I watched this entire series from start to finish, what a beautiful amp and you did a great job on it. You often exceed some very popular youtubers on explaining this stuff in plain english.
About audifoolery: new speaker cables should "ripen" slowly. So, before using cables, I let them sit in my cool basement for quite some time, alongside a crate of fine Belgian Trappist beer. Once the beer has aged to perfection, the cables are ready for use. (Obviously, tasting the beer regularly is the key to success)
I was very fortunate to own the monster G22000 'receiver' back in 1978. Had it hooked up to a pair of Magnaplaner MGIIa dipole speakers, with a Sansui SR838 turntable and Stanton 681EEE cartridge. Every single person who listened to my system (from 'stereo nuts' like me, to casual listeners) were absolutely blown away by the clean, fast, powerful and 'life-like' sound. The 'high speed' design of the Sansui definitely was the major contributor to this incredible system, as I had tried other similarly powerful amps prior, but none could match the incredible Sansui...
The whole series was great. The last episode is a great summary of both the work put and attempts to analyze it why Sansui engineers built this amplifier in this particular way. It greatly shows your skills of anlysis of schemes and reverse engineering. Thank you very much for all four episodes. The series was very interesting to me. Thanks to you, I got to know this AU-X1 better and realized that it is not the equipment for me (even if I could afford it). It was not created for the music that I'm passionate about and what I listen to every day. In addition, the design, creation of the entire system based on this amplifier would absorb huge amounts of money. This is not enough for the Pioneer PL 50 L II gramophone with decent cartridge, because it is too slow, just like the same with the CD player and almost all tape recorders. In fact, tape recorders are completely off (maybe the Tandberg TDC 911 could do it, but it costs a fortune). The speakers also should be chosen wisely, only that I can not afford the Bowers & Wilkins Nautilus class equipment. It definitely is not an amplifier for me, although the lesson I received while watching the progress in the renovation was both exciting and unbelievably informative. As I see Tony, you are afraid of a shitstorm attack from so-called 'audiophiles'. I do not think there is anything you should be scared of. If they like to listen to the equipment instead of music, let them stay in their own world. Your fans (including me) first of all listen to music and the audio equipment is only to turn the material placed on the carrier into a played sound wave. If some song makes us happy, it is going to sound great even on a boombox. I am disgusted by idiots that are giving horrendous sums of money for 'playing cables' and other audiophile stuff, when they only have in the library holding three, four (maximum ten) discs sometimes, usually with terribly boring, but perfectly executed material. And they love to torture their guests with these tracks. What's better - these 'audiophiles' are usually well beyond over 50 years old and, as we all know because it is well known and practically proved, sense of hearing at this age becomes more and more dull (except for blind and visually impaired people). Thus, a handful of these loud imbeciles who, because of their age, can hear up to half of what they heard in their years of youth, tries to fool the vast majority of listeners, that their cables "play the full stage", when all the rest of the audience can hear absolutely no difference in sound between an ordinary OFC copper cable (10 cents per meter) and Fadel Art Coherenc for 1000 dollars per meter (rubbed with scorpion oil, which costs as much as the cable itself). I honestly hate this group of idiots who consider themselves to be the greatest music lovers in the world. If they live according to the saying: 'whoever forbids the rich' is their choice, but let them stop dictating to the typical person how to live, what to listen to and on what equipment. They do not have any qualifications in the direction of influence, so it is better to let them close in their own circle and bring them to the limits of ecstasy talking about obsidian stands for cables, levitating anti-vibration shelves and platinum spikes under loudspeakers. Personally, I had contact with this type of rabble on various audio forums and I can advise you to completely ignore their often offensive posts. If 'audiophile' spits venom, let it spit on itself. After some time, quite a long time unfortunately, because 'audiophilia' is usually closely related to mental illness, he will finally notice that he has achieved nothing beyond the spitting of his beard and will return in disgrace to his own den. Thank you again for all of your materials presented on RUclips. I absorb it with relentless pleasure. Waiting for the next virtual visit in your workshop. I would like to warmly greet you from Poland - arv.
14:13 In later versions of the X1 Sansui disconnected that test point on top of the drivers. So if you get an X1 made in 1980 that test point will show nothing. You will then need to check that voltage from below. 47:46 Common reaction to a well restored X1 This X1 vid series is a great contribution to the X1 knowledge pool. A thousand thanks!!!
