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Vitopanch
Super Member
The beginnings of Infinity
Starting off this thread, I submit a couple of snipits concerning the beginnings of what turned out to be one of the major breakthrough companies in loudspeaker technology and which has brought so much sonic beauty to the dens and livingrooms throughout the world;
In 1967, Arnie Nudell, PhD. was at work designing the world's first Q-switched pulsed ruby laser to be used in a laser rangefinder that would measure accurately the distance between an airplane and the ground. A servo-feedback system would then be used to control the inertia navigation system of the airplane for accurate positioning. During his laboratory work, Arnie realized that such a servo system would be able to also accurately control a loudspeaker, hence, the idea of a servo-controlled woofer.
Together with John Ulrich, Arnie designed the servo system and power amplifier to drive a woofer. Arnie called another friend - Gene Czerwinski - to make a special 18-inch woofer with a second winding on the voice coil to produce the feedback signal. The system worked! And the world's first servo-controlled woofer was born.
Together with an electrostatic panel developed by another two aerospace engineers, and a cabinet designed and built by Cary Christie in his garage, the first product was built - the Servo Statik I. This was in 1968, and Infinity was founded. Through the 70's Infinity grew until it was acquired by Harman International.
In the 80's, Arnie launched what was to be the first real high-end loudspeaker with the Infinity Reference Standard - or IRS. It was not originally meant to be a commercial product, but to be a statement of the highest reference standard for sound reproduction. It was the first speaker to use the Electro Magnetic Induction Tweeter - the first ribbon tweeter, and featured a line source of tweeters and midrange ribbons in a dipole configuration. It also had a total of twelve 12-inch woofers controlled by dedicated servo amplifiers. Nevertheless, the IRS proved to be a runaway commercial success. Excepted from; http://www.genesisloudspeakers.com/...inghistory.html
John Ulrick’s account of the beginning;
We were supposed to be hard at work designing weapons systems for America - that's Arnie Nudell and me. Arnie and I worked at Litton Guidance & Control Systems in Woodland Hills, near L.A. We did build a weapons system, a laser rangefinder that measures the distance from an airplane to the ground for accurate bombing. We were also audiophiles, if there was such a term at the time. The year was 1967. I am an electronic engineer, Arnie a physicist. At Litton, my job was to design the electronics for the laser rangefinder and Arnie's was to design the world's first Q-switched pulsed ruby laser. This was the laser that supplied the pulse of light that went from the airplane to the "target" and bounced back, used to calculate the distance from the airplane to the target. Part of that system involved a mirror to point the laser beam at the target. I designed a servo-control system, which points the mirror and its switching amplifier. During lab testing of the servo-control system, Arnie noticed that the servo was controlling the mirror at 20Hz, a magic number to any audio person. Arnie had a good idea - why don't we make a servo-controlled woofer? We went across the hall to the Litton engineering library and found a book called Acoustical Engineering by Harry F. Olsen - the first bible of acoustics. The book had a page on Servo Controlled Speakers but no analysis, just a block diagram. We worked together to design the system. Arnie calculated the radiation resistance for the slopes and I designed the servo system and the power amplifier to drive the woofer. Arnie called his friend, Gene Czerwinski, to make a special 18-inch woofer with a second winding to generate the feedback signal. At the time Gene was an engineer at Bendix and making speakers in his garage. Gene later left Bendix to found Cerwin Vega. At this point one could wonder, who is making all these weapons systems? The woofer worked. There were two more aerospace engineers working at nearby Atomics International, Ron and Bob, making electrostatic panels. (The pentagon always said you must value the technology spin off from military research!) What a great combination, electrostatic panels that don't have much bass, coupled with an 18-inch servo-controlled woofer. The system was built and set up in Arnie's living room. Using a Sherwood amplifier to drive the electrostatic panels, the tweaking began. The amount of servo feedback changed. The crossover points moved and moved again.
