Jump to content

Sansui Alpha Series Amplifier Reviews


Recommended Posts

  • Replies 336
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

I probably should be holding off on creating this thread but I've been so slack lately that I haven't had anything to post about and the lack of anything to write has me breaking out in hives so I tho

I'm not sure if I should be posting this here or start a new thread for the Wilson Benesh Discovery stand mounts but since I've already got the Sansui thread I figure I might as well continue. I

I was listening to the Sansui 907 NRA on my ML2 Limiteds a while ago (quite a while ago I think, some time last year actually) and I was really enjoying the combo (check out my "Addicts Guide" thread

4 hours ago, Cafad said:

Thanks Huxxy, I managed to track down the gentleman who made that post that you quoted above and PM'ed him over on Audiokarma.  He does not know what the fault was as such but is of the opinion that if a particular 607 NRA is faulty then it simply will not work (rather than it doing anything drastic like emitting smoke or destroying speakers, which was what I was afraid of).  So if a particular 607 NRA works then it is either a unit without the fault or one that was fixed by Sansui for free back when it was current.

 

Also, on a related but different note, I think I should put a time limit on this offer of a 907 that I made for info regarding the Alpha 907 EXTRA.  I'll leave the offer open until the end of August 2018 (midnight, GMT +10 hours, August 31st for those who need more specific info), almost 2 months left for anyone who feels they might be able to score themselves a 907.

 

 

Hey cafad, sorry for not linking that forum. I wasnt trying to be obtuse, just only so much time and cut and paste on a mobile phone is painfull :)

 

I cant find the other article/forum i read somewhere in the tubes.... but recall it was like ~300 of the I were made before the problem was spotted.

And, sadly, I thought the trouble was rather self-destructive??

 

Link to post
Share on other sites

You're right mate, I found the source pretty quick.

I don't know just how self destructive this fault was but word is that it is a fault that doesn't hide for very long.  So any 607's that have been used for any length of time should be ones that are fault free.

 

Edit:

I dropped off the Extra and the L Extra to Andy for some technical TLC.  It seems the L Extra had some non-genuine parts fitted so I'm hoping this solves the whole "doesn't sound much like its brothers" situation that I thought I had found.  No news on the Extra yet.

Edited by Cafad
  • Like 1
Link to post
Share on other sites


  • 4 weeks later...

I received an update email from Andy yesterday, the L Extra had a non-genuine relay fitted on the speaker board (now replaced with a genuine one), it has had some work done on the power amp select switch for unknown reasons and it has a rather nasty crack in the preamp PCB.  The PCB crack had been repaired but not well enough for Andy so he has re-repaired it.  

I had no idea it was that unwell. 

 

Still no news on the Extra.

  • Like 2
Link to post
Share on other sites

It seems all the Extra needed was a few switches cleaned.  Both the Extras are now back home and sounding much healthier than they were previously.

IMG_0759.thumb.JPG.3d72a98e2c44e9b54ed8168745d94888.JPG

 

The L Extra no longer has a recessed sound stage and the mids aren't as soft as they were although the bass is still a bit on the soft side.  The Extra sounds very much like the 907i but a little cleaner in the top end and maybe a slightly lower noise floor.  So yes, the Sansui that shouldn't exist sounds very Sansui-like.

Also, and this is completely irrelevant to the sound side of things, the Extra seems to have been polished in recent memory as it isn't just a beautiful black face plate but a shiny and clean beautiful black face plate.  There are a few dings on the left top and left front edge but it's still a pretty face. Pictures just don't do it justice.

 

No progress on finding any info on it guys?  Time is marching on and my reward offer expires at the end of the month.

Edited by Cafad
  • Like 3
Link to post
Share on other sites
57 minutes ago, Cafad said:

No progress on finding any info on it guys?  Time is marching on and my reward offer expires at the end of the month.

 

It's taking me longer than I thought to doctor the necessary info and photos, host it somewhere on the web, and wait for the google sniffers to catalogue it.

