CV for varimu tubes

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rotation

Well-known member
Joined
Jan 24, 2006
Messages
402
Location
slovenia
Hi,

i'm wondering how much CV varimu tubes need in general. There is thread where PRR said that it's more or less -1V/1dB GR for 6BC8 in Altec436.
I just tried ECC189 and 6BQ7, it looked like there were several problems, i could only get very little GR and it also behaved strange. 6BQ7 was much better, i could get around 8dB GR. My control voltage was only(?) -7V.
If -7V is not enough, what i should look for? Is this a problem of output stage? Sidechain is similar to many others, i think i understand it and should work properly.
I know this things are complicated, but i would like to start somewhere, i already have several different tubes to choose from, some transformers and two circuits.

Miha
 
I checked graphs for 6386:
http://www.groupdiy.com/index.php?topic=24961.msg297595#msg297595
Vp/Mu now makes a little more sense, and i found a lot more information, thank you.

I also checked description of your compressor, would you please let me know what Gv means? It is written between this simulator results:
in  dBin    out  dBout    Gv    GR    dBgr    THD    CV    mA

Miha
 

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