Arnie and I decided to start a company. You could tell by the name there was no professional help in naming the company. The name was "Nutek" for Nudell Ulrick technology. We began selling a system called the "Servo-Static I" through a local dealer. The local dealer was about a mile from Litton and owned by Dr. Jim Henderson a physicist who you will hear more about later. All of this was still part time with a new guy involved, Cary Christie, a very talented industrial designer making the cabinetry in his garage. Arnie and I put out feelers to raise money and were finally backed by a rep firm that sold me electronic parts at Litton. No sophistication here either; we didn't even have a business plan because we didn't know what one was. A corporation was formed with Arnie and I holding equal interest. Fortunately, when we went to incorporate, the name Nutek was taken. The name Infinity was the third choice on the list, but available. The company name was Infinity, the year 1968. Again Arnie and I demonstrated our management prowess in choosing who was going to be the first president; we used the coin toss method. I was the president the first year and then we alternated for the first several years. What confusion! In August 1968 myself, Arnie and Cary and a couple of other people started full time in a 2,000 sq. ft. building in Chatsworth. Infinity was started. At the start, Infinity had three speakers; the Servo-Static I ($1800), the 2000, a bookshelf with electrostatic tweeters ($276) and the 1000, a 2 way bookshelf speaker. Excerpted from http://www.spectronav.com/tech2.htm
Vito
Starting off this thread, I submit a couple of snipits concerning the beginnings of what turned out to be one of the major breakthrough companies in loudspeaker technology and which has brought so much sonic beauty to the dens and livingrooms throughout the world;
In 1967, Arnie Nudell, PhD. was at work designing the world's first Q-switched pulsed ruby laser to be used in a laser rangefinder that would measure accurately the distance between an airplane and the ground. A servo-feedback system would then be used to control the inertia navigation system of the airplane for accurate positioning. During his laboratory work, Arnie realized that such a servo system would be able to also accurately control a loudspeaker, hence, the idea of a servo-controlled woofer.
Together with John Ulrich, Arnie designed the servo system and power amplifier to drive a woofer. Arnie called another friend - Gene Czerwinski - to make a special 18-inch woofer with a second winding on the voice coil to produce the feedback signal. The system worked! And the world's first servo-controlled woofer was born.
Together with an electrostatic panel developed by another two aerospace engineers, and a cabinet designed and built by Cary Christie in his garage, the first product was built - the Servo Statik I. This was in 1968, and Infinity was founded. Through the 70's Infinity grew until it was acquired by Harman International.
In the 80's, Arnie launched what was to be the first real high-end loudspeaker with the Infinity Reference Standard - or IRS. It was not originally meant to be a commercial product, but to be a statement of the highest reference standard for sound reproduction. It was the first speaker to use the Electro Magnetic Induction Tweeter - the first ribbon tweeter, and featured a line source of tweeters and midrange ribbons in a dipole configuration. It also had a total of twelve 12-inch woofers controlled by dedicated servo amplifiers. Nevertheless, the IRS proved to be a runaway commercial success. Excepted from; http://www.genesisloudspeakers.com/...inghistory.html
John Ulrick’s account of the beginning;
We were supposed to be hard at work designing weapons systems for America - that's Arnie Nudell and me. Arnie and I worked at Litton Guidance & Control Systems in Woodland Hills, near L.A. We did build a weapons system, a laser rangefinder that measures the distance from an airplane to the ground for accurate bombing. We were also audiophiles, if there was such a term at the time. The year was 1967. I am an electronic engineer, Arnie a physicist. At Litton, my job was to design the electronics for the laser rangefinder and Arnie's was to design the world's first Q-switched pulsed ruby laser. This was the laser that supplied the pulse of light that went from the airplane to the "target" and bounced back, used to calculate the distance from the airplane to the target. Part of that system involved a mirror to point the laser beam at the target. I designed a servo-control system, which points the mirror and its switching amplifier. During lab testing of the servo-control system, Arnie noticed that the servo was controlling the mirror at 20Hz, a magic number to any audio person. Arnie had a good idea - why don't we make a servo-controlled woofer? We went across the hall to the Litton engineering library and found a book called Acoustical Engineering by Harry F. Olsen - the first bible of acoustics. The book had a page on Servo Controlled Speakers but no analysis, just a block diagram. We worked together to design the system. Arnie calculated the radiation resistance for the slopes and I designed the servo system and the power amplifier to drive the woofer. Arnie called his friend, Gene Czerwinski, to make a special 18-inch woofer with a second winding to generate the feedback signal. At the time Gene was an engineer at Bendix and making speakers in his garage. Gene later left Bendix to found Cerwin Vega. At this point one could wonder, who is making all these weapons systems? The woofer worked. There were two more aerospace engineers working at nearby Atomics International, Ron and Bob, making electrostatic panels. (The pentagon always said you must value the technology spin off from military research!) What a great combination, electrostatic panels that don't have much bass, coupled with an 18-inch servo-controlled woofer. The system was built and set up in Arnie's living room. Using a Sherwood amplifier to drive the electrostatic panels, the tweaking began. The amount of servo feedback changed. The crossover points moved and moved again.
