Tuberolling the REF5se...

just dropped in a NOS 60's Tung Sol black plate 6550 ... wow relavator moment for sure....
Sourced from Andy at Vintage
the bottle shape does contact the damper on adjacent tube..

immediate thoughts
better depth of image
sharper attack midbass up thru midrange
smoother than the stock tube

listening to Leonard - You Want it Darker, Getz- Gilberto, and Wailing Jennys Firecracker

Mixed thoughts from others on the very expensive and sometimes counterfeit-DR you have them ? Where did you source ? Changes in sound ?

Yes , did buy aprox 8 years ago , from a retailer in Canada , for my REF 3 and for my CD7 . They last 2 times the lifetime of the regular tubes .
The sound , more dynamics in general .

+1 for Andy at Vintage..

Tube rolling fun, and the gospel, make old[er] classics new and 'born again' ! :-D