Thanks for checking. Now if I could just get you to check some of my other memory lapses. 
Ok cool . That's a pretty early one then.Hi @Paul054, welcome to AudioKarma Exclusively Sansui. Thanks for making your first post a serial number. Your AU-6500 was the 28th unit off assembly line 01 in November of 1973.
- Pete
AU-X701,607050349,stereo71
Curious when Sansui changed from the old logo, to the newer one, in 1987. This unit has the old logo...most pics of this amp available online show the newer one.
Thanks Pete!
It would have also been on the box it came in but that's probably long gone. Looking at pictures on the internet, it should be on the left side of the back deck under the input RCA jacks. Does it look like it's been scraped off?Ok cool . That's a pretty early one then.
Ive also recently bought an AU6600 and it has no serial number on the back plate. Would it be located anywhere else like inside the cover? I also have a 6900 I will find it and get that number to you as well
@stereo71,
Officially, the logo changed June of 87 according to a company history I saw somewhere quite a while ago. Print advertising and any products launched from June 87 onwards had the new logo. Products already in production appear to have had the logo change phased in as parts with the old logo were depleted. I imagine owners and service manuals were reprinted on a phased in basis as well, as I've seen manuals for some models with two versions, one for each logo.
I just picked up a CD-X701 CD player with an old logo, but most I see pictures of have the new logo, just as one example. The front panels are actually different, the old logo version has a stamped in rectangular recess for the badge, the new style has the badge surface mounted on two pegs that go through the panel. The screen print of the model number is positioned differently between the two versions as well.
I need to submit serials for that unit, and several other recent acquisitions here. Will do so shortly.
Have the following to add:
CA-606,233040176,Sansuiman,JDM 100V
BA-150,211010083,Sansuiman,JDM 100V
AU-555A-820062426,Sansuiman,JDM 100V
QS-1,221021203,Sansuiman,JDM 100V
@stereo71 - my 5000X is like that as well. Rather a foolish placement of the S/N on the wood case, I think. This may be due to the 5000X adding pre-out/main ins on the rear panel.
I've updated the Sansui Serial Number Database. It had not been updated since January 2009. I've compiled all the serial numbers posted in the database update thread.
The updated Sansui Serial Number list is now resides in the Digital Docs forum. You can get to it directly by clicking on this link: Sansui Serial Number Data.
The database is extremely useful to determine things like the time frame units were built and the approximate number of units built. The more serial numbers collected, the better the data.
Please post your serial numbers to the 2017 database update thread located here.
When posting serial numbers please use this format: Serial Number, Model, AK handle. Like this: AU-919,220031540,LBPete. This format lets me cut and paste a list with all the data that can be uploaded into MS Access. Otherwise I have to reformat the data into this format. The commas are very important. They tell access to skip to the next field.
Lastly, please double check your serial numbers after you post them. There are a lot of decoding errors because the serial number don't follow the correct date format or the number of digits is wrong. Most equipment is 9 digits except speakers and some other oddball stuff. The 4 and 5 digits must equal a month designation.
- Pete
Maybe I'm looking in the wrong place, or something is wrong with my laptop, but there are no UNs where I'm looking...Not to speak for Pete, but one AK username is incorporated into the database for each entry of gear they personally own, if submitted. Those serials scraped from online photos (sales or otherwise) are noted thusly in the username field. More recently Pete has added a miscellaneous notes field to add other pertinent information about units submitted for inclusion.