That’s the kind of job you do for the pleasure. To perfect the art of your hobby. This level of perfection in that high-end perfect product you only can do it one way no shortcuts no cheap components you do everything or you turn around and walk away from it. This is the kind of job that you put your name on it and build your reputation. This is the kind a job in 20 years when somebody takes it apart to restore it they can tell a master worked on it Who put his heart and blood sweat and tears into bringing this unit back to life. This is the kind of job if you actually got paid for every hour that you put into it the owner of this unit would owe you their firstborn the mortgage to their house and the keys to their car.
So basically the "jump" switch is a "source direct" switch which bypasses the pre-amp and feeds the input directly to the power amp or pre-out. Maybe that's why you got such a clean 20MHz signal, you were effectively going through the input, switches and a volume pot directly to the output
I watched the four parts of the video and it was full of good and important information for those who suffer from these problems, your work is great and forward, good luck 👍
This was all pretty amazing to see, all your great work and the response of this amp. Thanks for all the videos Tony, you did a pretty stunning job here! Buddy
Several High-end manufacturers use Diamond Differential cirquit to day, krell is one of them Accuphase is another. The least expensive to day is probably Audio-GD. This amp was a ground breaking one far ahead of it's time!
Harmonic, intermodulation distortion, it’s not matter of what you actually hear, it’s what you don’t hear. Because you are actually hearing distortion canceling out frequencies, when you remove things like harmonics, component and tin vibration, cable inductance, etc., your music comes out more full, transparent, 3 dimensional and detailed. I’m not talking about detail like forward high frequencies, detail like instrument separation.
This has to be the cleanest sound on RUclips that I've heard, even allowing for compression and other parameters. The Jump switch is I would suggest now called a Direct Switch on some amps. Excellent videos Tony even for a non - electronics person like me. Thank you
Great restoration on this fantastic Sansui Tony 😎 These are a unique and special amplifier. Hope to some day listen to one of these machines and appreciate the engineering that has gone into making the performance really top notch. I have worked on and repaired/restored several Sansui's and other vintage hifi equipment as this is what I do for a living and compared to the AU919 this would be levels above that I'm sure.
Thank you for sharing your skill and workmanship on this piece . I know you love your Pioneer equipment but you have experienced something I found out when I was 10, High end Sansui equipment has a clarity you have to hear to believe..I don't have the pleasure of owning a Au-X1 but I do have a AU-X711 and I feel the same way about the phono stage...My SWMBO Hates it lol
Hi Tony, the diamond differential circuit is area you're pointing at 1h:3m:40s. it is a noise canceling circuit. If you pull up the service manual for the Sansui G-33000 and go to the 1-1 power amp section on the block diagram, this same area is circled and labeled as the pre drive diamond differential circuit. By the way, would you have made a list, over the years, of your recommended replacement manufacturer part numbers for the components you've replaced in your videos by chance? I'm just thinking that you would have thoughts on what components may have tested better than others, performance wise for audio specifically.
Listening to the RF directly is the best way to listen to a broadcast. I find that it's the most pure audio, as you don't need to have a tuner or amplifier or speakers in the audio path to distort the sound :)-)
Thank you Tony for another great video! A near perfect square wave at 1MHz from a an audio amp is mind blowing. I wonder what the slew rate is on that thing, I’d imagine close to double it’s output voltage swing per µs.
I await the day you review the replacement of relays and speaker fuses with back to back optically driven FET’s. I just got some SI8752 gate drivers, that simply require a couple of milliamperes into their drive side diode to force an attach n channel fet pair to minimum rdson. I will be trying this to dump the speaker fuses on my rebuild of a Hafler 220. Seems to me it would be possible, maybe easy, to produce an exact replacement by re-using just the mounting base of the old relay?
Hey Tony. Grat video. Could you make a list of tranzistors you replaced with the replacements you used? I will work on one of this in the future and the list will come in handy. Thank you. You sure can explain things in english for us.
16:19 : I also often wondered why manufacturers sometimes do not place the driver transistors on the output transistor heatsink. On the Bose 1800/1801 I think it is done, however, on class A Sugdens I've seen it's not, and they do get hot!