 

Once this happens... huzzah!

  • Like 2
  • Haha 1
Link to post
Share on other sites
On 06/08/2018 at 10:19 AM, pete_mac said:

 

It's taking me longer than I thought to doctor the necessary info and photos, host it somewhere on the web, and wait for the google sniffers to catalogue it.

 

Once this happens... huzzah!

That's a very cunning plan you have there Pete.  You've obviously put some serious thought into this.

  • Like 1
Link to post
Share on other sites


4 minutes ago, Cafad said:

That's a very cunning plan you have there Pete.  You've obviously put some serious thought into this.

 

Desperate times call for desperate measures!!

  • Like 1
Link to post
Share on other sites
  • 2 weeks later...

Got word back from Andy today, he found nothing wrong with the MR (although he did clean all the switches and pots while he was looking, so that's a good thing) so I am forced to conclude that it is actually meant to sound a little more on the "harder and more detailed" side of the street.  Closer to the sound of the new Sony TA-A1ES (although not so close as to make it difficult to listen to, like the Sony was, I'm still disappointed about that) than the other Sansuis.

 

Now all I need is a switch clean for the 907i and a power button check for the KX and they'll be ready to move on to their next owners.  Oh, and I have to wait for midnight on the 31st to pass us by, just in case.

  • Like 2
Link to post
Share on other sites

I made a few changes to my listening room over the last week.  I decided to try moving my speakers about in search of that mythical position where they 'disappear' and release all that magical sound stage energy as they slide sideways into a parallel dimension that is constructed purely of sonic bliss.

 

Or at least this was what I had been lead to believe would happen.  The reality was far less satisfying.  I spent a couple of hours moving speakers and stands left and right and back and forward and finding no difference that I considered to be worthwhile I even tried the position recommended by an on line calculator.  The on line calculator says that they should be about 4 inches closer together than they are in the pic below.

IMG_0776.thumb.JPG.801354c6d47837cf160d5f0ac7d796e5.JPG

 

This puts them far enough into the room to be a real annoyance.  Were I to find that this position opened a doorway to some sort of sonic nirvana then I could live with it, but if not then they would be going straight back to their previous corner possies.  After moving them about I decided to test run my Densen gear as I had put it up for sale and received a few PMs asking some questions about it.  I came to the conclusion that the speaker position above did indeed help the vocal sound stage but it only offered minimal improvements on instruments and then only on some songs.  I reached a similar conclusion with the Technical Brain, just before I put the Densen gear into use.

 

Then I decided that I might just put a Sansui back into action.  Why not?  It was, after all, a rainy Sunday and it didn't look like the rain was going to let up any time soon.  So, out comes the 907 NRA.  

 

I'm only going to give the new speaker position a little of the credit here, as I believe that 90% of the improvement I'm hearing over the NRA's previous performances is due to the use of the balanced outputs on the cd917 and the balanced inputs (of course) on the NRA.  And the improvement is not a small one.

The NRA rocks far harder with an extra 6db of gain, so very, very, very much harder.:)  

 

Only one thing could improve this afternoon, and I have several of those 'things' in the fridge, so this afternoon is looking good.

 

Sansui Forever!

  • Like 2
Link to post
Share on other sites


  • 1 month later...

Big news about Sansuis this last week guys.  News to me at any rate, two snippets of news actually. 

Not news to many others I imagine but bound to be news to a few so I'll address them both here.

 

I didn't realize that all the Sansui Alpha series amps are bridged designs.  So both the red and black speaker terminals are "hot".  I discovered this reading a thread over on Audiokarma.  This blew my mind some as bridged designs have some traditional issues, stability being one and enhanced distortion being another and yet neither of those seem to be personality traits of the Alpha series (or at least if they are then no one is talking about them).  If any techies would like to speculate on those topics please do, I'm not electronically knowledgeable enough to attempt it myself.

