2. amps-preamps
  3. 1138726066

Tubes and microphonics

I want to know when microphonics affect the sound.
I have a Sonic Frontiers Line 2SE Preamplifier. I tried many tubes like Valvo, Siemens, Reflector 6H23NEB.
Recently I bought two matched pair of Amperex 6922PQ White Label Made in USA. I think that the Amperex are better than the others, but I could see that they are less silent.
When I knock the cover of the preamplifier I can hear the knock clearly in the speakers. That not happen with the others tubes. The 6H23NEB are the most silents.
I think that Amperex have more gain than the others. But I don´t know when that is critical to the sound.
Please let me know your experience with your tubes and preamplifiers.
Thanks,
Pablo
elduende14
yioryos's avatar
yioryos
723 posts
 
Guys
Can anybody tell me their opinion for the Amperex PQ orange label USA late 60's early 70's production?Need for the SF SFD 2MK2 Dac.
Elduende 14,sorry for highjacking your thread
Marco you should know any comments?
Thanks
George
jax2
3,031 posts
 
Sorry George, no experience with that specific tube that I can recall. Mostly compared the German tubes in that family. My favorites in the application I was using them in were the Siemens CCa's.

Marco
s23chang
617 posts
 
Siemens 7308 is dead quiet.
yioryos's avatar
yioryos
723 posts
 
Thanks guys
Marco the NOS Siemens CCa must be expensive ,no?
George
jax2
3,031 posts
 
George - Unfortunately, yes, they are quite expensive and sometimes counterfitted or sold in less than desirable condition for large coin. If you go that route definitely go with a reputable resource. Expect to pay $75-150/tube (crazy!). Alternatively, in current production (or NOS if you like) I'd give a try to the Russian Rocket tube, I think they are 6H30 and are drop-in for most 6922 applications, but take care in which variety of that tube you use. I think BAT uses them in their gear. Worthy of a listen and much cheaper than NOS. YMMV and check on the application with your specific piece of gear.

Marco
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