Variac said:Nelson seems more like a genie than a god.
You have to be VERY careful how you parse your request.
We ask for a huge amp (thinking 500-1000 w/ch)
and we get a 15 KW amp proposal!!
Yes i have noticed that. Im not the one that started this request. i just picked up on it recently!! I just restarted the quest!
I dont know how we got off into mega kilowatt amp design. But it has been fun so far.... Im hoping this megawatt dreaming is a byproduct of some actuall KW amp design thats happening!
I think Mr. Pass is poking some fun at us too! But wouldnt it be fun to see a pass X30,000 !!!! hahahahaha
That seems to be the trend these days, super sized amps! Both Ampeg and Crate built HUGE guitar amps at a recent show. and i MEAN HUGE!!!!! I wish i still had that link available....
Jeeze just think of the bank of capacitors we would need for a sub 30Kw amp!!!!
I think the Amp God should design and build ONE super sized monster just to compete with his K-Brand counterpart! Maybe that has been the motivation behind this all along eh?
BTW, that brings up a good point, what is the minimum reccomended amount of capacitance for a 1KW amp anyway???
Zero
Nelson Pass said:Well, the X1000 does a kilowatt into 8 ohms and uses 8 X 25,000
uF caps. I has the merit of only two gain stages (a cascoded
input differential pair and a push-pull follower) and works quite
well.
How about the most powerful single-stage amp we can
reasonably build?
Dont make me have to build a Holtan!!!!!
Zero
Hmmm Single gain stage mega_Watt amp? I think we need to parralel devices and make use of a Complementair-Feedback-Pair.. but is that considered as a single gain stage?
We could offcourse make a diff-pair with active current source, aleph drain-loads, and x-feedback... but again I went for the simplest....
I made up this zenish variation, that alows class B drive beyond the class A bias point... will do >250Watt in to 8 ohm...
We could offcourse make a diff-pair with active current source, aleph drain-loads, and x-feedback... but again I went for the simplest....
I made up this zenish variation, that alows class B drive beyond the class A bias point... will do >250Watt in to 8 ohm...
This thread reminded me of an amplifier I saw in a shop once,about 10 years ago.. (Audio Specialties on Portland,Or..cool shop,and nice enough guys,they do decent work too.) A friend and I wandered in one day and were looking around,and on the far wall was this fairly normal looking piece (19" 3U tall I think) with the exception of "19,000Watts" printed on the front,along with a power switch..nothing else..
I turned and asked the guy at the counter if this was *really* a 19KW amp.."yea" ,he went on to say he had just bought it from a guy in a well known band. (I forget who now..)
My Friend and I were talking about that for weeks! (we were..~13yo at the time..)
I turned and asked the guy at the counter if this was *really* a 19KW amp.."yea" ,he went on to say he had just bought it from a guy in a well known band. (I forget who now..)
My Friend and I were talking about that for weeks! (we were..~13yo at the time..)
"We could wire them point to point with 8 ga."
Actually silver plated OFC buss bar might be a better choice if the output terminals happened to short circuit the 8 ga might just melt down. There are high power Xenon switching rectifiers that use that exact transistor. These are common place in theatres today and they run lamps up to 15kw 15/70 format in size(three units paralleled). Thats about 450 amps and 32 volts. These things run day in and day out and are rarely shut down during the operating day. They give very little to no trouble at all and only weigh about 70 lbs each.
Years ago BGW Systems made an amp called the "Arc Welders Special " It was capable of actually doing a welding job as was evedinced in some review I remember seeing about it in which the reviewer actually welded together two pieces of steel of some sort . That amp used a cooling tunnel arrangement to good advantage.
Mark
Actually silver plated OFC buss bar might be a better choice if the output terminals happened to short circuit the 8 ga might just melt down. There are high power Xenon switching rectifiers that use that exact transistor. These are common place in theatres today and they run lamps up to 15kw 15/70 format in size(three units paralleled). Thats about 450 amps and 32 volts. These things run day in and day out and are rarely shut down during the operating day. They give very little to no trouble at all and only weigh about 70 lbs each.
