's a time and a place for it.
While personally I don't think I'd put in that kind of time for something that plays a single frequency really loud, the technical side to it is interesting.
BINGO! I worked for Olson Electronics from 1970 to 1973 fixing just about anything electronic. I also installed car stereos, lots of Craig Pioneer 8 track units. We were located next to the University of Miami where lots of money was spent. If we sent anything back to Olson for warantee exchange it had better be dead, not just a little bit bad, DEAD! Most of the name brand stuff was warantee serviced in house.
I had one little guy pop the cone almost completely inverted. It looked cool. We sold some cheap two way 12 inch drivers that had a NP electrolytic for the crossover. The woofer would woof for about 2 cycles but the tweeter would sing the distortion, and noise on the power lines for several minutes until the crossover cap exploded.
No, I think like most competitions these days it is a "money spending" competition. He who spends the most is likely to win. At $25K for the amp, and who knows for the batteries and speakers, this game is not for the weak of wallet. I don't get it myself, but my parents didn't get most of what I did either.
Now for some more misadventures, Google LAN Parties. Here mostly young people spend over $5K on a tricked out water cooled multi core gaming computer, only to get caught up in the upgrade - rebuild - replace cycle to remain compettitive. The good side is that thanks to the innovation fueled by this spending, I can build a nice quad core computer that was state of the art last year for under $500 today.
- Status
- Not open for further replies.