Inside a AU-919 project
- Thread starter scottrt
- Start date
Elroy
was here.
Appropriately within this thread I am proud to say that I am the very fortunate new owner of this AU-919! I am not one to use the celebrating banna, but in this case they communicate my sentiments perfectly! 
This is my Christmas present and I am looking forward to its arrival and a good listening session!
This is my Christmas present and I am looking forward to its arrival and a good listening session!
Elroy
was here.
.
Elroy
was here.
I received my refurbished Sansui AU-919 from Scott yesterday evening, placed it within my system and have been listening to it last night and this afternoon. To be succinct, my expectations (which were high) were not disappointed! I have been able to give a cursory listen to a couple of CDs, my tuner and my phono. I did find that my Denon DL-301 II moving coil cartridge is not the best match as the volume needs too much compensation. The phono did sound very good but I know a more aptly matched cartridge will be excellent. Any suggestions? The other sources sound superb! I was really taken aback at the level this amplifier performs to! I have owned some really nice gear both modern and vintage and this Sansui does not take a back seat to anything. The AU-919 was originally designed to be very accurate and uncolored when new and was a ground breaking integrated amplifier in that regard at that time. Well Scott's comprehensive refurbishment has not only restored those cutting edge attributes but indeed has made a marked improvement! The newer higher performing output transistors along with the new high-end parts used throughout the restoration all have served to yield a performance noticeably better than stock WITHOUT A DOUBT! I have owned a Au-919 in the past and there is BIG difference- of course it was completely stock and 30 years old.
I played a CD using the unique "Jump" switch where it removes the flat amp from the signal path creating a more direct and "uninfluenced" signal and this thing was smack dab SPOT ON- perfect! Perfectly defined bass strokes on the bass guitar- tight and strong with no flab or muffle, the piano strikes and cymbal strikes were completely intact with no decay, distortion or sizzle. The bottom line is the high slew rate and fast rise time make a REAL and audible difference and I would summarize the AU-919 as performing to the highest degree of uncolored accuracy yet in no way would I consider it as sounding bright, forward or fatiguing. They simply got it OH so right! This is not a typical "warm" sounding amp of the 70's and in my estimation will hold its own with any high end amplifier costing thousands today. Needless to say I am tickled pink with it and cannot recommend Scott highly enough! If you can get your hands on one his comprehensively restored and IMPROVED Sansui amps by all means jump on it! :thmbsp: Thanks Scott!
I played a CD using the unique "Jump" switch where it removes the flat amp from the signal path creating a more direct and "uninfluenced" signal and this thing was smack dab SPOT ON- perfect! Perfectly defined bass strokes on the bass guitar- tight and strong with no flab or muffle, the piano strikes and cymbal strikes were completely intact with no decay, distortion or sizzle. The bottom line is the high slew rate and fast rise time make a REAL and audible difference and I would summarize the AU-919 as performing to the highest degree of uncolored accuracy yet in no way would I consider it as sounding bright, forward or fatiguing. They simply got it OH so right! This is not a typical "warm" sounding amp of the 70's and in my estimation will hold its own with any high end amplifier costing thousands today. Needless to say I am tickled pink with it and cannot recommend Scott highly enough! If you can get your hands on one his comprehensively restored and IMPROVED Sansui amps by all means jump on it! :thmbsp: Thanks Scott!
scottrt
Well-Known Member
AU-919 restoration
Hey Elroy:
Thanks for the kind words, and thanks to the many Guru contributors on this forum. Without their help I wouldn't have had the courage to undertake this complex a project, or the knowledge to get it 'right'.
I have to specially thank EchoWars for his contributions.
The MC phono input is reported to have a very low impedance. I've read both 10 ohms and 33 ohms. I never measured it. This is really low. Too low for many modern MC carts. Your DL-301 mk2 recommends 'greater than 100 ohms' impedance. THis is why the gain and dynamic seem lacking.