Arnie and I decided to start a company. You could tell by the name there was no professional help in naming the company. The name was "Nutek" for Nudell Ulrick technology. We began selling a system called the "Servo-Static I" through a local dealer. The local dealer was about a mile from Litton and owned by Dr. Jim Henderson a physicist who you will hear more about later. All of this was still part time with a new guy involved, Cary Christie, a very talented industrial designer making the cabinetry in his garage. Arnie and I put out feelers to raise money and were finally backed by a rep firm that sold me electronic parts at Litton. No sophistication here either; we didn't even have a business plan because we didn't know what one was. A corporation was formed with Arnie and I holding equal interest. Fortunately, when we went to incorporate, the name Nutek was taken. The name Infinity was the third choice on the list, but available. The company name was Infinity, the year 1968. Again Arnie and I demonstrated our management prowess in choosing who was going to be the first president; we used the coin toss method. I was the president the first year and then we alternated for the first several years. What confusion! In August 1968 myself, Arnie and Cary and a couple of other people started full time in a 2,000 sq. ft. building in Chatsworth. Infinity was started. At the start, Infinity had three speakers; the Servo-Static I ($1800), the 2000, a bookshelf with electrostatic tweeters ($276) and the 1000, a 2 way bookshelf speaker. Excerpted from http://www.spectronav.com/tech2.htm
Vito
Vitopanch
Super Member
The temporary loss of vision during the Harmon Takeover
Here is a snipit talking about the Harmon buyout of Infinity Corp;
Sometimes you have to wonder why big corporations gobble up small speaker companies. Most such firms are built by individualist entrepreneurs chasing an elusive dream—an up-close and personal thing that is the antithesis of the corporate mentality. That's why speaker companies are so often named after the founder.
The company builds a solid reputation and is then bought out, and for a while, momentum carries the day. But then, unless whomever is brought onboard to engineer new designs can carry the dream forward with products that are innovative yet maintain the franchise's distinctive personality, the brand slides into eventual oblivion.
When Harman International bought Infinity from Arnie Nudell and Cary Christie in the early '90s, it bought a solid brand name that was familiar to consumers outside of the specialty audio world. It bought significant, innovative technologies, including one of the first servo-controlled subwoofers, the EMIT ribbon tweeter, and the EMIM ribbon midrange unit.
It also bought a line of speakers that included the RS-1 series, one of the most well-regarded audiophile loudspeakers of the 1980s; and the flagship IRS, considered at the time of acquisition to be among the finest speakers in the world, and one guaranteed to get coverage in Playboy, The Robb Report, and other publications read by non-audiophiles. Fabio owns two pairs. I heard them when I worked for The Abso!ute Sound, and while Harry Pearson often had the bass turned up too much for my tastes, when everything was right that four-monolith giant could seem to disappear, leaving music on a symphonic scale.
Perhaps Harman felt the Infinity name alone was worth the purchase price, if only to use as an OEM brand in the then-developing and lucrative market of car audio. As a hedge against making a bad business bet, that certainly worked out in Harman's favor, but it was clear to anyone who followed the Infinity brand after the acquisition that Harman desired to maintain the line's luster.
