Great seller, fast shipping, very responsive. Nothing but a great experience.

They look a lot like JM Audio open back HP. Any relation?

Wow, monos are really hard to find these days. And it often comes with a not so nice price tag... I hope you gotta good deal, but I'm sure they are worth quite a lot! Most feedbacks are "ground breaking".

How many companies actually produced U52 tubes back them? I have done some research and in the end it seems all U52 were made by OSRAM. Was Marconi any different?

I'm putting up for sale my U52 and Sylvania 2A3, which where my go to combo on the Stratus up to a few months ago. If anyone is interested, check out my FS topics.

The Sophia's are the only fat princess I ever felt in love with. Nice pic!

Nice christimas gift ;)

You`ll find a post in this very topic where Donald says it is not optimal to use the 274B as a rectifier for the Stratus.

  Yes I did, and also the Reflektor Cryo from pcx. Even having around 20 driver tubes for the Stratus (from Tung-Sol to Amperex, Brimar, RCA, etc..), I still think the 6N1P-EV cryo sounds best. Between the Reflektor and the Voshod I have no real preference as both sound the same to me.

  As far as I know Brimar made U52/5U4G type tubes for themselves and for Siltone. Earlier in this tread you can find one where the getter and construction are very much like the Osram U52. I own a Brimar/Siltone logo U52 :)

A while ago we had a small meet here in São Paulo - Brazil (those close friends only meets), where I took my Stratus (SN #003) to be auditioned with my Yulong Sabre D18 DAC. Even having a Orpheus there did not took the light off the Stratus, as most where in line to test their headphones on this...

I have a Raytheon 1461 and was really hoping it would work just to check the wierd look of it with the Stratus :P

  Thank you for the information, Donald. I'll go on upgrading the driver to 6BQ7A / ECC180 tubes.   While you're answering Dubstep Girl question above, could you also let us know if Raytheon 5R4 GY and RK60/1641 work as rectifier tube? I have a few of those lying around here.    

Regarding tube rolling on the driver: can I use PCC88 instead of the 6N1P? I know there are some differences in heater current, but will it damage the amp or just takes longer to heat up?   Any recommendations on other replacements for the driver tube are welcome.

Quote: I saw most of what you done on the page you linked. What have you changed in the analogic stage of the DAC? I found it to be the most important area to upgrade in my experience.

I have a heavily modified DAC Zero, that to me sounds like a much more expensive DAC. Much more...   Here is what was changed in it:   The power supply was reviewed, but nothing really changed. Just adjusted the voltage and all so it would match the standard in Brazil. The IEC was...

Has anyone done the Lawton Tunning by themselves? I'm in Brazil and don't want to send it overseas for the modifications...  

Man, I wish I had discovered this forum when I was 14...