 

The second stems from the first and my misunderstanding of how the Sansui Alpha Integrated power amp sections are set up.  Having looked inside many 907 Alphas by now I was aware that each and every 907 up to the MR used 8 transistors per side, but the 907NRA uses only 4.  These are the same transistors as used in the B-2302 power amp and were specially made for Sansui.  I assumed that all the other NRA models used the same transistors, but they do not.  So I'm left wondering just how similar the NRA models sound to the 907.  

 

Well, like I said, they were big news to me.  To others maybe not so much.

  • Like 2
Link to post
Share on other sites
10 minutes ago, huxmut said:

Are they bridged and floating as in BTL ?

 

That would mean they need four amplifier sections ???

 

 

I believe so.

 

Yep, and they have them.  Two sections on each board.

au-alpha907i(4).JPG.fe31bbd85918be1c2588f70d69c45800.JPG

This is a pic from the 907i info sheet.  Draw a line down the middle and tell me if it looks like two separate sections.

 

Link to post
Share on other sites


Hopefully @skippy124   or @PeteMac  can help out with a little tech-head info :)

 

Seems this is a part of the diamond differential circuit design

 

https://audio-database.com/SANSUI/amp/au-alpha907dr-e.html

 

Quote

Furthermore, by + and - side having 4 amplifier stream compositions which had exclusive amplifier, respectively, a forcible sound is gained by the low distortion for the push pull scheme which + and - side drives from bothways on the same requirements.

 

Edited by huxmut
Link to post
Share on other sites
  • 2 weeks later...

So the non L Extra remains a mystery ?

Maybe it's a prototype/pre-production run that was used for testing or something along those lines

And the "L" was added between that and the final signoff for production to comence

 

???

Link to post
Share on other sites
10 minutes ago, huxmut said:

A "special" for an executive perhaps ?

Where's that petemac page with the info ?

:)

 

Maybe, or a unit built for advertising and promotional purposes.  If it was built to look pretty then that could explain the colourful heat sinks.

  • Like 1
Link to post
Share on other sites
3 minutes ago, Cafad said:

Maybe, or a unit built for advertising and promotional purposes.  If it was built to look pretty then that could explain the colourful heat sinks.

Did you see the write up on AK from member smurfer77?

 

 

My ex-sansui contact says that they and their immediate contacts don't recall a 907 Extra and was very interesting for them to see Cafad actually has one. It doesn't appear to be documented on japanese sites.

The "L", in the case of x07 series, may likely have indicated LAPT according to my source.

And while he or his own contacts couldn't (yet) dig up info on the 907 Extra, they thought it likely to be a small production run (maybe 1000) due to LAPT transistor production not meeting the schedule (with the idea being to get some 907 Extras out and then abandon that when the LAPT production caught up and move over to the 907L Extra).

Well, this theory will soon be either debunked or partly validated when Cafad's amp has a service and the output transistors are inspected.

The intriguing part is that Cafad's amp doesn't have a serial number and if it never had one it is still possible that it was a prototype (however, my contact speculates that is less likely than a small production run, although it's still possible an employee took one home). Cafad's amp also has some other interesting features, such as copper looking, instead of usual black heat sinks. This all makes it look a bit 'prototype', but I do note I have now seen several alphas on japanese auction sites with copper looking (to varying degree) heatsinks; it appears that certain black treatment they used (perhaps not on all alphas) can actually come off when the heat sinks run too hot.

  • Like 1
Link to post
Share on other sites

Yep, Smurfer and I have been chatting via PM.  I hope his contacts can find out more.

I'm a bit disappointed (if that is the word) that the 907 EXTRA didn't require much work when it went to Andy's as all it needed was a switch clean so there was no need to disassemble it.  Which means that we don't know the identity of the transistors. 

 

I'll probably have to pull it apart myself in order to identify them. 

  • Like 2
Link to post
Share on other sites
3 hours ago, Cafad said:

Yep, Smurfer and I have been chatting via PM.  I hope his contacts can find out more.