Yet the brand name seemed to flounder for a while as Infinity's speakers didn't catch fire with the core audiophile market. Then someone made the decision to carefully rebuild the Infinity franchise as a premier line of innovative loudspeakers. Serious corporate assets were invested in design talent and technology.
With the introduction of Compositions in 1995, the investment paid off. A precursor to the Prelude MTS loudspeaker under review here, the Composition Prelude PF-R (very favorably reviewed in the September 1995 Stereophile, Vol.18 No.9) was a truly original design in the Infinity tradition. It put Infinity back on the map as a serious player in the specialty audio market. Excerpted from http://www.stereophile.com/loudspeakerreviews/295/
Vito
Here is a snipit talking about the Harmon buyout of Infinity Corp;
Sometimes you have to wonder why big corporations gobble up small speaker companies. Most such firms are built by individualist entrepreneurs chasing an elusive dream—an up-close and personal thing that is the antithesis of the corporate mentality. That's why speaker companies are so often named after the founder.
The company builds a solid reputation and is then bought out, and for a while, momentum carries the day. But then, unless whomever is brought onboard to engineer new designs can carry the dream forward with products that are innovative yet maintain the franchise's distinctive personality, the brand slides into eventual oblivion.
When Harman International bought Infinity from Arnie Nudell and Cary Christie in the early '90s, it bought a solid brand name that was familiar to consumers outside of the specialty audio world. It bought significant, innovative technologies, including one of the first servo-controlled subwoofers, the EMIT ribbon tweeter, and the EMIM ribbon midrange unit.
It also bought a line of speakers that included the RS-1 series, one of the most well-regarded audiophile loudspeakers of the 1980s; and the flagship IRS, considered at the time of acquisition to be among the finest speakers in the world, and one guaranteed to get coverage in Playboy, The Robb Report, and other publications read by non-audiophiles. Fabio owns two pairs. I heard them when I worked for The Abso!ute Sound, and while Harry Pearson often had the bass turned up too much for my tastes, when everything was right that four-monolith giant could seem to disappear, leaving music on a symphonic scale.
Perhaps Harman felt the Infinity name alone was worth the purchase price, if only to use as an OEM brand in the then-developing and lucrative market of car audio. As a hedge against making a bad business bet, that certainly worked out in Harman's favor, but it was clear to anyone who followed the Infinity brand after the acquisition that Harman desired to maintain the line's luster.
Yet the brand name seemed to flounder for a while as Infinity's speakers didn't catch fire with the core audiophile market. Then someone made the decision to carefully rebuild the Infinity franchise as a premier line of innovative loudspeakers. Serious corporate assets were invested in design talent and technology.
With the introduction of Compositions in 1995, the investment paid off. A precursor to the Prelude MTS loudspeaker under review here, the Composition Prelude PF-R (very favorably reviewed in the September 1995 Stereophile, Vol.18 No.9) was a truly original design in the Infinity tradition. It put Infinity back on the map as a serious player in the specialty audio market. Excerpted from http://www.stereophile.com/loudspeakerreviews/295/
Vito
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Vitopanch
Super Member
Hey folks. Junkaudio provided us with this entertaining and informative interview of Mister Nudell.
Originally Posted by junkaudio
here is a livestream interview with mr. nudell !!
http://www.hometheaterhifi.com/vide...2004-arnie-nudell-genesis-speakers-index.html
Originally Posted by junkaudio
here is a livestream interview with mr. nudell !!
http://www.hometheaterhifi.com/vide...2004-arnie-nudell-genesis-speakers-index.html
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Kencat
Super Member
More on John Ulrich
An excerpt from http://www.gcaudio.com/products/reviews/infospectron2.html
"Likely no one has spent as much time on attaining this goal as John Ulrick, founder of Spectron. Since the early 1970’s John has been experimenting with and refining the techniques required to build an all-digital power amplifier for audio. A bit of background is in order.
In 1968 John Ulrick co-founded Infinity Systems (the speaker company) with Arnie Nudell. Together, Nudell (a physicist) and Ulrick (an electrical engineer), soon built a name for themselves with their speakers.