The Sansui AU-X1 was $1450.00US from 1979-81. The Sansui G 33,000 was Us.1850.00 from 1978-1979 The Sansui G8000 was $920.00 from 78-79 my baby !! Love it but my direct tone mode switch sometimes i have to wiggle it for speakers to work ehaaaa! But still 56 pound monster !
Could you recommend shops that do your kind of work in south New Jersey. Thanks for your RUclips videos. Me and my grandkids love them Alfonso from South New Jersey
37:21 : Nice info on relays. I didn't know anything about the technology of these things or that relays and contactors were different. Great stuff! Maybe you can also make a quick mention on, the once popular, now forbidden, wet mercury relays.
52:55 : I don't get it: why couldn't they leave the output of the MC amp. permanently connected to the input of the MM amp. and just use one relay to switch the phono. input between the input of the MC amp. or the MM amp.? While at it, which do you feel is better performance-wise but also cost-wise and in terms of reliability and longevity: a mechanical selector or a chain or relays? I cannot understand why relays would be chosen as they are more expensive than mechanical selectors for an equivalent performance level.
My ears do not hear up to that frequency, nor does the price of the AX 1 second hand. Think I would love one although I could build a similar one with specs as high but at a slightly less cost, at least it would be my design and of high quality and slightly cheaper then a used one of these.
36:51 : This lot must surely cost the equivalent of good amp to have them replaced. I used to think electrolytics are cheap parts but it's easy to forget the darn things are all over the place.
It should be added that it’s not just the amplifier (circuitry) that can add distortion; the speaker wires, and the speaker(s) themselves will add some finite amount of distortion. Note that I’m not considering pure resistive losses (attenuation) here; you can change the vertical gain on the scope inputs to compensate for voltage drop in the speaker cables/connectors. I’m talking about the parasitic capacitance and inductance in/on the signal path; these change the phase of the signal’s frequency components. Finally, the air itself can contribute, and don’t get me started on the frequency response of the listener’s ears! 🙃 Just get yourself a nice amp, and enjoy the music. ‘Nuff said. 😋
Believe it or not, it came from the RUclips audio library. They are getting a bit better, but I still miss being able to play the classics on these videos!
Very nice series, Tony! Thanks! Since all of the copywrite crap, I don't buy music anymore and I very rarely even listen to the radio. I hope they all go out of business.
Yeah, it is pretty sad. But greedy companies only care about money. So as long as people keep giving them money and rolling over like a puppy dog, things will just get worse.
And I feel betrayed. I am 58 and have never bought pirated music or anything in my life. If I want to read a book, I buy the book. And now someone repairing an amp or stereo can't even play a song or some riffs with their guitar without worrying about being sued?! Things are getting out of hand and just plain ridiculous.
Robert Calk Jr. you said it, if you want to hear the song, buy the song. Don’t know what you do for a living, but I’m confident you’d take offense to being asked to do it for free.
@@ronaldsantosjapan It's quite common behavior for Martin Logans, Quads etc, you can look up Sound-Lab A-1 on Stereophile and check the impedance chart for an example.
I watched this entire series from start to finish, what a beautiful amp and you did a great job on it. You often exceed some very popular youtubers on explaining this stuff in plain english.
About audifoolery: new speaker cables should "ripen" slowly. So, before using cables, I let them sit in my cool basement for quite some time, alongside a crate of fine Belgian Trappist beer. Once the beer has aged to perfection, the cables are ready for use. (Obviously, tasting the beer regularly is the key to success)
I was very fortunate to own the monster G22000 'receiver' back in 1978. Had it hooked up to a pair of Magnaplaner MGIIa dipole speakers, with a Sansui SR838 turntable and Stanton 681EEE cartridge. Every single person who listened to my system (from 'stereo nuts' like me, to casual listeners) were absolutely blown away by the clean, fast, powerful and 'life-like' sound. The 'high speed' design of the Sansui definitely was the major contributor to this incredible system, as I had tried other similarly powerful amps prior, but none could match the incredible Sansui...
The whole series was great. The last episode is a great summary of both the work put and attempts to analyze it why Sansui engineers built this amplifier in this particular way. It greatly shows your skills of anlysis of schemes and reverse engineering. Thank you very much for all four episodes.