Years ago BGW Systems made an amp called the "Arc Welders Special
" It was capable of actually doing a welding job as was evedinced in some review I remember seeing about it in which the reviewer actually welded together two pieces of steel of some sort . That amp used a cooling tunnel arrangement to good advantage.Mark
highbias said:[B Years ago BGW Systems made an amp called the "Arc Welders Special
Mark [/B]
Audio or High Fidelity Magazine did this with a pair of Mark Levinson Amps years ago. they connected the pair together through a resistor series block and drove them with a 1Khz square wave and welded 2 pieces of .05 ga steel together using the speaker outputs and a piece of welding rod!!!
The reviewer went on to say that it made a nice plasma tweeter and hearing protection had to be used. the amps were then run through the gamut of usuall audio tests then listened too and virtually no difference was heard before or after the welding test.
Zero
I've borrowed 400W/ch amps from work (almost their smallest) and found that kind of power in my livingroom to be more than adequate (perhaps like driving a Dodge Viper in a parking garage).
I asked about their AP6040, the designer smiled and suggested keeping a fire extinguisher handy, for the speakers.
I only mention this because I wonder who has the space to get far enough away from their speakers to listen to big watts?!
I asked about their AP6040, the designer smiled and suggested keeping a fire extinguisher handy, for the speakers.
I only mention this because I wonder who has the space to get far enough away from their speakers to listen to big watts?!
I am tempted to compare inefficiency in a speaker to inefficiency in an amplifer... a class A might be less than 5% efficient, compared to a class D that is 95% efficient. Which one sounds better?
However, dissipating a lot of heat seems to be much more detrimental to the sound of a speaker than to the sound of an amplifier. Things that affect the motor strength and linearity are increased with power level; i hear that some types of distortion go up with the cube of the power. I'm not so knowledgeable of that.
It seems to me that the REAL reason I'd want a kilowatt amplifier would be so that I could have loud, deep bass from a small sealed box. Imagine a couple of sealed 16" cubes in your room- each with a Tumult and a linkwitz transform... those things could really drink up the juice!
Somebody please correct me if I'm on the wrong track, but I really think that the point of a kilowatt+ amp in your home is BASS, not sparkling highs.
However, dissipating a lot of heat seems to be much more detrimental to the sound of a speaker than to the sound of an amplifier. Things that affect the motor strength and linearity are increased with power level; i hear that some types of distortion go up with the cube of the power. I'm not so knowledgeable of that.
It seems to me that the REAL reason I'd want a kilowatt amplifier would be so that I could have loud, deep bass from a small sealed box. Imagine a couple of sealed 16" cubes in your room- each with a Tumult and a linkwitz transform... those things could really drink up the juice!
Somebody please correct me if I'm on the wrong track, but I really think that the point of a kilowatt+ amp in your home is BASS, not sparkling highs.
I want a larger amp not so i can play it louder, so i wont clip on transients!.
I have a large listening room and my Speakers are very power hungry! with a 4 ohm impedance and a 86dB 1 watt sensitivity, it takes some juice to get em up and running. there are spots where the impedance curve dips down around 2 ohms or lower.
I like dynamic music and movies. every time i play the Dallas Wind Symphony, or Bella Fleck, or Crystal Method. my clip lights flash!
My amp is rated at 205/300 @ 8/4 and thats just not enough..
400/800 would be more then sufficient to keep the same volume level, but not clip on the transients.
For example, the Banjo plucks on Flight of the Cosmic Hippo by Bella Fleck will clip when played at a high, but reasonable volume level.
Plus my amp lacks bass strength. swapping in a Bryston 4B into my system adds an entire octave to the low end LITERALLY. So im quite sure my little amp just doesnt have the current to drive my speakers like the Bryston does...