Shortly after Infinity’s inception, John began working on a digital amplifier for audio applications. A great deal of research and development went into the project, finally culminating in the release of the World’s first digital switching amplifier. Infinity sold several hundred of these early designs, a 125 watt unit known as the SWAMP 1.
In 1979 John sold his interest in Infinity Systems to pursue other avenues. Though on the back burner (while other pursuits paid the bills), John continued his commitment to further refine digital amplification. Eventually, Spectron was born."
Read more about this Spectron - lots of power to drive some of the ..ummm.....more difficult Infinities.
An excerpt from http://www.gcaudio.com/products/reviews/infospectron2.html
"Likely no one has spent as much time on attaining this goal as John Ulrick, founder of Spectron. Since the early 1970’s John has been experimenting with and refining the techniques required to build an all-digital power amplifier for audio. A bit of background is in order.
In 1968 John Ulrick co-founded Infinity Systems (the speaker company) with Arnie Nudell. Together, Nudell (a physicist) and Ulrick (an electrical engineer), soon built a name for themselves with their speakers.
Shortly after Infinity’s inception, John began working on a digital amplifier for audio applications. A great deal of research and development went into the project, finally culminating in the release of the World’s first digital switching amplifier. Infinity sold several hundred of these early designs, a 125 watt unit known as the SWAMP 1.
In 1979 John sold his interest in Infinity Systems to pursue other avenues. Though on the back burner (while other pursuits paid the bills), John continued his commitment to further refine digital amplification. Eventually, Spectron was born."
Read more about this Spectron - lots of power to drive some of the ..ummm.....more difficult Infinities.
The '95 issue of Stereophile with all the Infinity info is available on the Yahoo 'Infinity Classics' site. Hopefully, this link I'll post will be a shortcut to get there for you. The Epsilon is on the cover and the Renaissance is mentioned briefly by Cary Christie (these are two of the best loudspeakers ever made)
http://f2.grp.yahoofs.com/v1/4PcuRF...Kl/stereophile0195-nudell-christie-ulrich.pdf
http://f2.grp.yahoofs.com/v1/4PcuRF...Kl/stereophile0195-nudell-christie-ulrich.pdf
In The summer of 1976, a salesman at an audio store told me he had seen a digital amp made by a company called "Infinity" at a electronics products convention in Chicago. He said "the amp was over 100 watts and could be held on one hand". Of course I asked him a bunch of questions; how did it work; what about the temperature; how did it sound? He answered as best as he could and I left in awe.
Later in the spring of 1977, the audio store, where the salesman worked, had a large
sale of audio equipment, so I and a friend dropped in to see what was new. There was
the salesman and he showed us the Infinity digital pre-amp for $2000 dollars, the power amp was nowhere around. So we left not hearing either one of them, still the memory of the 100 watt amp that could be held in one hand lingers on.
Later in the spring of 1977, the audio store, where the salesman worked, had a large
sale of audio equipment, so I and a friend dropped in to see what was new. There was
the salesman and he showed us the Infinity digital pre-amp for $2000 dollars, the power amp was nowhere around. So we left not hearing either one of them, still the memory of the 100 watt amp that could be held in one hand lingers on.
Last edited:
Kencat
Super Member
Here's an excerpt from http://www.positive-feedback.com/pfbackissues/0604/pappas.spectron.6n4.html
(Note: John Ulrick is narrating the following)
"As time allowed, I started working on a digital switching amplifier based on my switching amplifier experience at Litton. Later my friend Dr. Jim Henderson, now a physicist at Hughes, joined in on the work. With Jim analyzing and me circuit designing, work progressed. Designing the power switching section with the parts available in the mid ‘70s was a real trick. I used power transistors from TRW which were very expensive. On a good day I could go through $200 worth of them. About a year before the winter CES show in Chicago we naively committed to showing a digital switching amplifier. As the show grew closer, the Infinity gang heard Bose was going to show a switching amplifier. Not wanting to end up second, we pressed on to get a working amplifier ready for the show. For the last three months of October, November and December several people worked straight through, no days off. We spent Christmas morning with our families and met at Infinity in the early afternoon on Christmas day and had the Rose Bowl game on in the lab on New Year’s day.