I'm a bit disappointed (if that is the word) that the 907 EXTRA didn't require much work when it went to Andy's as all it needed was a switch clean so there was no need to disassemble it.  Which means that we don't know the identity of the transistors. 

 

I'll probably have to pull it apart myself in order to identify them. 

 

You might be able to get a good look at them by removing the bottom panel of the amp. :)

  • Like 1
Link to post
Share on other sites
20 minutes ago, huxmut said:

"Disappointed" is not the word :)

True.

 

Hmmmm, if I unscrew that copper clamping plate will I be able to put it back on without needing to re-apply any heat transfer compound?  

IMG_0803.thumb.JPG.068f57bdfc8300b45c3c6bbf573d8f4a.JPGIMG_0804.thumb.JPG.bdecedb428ce2897df201c43e2ca42be.JPGIMG_0805.thumb.JPG.12ae1ef5519e3ef585269746be156122.JPG

 

Because if so then I really shouldn't try until I'm properly prepared and equipped.

 

(Love all that orange metal, doesn't it look good?)

 

 

Edited by Cafad
  • Like 1
Link to post
Share on other sites

Be super careful Cafad.

If that is copper screws into copper heatsink then those screws might be close to impossible to remove without destroying them.

Fingers crossed they have a lubricant on them and will be fairly easy to loosen off.

Link to post
Share on other sites

Just thinking and posting without much consideration....

Are there any physical difference or electrical characteristics that could be checked and or measured to show a difference in those transistors ?

Edited by huxmut
Link to post
Share on other sites
1 hour ago, huxmut said:

Be super careful Cafad.

If that is copper screws into copper heatsink then those screws might be close to impossible to remove without destroying them.

Fingers crossed they have a lubricant on them and will be fairly easy to loosen off.

I think I'll be holding off until I get some advice from an expert.  I'm not a fan of trusting to luck.

  • Like 1
Link to post
Share on other sites

I wonder, what is the next Sansui for this thread 🤡

 

hehehe, I'm excited for you @Cafad.

Snapper()'s comments aren't the only positive ones I've read on the www for the dark horse.

 

And to think a DAC and a Remote ....

Link to post
Share on other sites

Me too mate, me too.

 

Technically I don't have the remote yet, I have a remote but I'm not sure it will work.  However it is a big internet out there so there is always hope of finding an original remote.  If not, a Harmony may just find its way onto my shopping list.

  • Like 1
Link to post
Share on other sites

I have a spare (Minty Condition) Logitech 650 that told me it likes Sansui's

Yours if you want ? Let me know.

Hahaha, just went and dug it up. Still has the plastic protector strips on it :)

 

Edited by huxmut
  • Like 1
Link to post
Share on other sites
49 minutes ago, huxmut said:

More hints required ?

Cafad hopes it is Delightfully Good ;)

 

I always thought those initials stood for Dangerous Goods.

  • Like 1
Link to post
Share on other sites

Yep, a definite rarity.  A 120/220/240 volt Sansui with both a built in DAC and a remote volume control.  I'm planning on doing a little DAC A/B-ing this evening, just for the heck of it.

 

 

The current remote that I have for the 917XR cd player doesn't work with it, but there seems to be an original remote on Yahoo so we'll see what we can see in the days to come.

Edited by Cafad
  • Like 1
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By Zoobz
      Item Condition: Good for age Shipping Options: Pickup available and you can audition. Suburb or Town: Coburg North State: Victoria Payment Method: Cash on Pick up Reason for selling: Paradigm Monitors Infinity Alpha Series 5.1 home theatre speakers.
      Made in Denmark. 
       
      2 x Front Towers, Alpha 40 3 way
      2 x Bookshelf Rear, Alpha 20 2-way
      1 x Center, Alpha Center, 2-way (tweeter damaged, still acoustically good)
      1 x Suberwoofer HPS250 12" down firing
       
      I brought these used about 2 years ago and besides the tweeter on centre (something to remember my 2yo by)...there is no additional damage. There some signs of cosmetic minor wear you can expect
       - few scuffs
       - minor delamination on a few corners
       ...but overall they are in pretty good nick.
       