Thats why i want a larger amp. not to play louder, but to have the current and control my speakers are demanding with an extra degree of headroom. and lets face it, a jump from 300 to 800 watts ads what, 4-5dB max? It will not be all that much louder then it is now!
AND, such a design would lend itself to many other applications as well. For example, my recording studio needs a new amp for the main monitors. With double 15's per cabinet and loud rock music (i work with rock bands) the 4B runs out of power right away. More power is definitly needed there....
1KW amps would lend themselfs well to duty with the band running our Double 18" sub bins of which we have 8 of!
And yes, i would like to build a large sub for the listening room someday and a nice 800-1Kw amp would be nice for that as well!
I had hoped to entice Mr. Pass to do something akin to a reunion tour and bring back a 2005 version of something similar to the A75. Hey it seems to be working for the Rolling Stones, Bob Dylan, Eric Clapton, McCartney and Wings, and just about every other 60-70 major act!
And who wouldnt want to see something as such from the man himself???
Personally i think it would be fascinating to take a drive down that path again and revisit such a design with everything that has been learned so far!
Heck i have more then 75 watts running my Garage speakers!!!
And if i am going to invest the kind of money it takes to build an amp. then i would like to build something i can actually use. not something that will sit in the closet for the rest of its life!
Oh well... The dream was nice.
Zero
I have a large listening room and my Speakers are very power hungry! with a 4 ohm impedance and a 86dB 1 watt sensitivity, it takes some juice to get em up and running. there are spots where the impedance curve dips down around 2 ohms or lower.
I like dynamic music and movies. every time i play the Dallas Wind Symphony, or Bella Fleck, or Crystal Method. my clip lights flash!
My amp is rated at 205/300 @ 8/4 and thats just not enough..
400/800 would be more then sufficient to keep the same volume level, but not clip on the transients.
For example, the Banjo plucks on Flight of the Cosmic Hippo by Bella Fleck will clip when played at a high, but reasonable volume level.
Plus my amp lacks bass strength. swapping in a Bryston 4B into my system adds an entire octave to the low end LITERALLY. So im quite sure my little amp just doesnt have the current to drive my speakers like the Bryston does...
Thats why i want a larger amp. not to play louder, but to have the current and control my speakers are demanding with an extra degree of headroom. and lets face it, a jump from 300 to 800 watts ads what, 4-5dB max? It will not be all that much louder then it is now!
AND, such a design would lend itself to many other applications as well. For example, my recording studio needs a new amp for the main monitors. With double 15's per cabinet and loud rock music (i work with rock bands) the 4B runs out of power right away. More power is definitly needed there....
1KW amps would lend themselfs well to duty with the band running our Double 18" sub bins of which we have 8 of!
And yes, i would like to build a large sub for the listening room someday and a nice 800-1Kw amp would be nice for that as well!
I had hoped to entice Mr. Pass to do something akin to a reunion tour and bring back a 2005 version of something similar to the A75. Hey it seems to be working for the Rolling Stones, Bob Dylan, Eric Clapton, McCartney and Wings, and just about every other 60-70 major act!
And who wouldnt want to see something as such from the man himself???
Personally i think it would be fascinating to take a drive down that path again and revisit such a design with everything that has been learned so far!
Heck i have more then 75 watts running my Garage speakers!!!
And if i am going to invest the kind of money it takes to build an amp. then i would like to build something i can actually use. not something that will sit in the closet for the rest of its life!
Oh well... The dream was nice.
Zero
Anybody clipping a 300W/4ohm amp isn't exactly what you'd call in the target audience for a "normal" Zen.
Nelson, your task has now been made easier, however. If it's 1kW he seeks, you only have to develop a 500W amp (into 8 ohms). His speakers will do the rest...assuming that the bias and power supply are up to the task.
