Bryston serial codes-how do you get date?

Know I got an email fom a prspective seller but unfotuntely didn't write it down nefore the email got deleted.If amybody can help me out be apprecited.Was really looking for an 4B ST but fellow who gave me info was early in bidding on Ebay with a B60 and I think it had not only the serial code but also adate code stickermaking it a snap.I am getting impressionm that folks are spending same amount on Brystons that is 16 years old verus one that is 4 years old which any small updated to cicutry before new series seesm to not make sense just because well one if practically new the other is at the end of many amps life spans.Not sure if the ST's will last 25,35.or 50 years (certainly they are better built since 20 years when it comes to amps is end of life of the average Bear.But want to know what I am looking at if serial is given.Checked Bryston site and it wasn't much help beyond touting 20 years.
Much thanks
I have a 4B-ST, but I can't remember if the date of manufacture is part of the serial number or is a separate date code on the unit. What I do know is that Bryston was very helpful via email when I had questions. I emailed them several times asking about the age and repair history of various used Bryston amps and they always responded within 24 hours.

Send them an email - I am confident that they will answer your questions.
You will need to brush up on the pythagorean theorum, and have a slide rule to calculate the date!
I just sold a 4B THX through Audiogon last weekend. While my ad was posted a bunch of people asked about the serial number and build date so I e-mailed Bryston. They didn't give me an exact build date, but they did narrow it down to within two years.
That's weird.I thought numbers coresponded to months as well as year very accurately with few digits form the number in that years run if they had a lkarge rub (Maybe they made 1,000 units that year but I doubt it.Could be made more than 4 digitas but doubt if theyeber sold 10,00 inn one year.We'd all have them like ASdvent booksjhelf speakers)Which reminds me of a "fable (true or not) that Kloss after AR and KLH wanted a widescreen TV like saw say on Star Trek.What did he know how to do that could make money?Make speakers.And they were the Adavent speakers bests ellers in history all to fund a failed tech (remeber how awful thos Kloss Nova Beams looked in bars back in 70's.But that's another story/string).But like I said guy with B-60 had exact date on seperate sticker but he told me how it coresponded to regular serial number.Don't think that Bryston liked to repair form free 21 or 22 year old units if they didn't have to so maybe you just had some slacker on phone who didn't want to ask around.But that is strange eh what?
Look at the date code for the date of manufacture. If the date code reads 0601, that means week 01 of the year 2006.
Is that first four or last four numbers?I seem to remember more numberson the serial number sticker.
I have only ever seen 4 digits on a Bryston date code, have owned several amps and preamps from the ST series through the current version SST series.
Three digit codes(YMM): Last digit of year then month of the year. I don't think the 80s had a code so its only for the 90's. In 2000 they changed to the four digit codes.
Four Digit Codes(YYWW): Last two digits of the year followed by the week of the year. The date codes may not always be exact. Serial Number is the most accurate. Besides if the unit is stolen or tampered with its warranty may have been voided and it would say it on the serial number card. Call the 800# or email them.
I've had a multitude of Bryston amps and preamps, most have 6 digits and you can't glean a date from those number. 505395 is a recent 5B preamp and 448577 was the 4B amp. Calling is the way to find out