The first day of the show was about Jan 7th. I had airline tickets to fly to Chicago a couple of days before the show opened, but the amplifier wasn’t working. Finally, the night before the show, the amplifier was working, but the displays were making a ticking sound. Finally we just disconnected them, listened to the amp for about 15 minutes in the sound room and I caught the last flight that would make the show. I was picked up at the airport at 7 a.m. and rushed to the show. With my coat draped over it, I carried the amplifier past the line of press people waiting outside our room to see an amplifier they thought was in that room. We set it up and it worked! The doors opened at 9 a.m. and we showed the first digital switching amplifier ever. It was 125 watts per channel and ran flawlessly for the four days of the show. Bose didn’t show up with a switching amp — thanks!
Following the show, the amplifier was made production-ready and sold as the SWAMP I, a 250 watt per channel amplifier. The name SWAMP came from one of Jim Henderson’s computer programs with the file name SWAMP. Infinity sold a few hundred of them. Arnie and I sold our interest in Infinity and I left in 1979. Arnie stayed on as President till about 1990, when he left to start Genesis. Well, Infinity’s part of Harman now; they sell through those big chain stores, and the new gang even wears ties to work.
More fun. I had the opportunity to head up a new hi tech company, set up to develop a video multiplexer that allowed the transmission of two TV programs over a single satellite channel with a bunch of guys I loved working with, including Jack with 125+ patents, and Dr. Jim. Big mistake! By the time we completed the research, got all kinds of patents and licensed the thing to a big broadcast equipment company, MPEG had become the standard.
After some time running a computer company and an avionics company to make sure that wasn’t what I wanted to do, I started Spectron and began work on a new generation of digital/switching amplifiers. I have always believed in them. It took three years of very long hours. My 600 hp fuel injected drag boat’s deck has been used as a table and my Lotus formula Atlantic race car is just waiting to go racing. On the design side, one thing that sure has been a big help this time is all the computer aided math, PCB layout, drafting and simulation; MathCAD, AutoCAD, all that stuff.
It seems to have worked out. Enough people really like the sound, and unlike the Infinity amp, they are very reliable. (The addition of four diodes fixes the Infinity amp — wish I knew that then.) And they are small and light. Even back at Infinity I envisioned a one kilowatt amplifier.
Conceptually, digital amplifiers are simple. You just keep sending pulses of energy alternately from the plus rail and then the minus rail into the speaker and have a feedback circuit to control all these bundles of energy coming from the plus and minus rails. Controlling the voltage at the speaker is like guiding a hockey puck on the ice. First you push from the left and then from the right and you are always making corrections as you guide the puck along the ice. The digital amp gets interesting because you do this 500,000 times a second, so the digital circuits to control corrections must be very fast.
Conceptually, the digital amps are the way to go. They use virtually no analog circuitry (except the input buffer). This eliminates nearly all the analog gain stages, which are inherently slow, each adding a small amount of distortion and delay. It’s the slowness of analog circuitry that diminishes the benefits of loop feedback, resulting in an undesirable effect on the sound. In Spectron’s digital amp, the audio is converted into a digital signal at the input. From that point on it’s processed in high speed digital logic (TTL). The output section involves two FET switches, an inductor and a couple of capacitors which are not in the signal path. If the switches were perfect, with zero turn ON and OFF times, no ON resistance and the logic had no delays, the amp would be perfect. Of course, none of the parts are perfect, but they are getting closer every year.
If all goes well, next time you hear from me, about all I’ll have to say is the amps are working great, they just keep going out the door and ya, I’ve got time to do lunch."