Zero,
Don't set your hopes on "lotsa power" equalling "more bass" as there are many more factors involved in bass reproduction than mere wattage. In fact, I'd put power way down the list in importance. The negative feedback ratio, for instance, has an effect. Also, the size of the power supply; it's amazing how much more bass you can get out of an amp simply by increasing the amount of capacitance in the power supply.
Not that you can't run hi-fi amps in a PA system--it's been done many times--but the benefits are frequently lost. For the most part, pro amps have tiny power supplies that would disgust any self-respecting audio nut. For example, my Ampeg SVT (tubes, 300W) has something like 2-300uF in the power supply. Jeez, that's barely enough for a 20W stereo amp. From the other side of the fence, my old Conrad Johnson Premier One (tubes, either 200 or 250W, depending on who was quoting the numbers), had 1650uF per channel (two 3300uF caps in series). Which one had more dynamics? More bass?
Huh.
Friend of mine bought a pair of those Hurricane amps (tubes, 200W). Decent enough circuit, but I nearly had a heart attack when I saw how tiny the power supply was. I'm currently on a campaign to get him to put more capacitance in.
I'm not trying to talk you out of a new amp--just urging you to keep your expectations reasonable.
Incidentally, be careful if you decide to beef up the power supply in a pro amp. Speakers can't take the kind of dynamics that result from a large power supply; they don't have sufficient Xmax. You have been warned.
Grey
P.S.: Anyone want to buy an absolutely mint mid-seventies Ampeg SVT? It's in such good condition that I'm informed that the Orion Bluebook folks came by and took a picture of it at the Texas guitar show a week or two ago.
Nelson, your task has now been made easier, however. If it's 1kW he seeks, you only have to develop a 500W amp (into 8 ohms). His speakers will do the rest...assuming that the bias and power supply are up to the task.
Zero,
Don't set your hopes on "lotsa power" equalling "more bass" as there are many more factors involved in bass reproduction than mere wattage. In fact, I'd put power way down the list in importance. The negative feedback ratio, for instance, has an effect. Also, the size of the power supply; it's amazing how much more bass you can get out of an amp simply by increasing the amount of capacitance in the power supply.
Not that you can't run hi-fi amps in a PA system--it's been done many times--but the benefits are frequently lost. For the most part, pro amps have tiny power supplies that would disgust any self-respecting audio nut. For example, my Ampeg SVT (tubes, 300W) has something like 2-300uF in the power supply. Jeez, that's barely enough for a 20W stereo amp. From the other side of the fence, my old Conrad Johnson Premier One (tubes, either 200 or 250W, depending on who was quoting the numbers), had 1650uF per channel (two 3300uF caps in series). Which one had more dynamics? More bass?
Huh.
Friend of mine bought a pair of those Hurricane amps (tubes, 200W). Decent enough circuit, but I nearly had a heart attack when I saw how tiny the power supply was. I'm currently on a campaign to get him to put more capacitance in.
I'm not trying to talk you out of a new amp--just urging you to keep your expectations reasonable.
Incidentally, be careful if you decide to beef up the power supply in a pro amp. Speakers can't take the kind of dynamics that result from a large power supply; they don't have sufficient Xmax. You have been warned.
Grey
P.S.: Anyone want to buy an absolutely mint mid-seventies Ampeg SVT? It's in such good condition that I'm informed that the Orion Bluebook folks came by and took a picture of it at the Texas guitar show a week or two ago.
It's an interesting observation that you can't necessarily predict
the bass sound from the spec sheet. Years ago I would have
assumed that it was an issue of power and output impedance,
but I've seen too many counter examples.
It appears that lots of hardware definitely helps, but damping
factor is not what it's supposed to have been.
Maybe a Zen could be the proof of that......
the bass sound from the spec sheet. Years ago I would have
assumed that it was an issue of power and output impedance,
but I've seen too many counter examples.
It appears that lots of hardware definitely helps, but damping
factor is not what it's supposed to have been.
Maybe a Zen could be the proof of that......
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.