Your opinion on tubes for a PAS3 dynaco preamp

Hello guys ! I reach the end of ma PAS3 restoration... Phono board PC6 modification, adding a new cap board... I will create topics for these restorations...
I'm waiting the alps pot from updatemydynaco, and I'll be ready for the tests !!!
And the most important now... The tubes...
I could read everywhere that it is interesting to use different tubes on the PC5 and PC6 boards... OK...
What do you think about that ??
I manage tu use this preamp in combination with a vinyle LP turntable...
Which tubes would you recommend me ???
Many thanks from France !
Jean-Luc

carcy wrote:Hello guys ! I reach the end of ma PAS3 restoration... Phono board PC6 modification, adding a new cap board... I will create topics for these restorations...
I'm waiting the alps pot from updatemydynaco, and I'll be ready for the tests !!!
And the most important now... The tubes...
I could read everywhere that it is interesting to use different tubes on the PC5 and PC6 boards... OK...
What do you think about that ??
I manage tu use this preamp in combination with a vinyle LP turntable...
Which tubes would you recommend me ???
Many thanks from France !
Jean-Luc

JJ E83CC  on all positions.
This is a framegrid tube, exactly as the TESLA / telefunken framegrid, low noise, linear
and tight tolerances.

And do make sure the riaa components are in accordiance with the Dynaco manual.

Hello Peter and many thanks for your answer !!


And for the 12x4 tube, is there one tube better than another ?

You scare me a little by saying "And do make sure the riaa components are in accordiance with the Dynaco manual." !!  

In fact my PC6 board is modified according to curciaudio



Hey and just a last little question...

I have these caps at 2700pf 500V +-5%...



Is it better or not than the 2 caps 2200pf and 470pf in parallel ?
Thanks

JL

carcy wrote:Hello Peter and many thanks for your answer !!


And for the 12x4 tube, is there one tube better than another ?

You scare me a little by saying "And do make sure the riaa components are in accordiance with the Dynaco manual." !!  

In fact my PC6 board is modified according to curciaudio



Hey and just a last little question...

I have these caps at 2700pf 500V +-5%...



Is it better or not than the 2 caps 2200pf and 470pf in parallel ?
Thanks

JL

Have a look at audioregenesis where some
myths about PAS riaa conformance has been spread.

You might revert your rebuild :-(

Ho it is a sad new...
Do you have any changes for me ?
I do not understand all these schematics and explanations (i'm not in electronics !! lol).
Does it means the original boards and components are better than all the mods ?

carcy wrote:Ho it is a sad new...
Do you have any changes for me ?
I do not understand all these schematics and explanations (i'm not in electronics !!   lol).
Does it means the original boards and components are better than all the mods ?

Yes. That is what George Ronnenkamp says according to the report. He also
goes deep into the sugested mods both as simulations but also with actual
measurments.

then I must reverse everything...

-replace the 95.3k with original 100k resistors
-replace the 2.2Mohm resistors with original 4.7M (or perhaps with 3.9Mohm as mentionned in the article :



-restore the 68pf cap instead of the 820pf and rewire the PC6 to the selector switch...




-and replace (again) the wire shorts with 0.1µF and one of the yellow cap of 0.1µm into 0.05µF (the one below the tube)...






Where to find 750pf caps for the selector switch ? and 68pf (+/-2% ??)

680pF + 68pF = 748pF close enough to 750