      No grilles...that's how they when I purchased them. There some small screw holes at the base of the bookshelfs, when they were wall mounted. 
      Selling due to upgrading to Paradigm Monitor 5.1 set up. 
       
      Happy to send anyone more pics, if anyone is interested. 
      Can audition if required. Pick up only, from Coburg North.
       
      Price is for the full 5.1 Set-up. 
       
      Photos:











    • By Igotmearecord
      Item Condition: used - near mint condition for age Shipping Options: Pickup available and you can audition.,Shipping is available at agreed cost. Suburb or Town: Tura Beach State: New South Wales Payment Method: Paypal F&F, EFT Reason for selling: Not being used. Downsizing and rationalising Further information:
       A beautiful Sansui equaliser in black finish in stunning condition. It comes with original packaging, instruction manual (quite handy for this one to learn how to drive it) and rack mount handles.
       
      It is in near new condition and all functions work. The motorised sliders are smooth and all are OK. The factory presets work and the unit defaults to them after being powered down for the correct amount of time. 
      It is a multi-voltage unit and is set internally to 240v.
      Unfortunately, I don't have the original set-up microphone. I do have a Denon DM-S205 set-up microphone I can include with it but I don't know if it is 100% compatible and I haven't tested it with the equaliser. Alternatively, I have read up about a Behringer ECM8000 mic that should be compatible and is available on eBay. The original mic was an omni-directional 600ohm but nothing particularly special as far as I can determine.
       
      I think the price is fair considering the offerings currently available as checked out using HiFi Shark. 
       
      It has the original packaging and I will add extra outer layers to protect it further for shipping. Postage within Australia using parcel post will be about $80-$100 including insurance. If interested, give me your postcode and I will get a more accurate price. 
      International shipping is available at extra cost. Ask me to get a quote if interested.

      Photos:
       
      PLEASE READ
      If you are advertising multiple items, you must post one bulk price only, or post seperate ads for each item If you include any reference to pricing whatsoever in this section (excluding RRP), your ad will not be approved If you don't include photographs of the actual item being sold, your ad will not be approved








    • By lebowski
      slowly upgrading to better gear, but this is where I am at right now.
      Speaker upgrade later this year.

      I'm going to move the TV a bit lower on the wall. It's a 50" but looks small as the room is almost 6m wide x 13 metres long and 3.3 metre ceiling height ... not the easiest room for music

    • By Sansui77
      The Sansui Awesome Foursome Review 2020.
       
      List on contenders;
      Sansui AU-111 (1966) vs AU-1111 MOS Vintage (1989) vs Alpha 907 Limited (1994) vs Alpha 907 NRA (1998). Might add another contender or two in the mix. I'd love a restored AU-X1 into the mix that way we have pretty much one from each decade.
       
      Thinking of a small gtg of passionate Sansui nutters only 🥴
      It could be some time before this actually happens but stay tuned. Looking in August or September depending on the Cov19 situation.
       
      What are your thoughts or opinions on what will sound the best to you.
      What design do you prefer internally or externally with built quality
      Black, silver or gold.
      Functionality - features they offer
      Svetlana 6L6GC Power Tubes vs Mosfets vs NM-LAPT transistors. 
      Mr Kosaku Kikuchi vs Mr Ichirou Ohshima designs
       

       
       
    • By olegau
      Item Condition: Good Shipping Options: Pickup available and you can audition. Suburb or Town: Melbourne State: Victoria Payment Method: Cash on Pickup Reason for selling: Do not need Further information: 
       Good working order, was serviced recently. The power lamp was replaced with a LED.
      Photos: Advertisements without photos of the actual item will not be approved.



×
×
  • Create New...