The series was very interesting to me. Thanks to you, I got to know this AU-X1 better and realized that it is not the equipment for me (even if I could afford it). It was not created for the music that I'm passionate about and what I listen to every day. In addition, the design, creation of the entire system based on this amplifier would absorb huge amounts of money. This is not enough for the Pioneer PL 50 L II gramophone with decent cartridge, because it is too slow, just like the same with the CD player and almost all tape recorders. In fact, tape recorders are completely off (maybe the Tandberg TDC 911 could do it, but it costs a fortune). The speakers also should be chosen wisely, only that I can not afford the Bowers & Wilkins Nautilus class equipment. It definitely is not an amplifier for me, although the lesson I received while watching the progress in the renovation was both exciting and unbelievably informative.
As I see Tony, you are afraid of a shitstorm attack from so-called 'audiophiles'. I do not think there is anything you should be scared of. If they like to listen to the equipment instead of music, let them stay in their own world. Your fans (including me) first of all listen to music and the audio equipment is only to turn the material placed on the carrier into a played sound wave. If some song makes us happy, it is going to sound great even on a boombox. I am disgusted by idiots that are giving horrendous sums of money for 'playing cables' and other audiophile stuff, when they only have in the library holding three, four (maximum ten) discs sometimes, usually with terribly boring, but perfectly executed material. And they love to torture their guests with these tracks. What's better - these 'audiophiles' are usually well beyond over 50 years old and, as we all know because it is well known and practically proved, sense of hearing at this age becomes more and more dull (except for blind and visually impaired people). Thus, a handful of these loud imbeciles who, because of their age, can hear up to half of what they heard in their years of youth, tries to fool the vast majority of listeners, that their cables "play the full stage", when all the rest of the audience can hear absolutely no difference in sound between an ordinary OFC copper cable (10 cents per meter) and Fadel Art Coherenc for 1000 dollars per meter (rubbed with scorpion oil, which costs as much as the cable itself). I honestly hate this group of idiots who consider themselves to be the greatest music lovers in the world. If they live according to the saying: 'whoever forbids the rich' is their choice, but let them stop dictating to the typical person how to live, what to listen to and on what equipment. They do not have any qualifications in the direction of influence, so it is better to let them close in their own circle and bring them to the limits of ecstasy talking about obsidian stands for cables, levitating anti-vibration shelves and platinum spikes under loudspeakers.
Personally, I had contact with this type of rabble on various audio forums and I can advise you to completely ignore their often offensive posts. If 'audiophile' spits venom, let it spit on itself. After some time, quite a long time unfortunately, because 'audiophilia' is usually closely related to mental illness, he will finally notice that he has achieved nothing beyond the spitting of his beard and will return in disgrace to his own den.
Thank you again for all of your materials presented on RUclips. I absorb it with relentless pleasure. Waiting for the next virtual visit in your workshop. I would like to warmly greet you from Poland - arv.
14:13 In later versions of the X1 Sansui disconnected that test point on top of the drivers. So if you get an X1 made in 1980 that test point will show nothing. You will then need to check that voltage from below.
47:46 Common reaction to a well restored X1
This X1 vid series is a great contribution to the X1 knowledge pool. A thousand thanks!!!
That’s the kind of job you do for the pleasure. To perfect the art of your hobby. This level of perfection in that high-end perfect product you only can do it one way no shortcuts no cheap components you do everything or you turn around and walk away from it.
This is the kind of job that you put your name on it and build your reputation. This is the kind a job in 20 years when somebody takes it apart to restore it they can tell a master worked on it Who put his heart and blood sweat and tears into bringing this unit back to life. This is the kind of job if you actually got paid for every hour that you put into it the owner of this unit would owe you their firstborn the mortgage to their house and the keys to their car.
Thank you so much for this series on the AU-X1! I have one that I have owned since new and am interested in keeping it in good operation.
Fascinating series Tony! Thank you!
So basically the "jump" switch is a "source direct" switch which bypasses the pre-amp and feeds the input directly to the power amp or pre-out. Maybe that's why you got such a clean 20MHz signal, you were effectively going through the input, switches and a volume pot directly to the output
correct
I watched the four parts of the video and it was full of good and important information for those who suffer from these problems, your work is great and forward, good luck 👍
This was all pretty amazing to see, all your great work and the response of this amp. Thanks for all the videos Tony, you did a pretty stunning job here! Buddy
Several High-end manufacturers use Diamond Differential cirquit to day, krell is one of them Accuphase is another. The least expensive to day is probably Audio-GD. This amp was a ground breaking one far ahead of it's time!