How high do you have to turn the volume to get a satisfying output level? More than 1:00? If not, I wouldn't be bothered by it. Also, the only part of the amp I didn't burn it for over 48 hours was the phono stage. Less than two hours on all those new caps and transistors. I'm sure the Silmic II's will sound much nicer after /20/30/40/ hours on them. Of course, they're not going to sound any louder. Maybe somebody can chime in on Elna Silmic burn-in times.
There are some very knowledgeable members at the vinyl asylum of Audio Asylum when it comes to MC carts and loading preferences. Off the top, I'm pretty sure that Denon's DL-103 line likes to live at 40 ohms, and perhaps does fine at 10.
Of course, there is always the option of a stand-alone phono amp, or in your case, you might seriously consider a simple step-up transformer in a case with jacks. This would go between your TT and MM phono input. You would be able to set it up for plenty of gain and whatever loading you desire. Attached is a pic of one I made for myself with Cinemag transformers and variable loading resistors. I wouldn't be without it.
Scott T.
Hey Elroy:
Thanks for the kind words, and thanks to the many Guru contributors on this forum. Without their help I wouldn't have had the courage to undertake this complex a project, or the knowledge to get it 'right'.
I have to specially thank EchoWars for his contributions.
The MC phono input is reported to have a very low impedance. I've read both 10 ohms and 33 ohms. I never measured it. This is really low. Too low for many modern MC carts. Your DL-301 mk2 recommends 'greater than 100 ohms' impedance. THis is why the gain and dynamic seem lacking.
How high do you have to turn the volume to get a satisfying output level? More than 1:00? If not, I wouldn't be bothered by it. Also, the only part of the amp I didn't burn it for over 48 hours was the phono stage. Less than two hours on all those new caps and transistors. I'm sure the Silmic II's will sound much nicer after /20/30/40/ hours on them. Of course, they're not going to sound any louder. Maybe somebody can chime in on Elna Silmic burn-in times.
There are some very knowledgeable members at the vinyl asylum of Audio Asylum when it comes to MC carts and loading preferences. Off the top, I'm pretty sure that Denon's DL-103 line likes to live at 40 ohms, and perhaps does fine at 10.
Of course, there is always the option of a stand-alone phono amp, or in your case, you might seriously consider a simple step-up transformer in a case with jacks. This would go between your TT and MM phono input. You would be able to set it up for plenty of gain and whatever loading you desire. Attached is a pic of one I made for myself with Cinemag transformers and variable loading resistors. I wouldn't be without it.
Scott T.
Attachments
Elroy
was here.
It seems I need to have the volume at 11:00 for normal listening and 12:00 for "spirited" listening. Not really bad just not ideal. It really does sound good and that's something I hadn't factored was the fact that the MC pre-pre board probably just needs some burning in. Even so I will keep my ear to the ground for a more ideal MC cartridge worthy of this excellent phono section.
Right now I am enjoying some Guess Who- "No suger tonight in my coffee...." Just spinning a few good records tonight and enjoying the music with a good cigar as the snow blankets the ground outside
Cheers!
Right now I am enjoying some Guess Who- "No suger tonight in my coffee...." Just spinning a few good records tonight and enjoying the music with a good cigar as the snow blankets the ground outside
Cheers!
scottrt
Well-Known Member
Those volume setting are normal for any Sansui amp or any amp I've owned. 9:00 with CD = 11:00 set to phono.
As a vinyl fan, I would recommend a medium output (0.7mv - 1.0 mv) MC cart. A Benz Ace medium output or Wood Medium (both 0.8mv) would be awesome sounding, and drive hard enough thru the mc input that it would alot closer to the CD player on the volume knob vs spl level.
Keep your eye on Audiogon for a good deal on a lightly used one and save 40 to 50 percent of new. They do show up on occasion, but are sold within a few hours usually.
Now...back to the music.....
Scott T.