My impression is that the Swamp was not too good.....prototype phase it would seem. The later development by J Ulrick, the Spectron, is probably more significant. But then, to have a piece of history, aka a Swamp 1....wouldn't that be something :yes:
For those who haven't read the links yet, here are the specs on the Spectron Musician III, a descendent of the Swamp 1:
"Technical Specifications • Power Watts per channel, both channels driven
600 watts at 8 ohms
800 watts at 4 ohms
1400 watts at 2 ohms • Peak current 50 amps •"
I think my Quantum 2s would appreciate that ....yhaaa..... I think so. :thmbsp:
(Note: John Ulrick is narrating the following)
"As time allowed, I started working on a digital switching amplifier based on my switching amplifier experience at Litton. Later my friend Dr. Jim Henderson, now a physicist at Hughes, joined in on the work. With Jim analyzing and me circuit designing, work progressed. Designing the power switching section with the parts available in the mid ‘70s was a real trick. I used power transistors from TRW which were very expensive. On a good day I could go through $200 worth of them. About a year before the winter CES show in Chicago we naively committed to showing a digital switching amplifier. As the show grew closer, the Infinity gang heard Bose was going to show a switching amplifier. Not wanting to end up second, we pressed on to get a working amplifier ready for the show. For the last three months of October, November and December several people worked straight through, no days off. We spent Christmas morning with our families and met at Infinity in the early afternoon on Christmas day and had the Rose Bowl game on in the lab on New Year’s day.
The first day of the show was about Jan 7th. I had airline tickets to fly to Chicago a couple of days before the show opened, but the amplifier wasn’t working. Finally, the night before the show, the amplifier was working, but the displays were making a ticking sound. Finally we just disconnected them, listened to the amp for about 15 minutes in the sound room and I caught the last flight that would make the show. I was picked up at the airport at 7 a.m. and rushed to the show. With my coat draped over it, I carried the amplifier past the line of press people waiting outside our room to see an amplifier they thought was in that room. We set it up and it worked! The doors opened at 9 a.m. and we showed the first digital switching amplifier ever. It was 125 watts per channel and ran flawlessly for the four days of the show. Bose didn’t show up with a switching amp — thanks!
Following the show, the amplifier was made production-ready and sold as the SWAMP I, a 250 watt per channel amplifier. The name SWAMP came from one of Jim Henderson’s computer programs with the file name SWAMP. Infinity sold a few hundred of them. Arnie and I sold our interest in Infinity and I left in 1979. Arnie stayed on as President till about 1990, when he left to start Genesis. Well, Infinity’s part of Harman now; they sell through those big chain stores, and the new gang even wears ties to work.
More fun. I had the opportunity to head up a new hi tech company, set up to develop a video multiplexer that allowed the transmission of two TV programs over a single satellite channel with a bunch of guys I loved working with, including Jack with 125+ patents, and Dr. Jim. Big mistake! By the time we completed the research, got all kinds of patents and licensed the thing to a big broadcast equipment company, MPEG had become the standard.
After some time running a computer company and an avionics company to make sure that wasn’t what I wanted to do, I started Spectron and began work on a new generation of digital/switching amplifiers. I have always believed in them. It took three years of very long hours. My 600 hp fuel injected drag boat’s deck has been used as a table and my Lotus formula Atlantic race car is just waiting to go racing. On the design side, one thing that sure has been a big help this time is all the computer aided math, PCB layout, drafting and simulation; MathCAD, AutoCAD, all that stuff.
It seems to have worked out. Enough people really like the sound, and unlike the Infinity amp, they are very reliable. (The addition of four diodes fixes the Infinity amp — wish I knew that then.) And they are small and light. Even back at Infinity I envisioned a one kilowatt amplifier.
Conceptually, digital amplifiers are simple. You just keep sending pulses of energy alternately from the plus rail and then the minus rail into the speaker and have a feedback circuit to control all these bundles of energy coming from the plus and minus rails. Controlling the voltage at the speaker is like guiding a hockey puck on the ice. First you push from the left and then from the right and you are always making corrections as you guide the puck along the ice. The digital amp gets interesting because you do this 500,000 times a second, so the digital circuits to control corrections must be very fast.