Blow me down ... I could hear the incredible sound even trough crappy RUclips audio ... truly incredible ...
Harmonic, intermodulation distortion, it’s not matter of what you actually hear, it’s what you don’t hear. Because you are actually hearing distortion canceling out frequencies, when you remove things like harmonics, component and tin vibration, cable inductance, etc., your music comes out more full, transparent, 3 dimensional and detailed. I’m not talking about detail like forward high frequencies, detail like instrument separation.
Bring on the fllack😃
This has to be the cleanest sound on RUclips that I've heard, even allowing for compression and other parameters. The Jump switch is I would suggest now called a Direct Switch on some amps. Excellent videos Tony even for a non - electronics person like me. Thank you
Sansui wasn't playing games, only extreme frequency ranges. Wow! I hope my skill set reaches this level one day.
Great restoration on this fantastic Sansui Tony 😎 These are a unique and special amplifier. Hope to some day listen to one of these machines and appreciate the engineering that has gone into making the performance really top notch. I have worked on and repaired/restored several Sansui's and other vintage hifi equipment as this is what I do for a living and compared to the AU919 this would be levels above that I'm sure.
Once again Tony, great job on this Sansui.
Thank you for sharing your skill and workmanship on this piece . I know you love your Pioneer equipment but you have experienced something I found out when I was 10, High end Sansui equipment has a clarity you have to hear to believe..I don't have the pleasure of owning a Au-X1 but I do have a AU-X711 and I feel the same way about the phono stage...My SWMBO Hates it lol
Tony you make the best restoration videos. I listen to them all day while working at my computer.
Thank you...really enjoy and appreciate your channel. God Bless
Hi Tony, the diamond differential circuit is area you're pointing at 1h:3m:40s. it is a noise canceling circuit. If you pull up the service manual for the Sansui G-33000 and go to the 1-1 power amp section on the block diagram, this same area is circled and labeled as the pre drive diamond differential circuit.
By the way, would you have made a list, over the years, of your recommended replacement manufacturer part numbers for the components you've replaced in your videos by chance? I'm just thinking that you would have thoughts on what components may have tested better than others, performance wise for audio specifically.
Loved the experiment. And fantastic frequency response. I often listen to music at above 1MHz that's how good my ears are :-)
Listening to the RF directly is the best way to listen to a broadcast. I find that it's the most pure audio, as you don't need to have a tuner or amplifier or speakers in the audio path to distort the sound :)-)
Thank you Tony for another great video! A near perfect square wave at 1MHz from a an audio amp is mind blowing. I wonder what the slew rate is on that thing, I’d imagine close to double it’s output voltage swing per µs.
Simply amazing. Thank you.
Fantastic Four videos!. This was so informative! keep it up!
I await the day you review the replacement of relays and speaker fuses with back to back optically driven FET’s.
I just got some SI8752 gate drivers, that simply require a couple of milliamperes into their drive side diode to force an attach n channel fet pair to minimum rdson. I will be trying this to dump the speaker fuses on my rebuild of a Hafler 220.
Seems to me it would be possible, maybe easy, to produce an exact replacement by re-using just the mounting base of the old relay?
Hey Tony. Grat video. Could you make a list of tranzistors you replaced with the replacements you used? I will work on one of this in the future and the list will come in handy. Thank you. You sure can explain things in english for us.
Do you remember which piano record was the recording from? To me it sounded a bit warbly - which could be the record player or my ears.
16:19 : I also often wondered why manufacturers sometimes do not place the driver transistors on the output transistor heatsink. On the Bose 1800/1801 I think it is done, however, on class A Sugdens I've seen it's not, and they do get hot!
The Sansui AU-X1 was $1450.00US from 1979-81.
The Sansui G 33,000 was Us.1850.00 from 1978-1979
The Sansui G8000 was $920.00 from 78-79 my baby !! Love it but my direct tone mode switch sometimes i have to wiggle it for speakers to work ehaaaa!