As a vinyl fan, I would recommend a medium output (0.7mv - 1.0 mv) MC cart. A Benz Ace medium output or Wood Medium (both 0.8mv) would be awesome sounding, and drive hard enough thru the mc input that it would alot closer to the CD player on the volume knob vs spl level.
Keep your eye on Audiogon for a good deal on a lightly used one and save 40 to 50 percent of new. They do show up on occasion, but are sold within a few hours usually.
Now...back to the music.....
Scott T.
ghamilton
Super Member
My rebuilt 919 has the elna selmic II caps throughout. Also a few panasonic fc caps. Give it a couple of weeks for break-in.
As for a phono cartridge I have the Grado low output ($1200) statement/reference. This is next to the statement,...which is there most expensive ($3000). I had to change the two resistors on the MC board to 47.5 kohm resistors to get the correct balance. Now for my recomendation.
You would be very shocked at the performance of the Shure M97xE with the newest Jico SAS stylus for that cartridge. No MC stage needed.
My setup:
Sansui AU-919
Sota Sapphire
Sumiko FT-3 arm
Vandersteen one's
As for a phono cartridge I have the Grado low output ($1200) statement/reference. This is next to the statement,...which is there most expensive ($3000). I had to change the two resistors on the MC board to 47.5 kohm resistors to get the correct balance. Now for my recomendation.
You would be very shocked at the performance of the Shure M97xE with the newest Jico SAS stylus for that cartridge. No MC stage needed.
My setup:
Sansui AU-919
Sota Sapphire
Sumiko FT-3 arm
Vandersteen one's
usedto
Lunatic Member
I am using an AU717 and AU719, both with the same results.
bebopdeluxe
Well-Known Member
Excellent choices on the cartridges...I have used both with the AU-919 that Glenn (EchoWars) refurbished (although the ACE was a high-output)...I currently run with a Wood M2 and it is a wonderful match.
Enjoy!
xoaphexox
Supernatural Anesthetist
I see you got the 'F' variant of the 992 and 1845. Did you by chance test these for gain to see if they were close to the stock beta of 500? The data sheet shows a 300-600 range.
I have hordes of the 'E' variant which on average are a bit more gain (400-800) and I am wondering if it would be detrimental to use them if they are closer to 800 than 500.
Thanks for any input.
Update, while the circuit page says E,U - the schematic says F,E - so I may be OK after all...
I have hordes of the 'E' variant which on average are a bit more gain (400-800) and I am wondering if it would be detrimental to use them if they are closer to 800 than 500.
Thanks for any input.
Update, while the circuit page says E,U - the schematic says F,E - so I may be OK after all...
marsellas3
New Member
Hi! Could anyone help to locate the issue?
Just finished total restoration and recapp of my 919 and noticed a slight buzz (50 hz hum) from preamp transformer which coming through to the speakers. The buzz in the speaker does not depend on the volume level. All the screws are tightened properly and the ground is good.
The Oval caps were tested and seems they are good (the only caps which were not replaced). Initially this amp was bought by me with the blown preamp stage (the amp had been fallen down and damaged!!). Maybe that preamp traisformer was overheated and damaged accordingly? Or should I have to change the ovals first? As for the sound - no comments, Great. The only issue with the slight buzz. I'm sure that this top amp definetely has to be dead silent. Do anyone have the idea?
Just finished total restoration and recapp of my 919 and noticed a slight buzz (50 hz hum) from preamp transformer which coming through to the speakers. The buzz in the speaker does not depend on the volume level. All the screws are tightened properly and the ground is good.
The Oval caps were tested and seems they are good (the only caps which were not replaced). Initially this amp was bought by me with the blown preamp stage (the amp had been fallen down and damaged!!). Maybe that preamp traisformer was overheated and damaged accordingly? Or should I have to change the ovals first? As for the sound - no comments, Great. The only issue with the slight buzz. I'm sure that this top amp definetely has to be dead silent. Do anyone have the idea?