Conceptually, the digital amps are the way to go. They use virtually no analog circuitry (except the input buffer). This eliminates nearly all the analog gain stages, which are inherently slow, each adding a small amount of distortion and delay. It’s the slowness of analog circuitry that diminishes the benefits of loop feedback, resulting in an undesirable effect on the sound. In Spectron’s digital amp, the audio is converted into a digital signal at the input. From that point on it’s processed in high speed digital logic (TTL). The output section involves two FET switches, an inductor and a couple of capacitors which are not in the signal path. If the switches were perfect, with zero turn ON and OFF times, no ON resistance and the logic had no delays, the amp would be perfect. Of course, none of the parts are perfect, but they are getting closer every year.
If all goes well, next time you hear from me, about all I’ll have to say is the amps are working great, they just keep going out the door and ya, I’ve got time to do lunch."
My impression is that the Swamp was not too good.....prototype phase it would seem. The later development by J Ulrick, the Spectron, is probably more significant. But then, to have a piece of history, aka a Swamp 1....wouldn't that be something :yes:
For those who haven't read the links yet, here are the specs on the Spectron Musician III, a descendent of the Swamp 1:
"Technical Specifications • Power Watts per channel, both channels driven
600 watts at 8 ohms
800 watts at 4 ohms
1400 watts at 2 ohms • Peak current 50 amps •"
I think my Quantum 2s would appreciate that ....yhaaa..... I think so. :thmbsp:
Last edited:
Kencat
Super Member
plhart at AVS forum:
Arnie Nudell and my long-time friend John Ulrick were the two co-founders of Infinity (see the true Infinity story “About Us” at www.spectronav.com ). Cary Christie was a very talented cabinet maker to whom Arnie and John turned to make the cabinets for their first speaker, the Servo-Static One. Cary is now the president of Artison speakers.
Infinity was sold to Harman in 1979 but Arnie stayed on as President, working under the Harman tent until 1990.
Last I heard Infinity speakers today are made in either Taiwan/China by subcontractors (Primus) or in Harman’s Tijuana, Mexico facility (Beta) as they were when I was there 4.5 years ago.
Dr. Floyd Toole retired and left Harman 1.5 years ago and the famed Multichannel Listening Lab were we speaker engineers listened double-blind to each other’s creations has been assigned to the Harman-Becker Car Audio Division. So my understanding is that the Lab is seldom used nowadays to compare upcoming models against either past Infinity/JBL/Harman speakers or the competition (as had always been a prerequisite on the road to final approval for production).
Infinity’s 20 year sales manager left for Boston Acoustics (owned by D & M Holdings) two years ago as has Gena Harman (past President of the Harman Consumer Division). Plus, Harman International just recently had the sale of itself fall through. So, is it any wonder that the famed Infinity presence on the retail scene has been greatly diminished?
Arnie Nudell and my long-time friend John Ulrick were the two co-founders of Infinity (see the true Infinity story “About Us” at www.spectronav.com ). Cary Christie was a very talented cabinet maker to whom Arnie and John turned to make the cabinets for their first speaker, the Servo-Static One. Cary is now the president of Artison speakers.
Infinity was sold to Harman in 1979 but Arnie stayed on as President, working under the Harman tent until 1990.
Last I heard Infinity speakers today are made in either Taiwan/China by subcontractors (Primus) or in Harman’s Tijuana, Mexico facility (Beta) as they were when I was there 4.5 years ago.
Dr. Floyd Toole retired and left Harman 1.5 years ago and the famed Multichannel Listening Lab were we speaker engineers listened double-blind to each other’s creations has been assigned to the Harman-Becker Car Audio Division. So my understanding is that the Lab is seldom used nowadays to compare upcoming models against either past Infinity/JBL/Harman speakers or the competition (as had always been a prerequisite on the road to final approval for production).
Infinity’s 20 year sales manager left for Boston Acoustics (owned by D & M Holdings) two years ago as has Gena Harman (past President of the Harman Consumer Division). Plus, Harman International just recently had the sale of itself fall through. So, is it any wonder that the famed Infinity presence on the retail scene has been greatly diminished?