But still 56 pound monster !
i just think your keithley's hook-up cables are not massaged enough to cope with that amp's bandwidth.
I would have loved to have heard it person; nice attention to detail.
Could you recommend shops that do your kind of work in south New Jersey. Thanks for your RUclips videos. Me and my grandkids love them Alfonso from South New Jersey
37:21 : Nice info on relays. I didn't know anything about the technology of these things or that relays and contactors were different. Great stuff! Maybe you can also make a quick mention on, the once popular, now forbidden, wet mercury relays.
52:55 : I don't get it: why couldn't they leave the output of the MC amp. permanently connected to the input of the MM amp. and just use one relay to switch the phono. input between the input of the MC amp. or the MM amp.?
While at it, which do you feel is better performance-wise but also cost-wise and in terms of reliability and longevity: a mechanical selector or a chain or relays? I cannot understand why relays would be chosen as they are more expensive than mechanical selectors for an equivalent performance level.
Other relay contact stuff-alcohol on paper, crocus cloth, and pen erasers :)
Great video Tony!!
1:13:30 you can use techno music as demo or testing purposes, as techno music almost all free ...
tony!! would you take mine in and rebuild it
You can record the sound via output --> audio interface --> audacity ( pc)
Wow!!!
You would have to have a REVOX B795 Turntable to enjoy the sound of that amp.
My ears do not hear up to that frequency, nor does the price of the AX 1 second hand.
Think I would love one although I could build a similar one with specs as high but at a slightly less cost, at least it would be my design and of high quality and slightly cheaper then a used one of these.
Doesn’t the Keithley only measure the second harmonic? I would expect it to measure the third also, which the human ear finds more annoying.
2:13 : You should be able to use this at broadcast FM frequencies!
36:51 : This lot must surely cost the equivalent of good amp to have them replaced. I used to think electrolytics are cheap parts but it's easy to forget the darn things are all over the place.
It should be added that it’s not just the amplifier (circuitry) that can add distortion; the speaker wires, and the speaker(s) themselves will add some finite amount of distortion. Note that I’m not considering pure resistive losses (attenuation) here; you can change the vertical gain on the scope inputs to compensate for voltage drop in the speaker cables/connectors. I’m talking about the parasitic capacitance and inductance in/on the signal path; these change the phase of the signal’s frequency components. Finally, the air itself can contribute, and don’t get me started on the frequency response of the listener’s ears! 🙃 Just get yourself a nice amp, and enjoy the music. ‘Nuff said. 😋
dam nice!
This must be a really cool amp.
Could you provide a link to the source of that last piece of piano music?
Believe it or not, it came from the RUclips audio library. They are getting a bit better, but I still miss being able to play the classics on these videos!
Very nice series, Tony! Thanks! Since all of the copywrite crap, I don't buy music anymore and I very rarely even listen to the radio. I hope they all go out of business.
What a sad perspective.
Very sad
Yeah, it is pretty sad. But greedy companies only care about money. So as long as people keep giving them money and rolling over like a puppy dog, things will just get worse.
And I feel betrayed. I am 58 and have never bought pirated music or anything in my life. If I want to read a book, I buy the book. And now someone repairing an amp or stereo can't even play a song or some riffs with their guitar without worrying about being sued?!
Things are getting out of hand and just plain ridiculous.
Robert Calk Jr. you said it, if you want to hear the song, buy the song. Don’t know what you do for a living, but I’m confident you’d take offense to being asked to do it for free.
I wouldn't try this amp with electrostatic speakers, many of them become close to short circuit at high frequencies above the audio range.
Yikes! and interesting. I'll need to Google up some examples.
@@ronaldsantosjapan It's quite common behavior for Martin Logans, Quads etc, you can look up Sound-Lab A-1 on Stereophile and check the impedance chart for an example.
Audiofoolery is a sport in and of itself lol
And your point is???
(Later: Oh....massaging speaker cables. I think I see your point. )
Yeah this is the first time I've heard of a RCA burn in machine 😱😂😂😂
I think they all need their heads examined.
I actually saw an ad for one. $400 U.S. and it's all yours! ;)
Bargain
I would dub it "The Sanslewi" :)
Lil bro AU-919 is almost as good but cheaper and less prone to self destruction.
Ow .. “Ex 1” not a fond memory LOL ...
.