Keep my 1996 bryston 4B or get a new 4B

I have a Bryston 4B I bought new in 1996 and it still works wonderfully. I been thinking of buying a brand new Bryston 4B dose it pay to spend 8500 on one and will I gain better sound then I an currently getting. I have upgraded the rest of my system in the last 2 years from a pair of dynaudio special forty speakers a rel s510 sub a rouge rp7 preamp a pro ject tubebox ds3b phono preamp and a new cocktail audio x45 streamer along with my linn turntabel. And all new pure silver audio cabels. Would I gain anything in the sound quality by replacing my amp for a new current model or would I do better to spend the money to up grade and improve my lp12 turntabel. Thank-you Michael.