WOW!!!!
So, what value of pot do I need that will preserve good high frequency response and not bog it down?
So, what value of pot do I need that will preserve good high frequency response and not bog it down?
ruffrecords said:I have not checked that but there will be some increase in noise. If you see my other post you will see the 10K pot is already causing the CF problems so adding a low value pot divider after the CF output cap will only make that worse.
Winston O'Boogie said:Yep I got it, thanks Ian.
So maybe, 1 X 6072 split into the two gain stages, and 2 X 12BH7 Whites?
ruffrecords said:Just checked the dissipation in the CF triode is under 300mW. We could double its quiescent current for another 6dB of headroom.
Cheers
Ian
ruffrecords said:Just checked the dissipation in the CF triode is under 300mW. We could double its quiescent current for another 6dB of headroom.
Winston O'Boogie said:And that might just do it.
If not, re-jig the 6072's to eliminate that 2nd follower and utilise it with another half for a White. Lots of ways we can skin this here cat ;D
BluegrassDan said:Okay. My next course of action is to do as you suggest. 1/2 6072 ---> 12BH7 WCF ----> 1/2 6072 ----> 12BH7 WCF
Winston O'Boogie said:Morning Ian,
sounds good, Dan should be pleased.
One thing that doesn't compute for me is your noise analysis but I think you just used a 1:10 transformer rather than Dan's1:5
Still, with a 3k lower FB resistor it won't be a terrible difference.
BluegrassDan said:In the most basic sense, changing the CF bias resistor to 1.5k will clear up all of the mess? The NF is optional?
I assume I should do the same thing for the second gain stage CF as well? It is identical to the first, although feeding the White follower.
BluegrassDan said:In the most basic sense, changing the CF bias resistor to 1.5k will clear up all of the mess? The NF is optional?
I assume I should do the same thing for the second gain stage CF as well? It is identical to the first, although feeding the White follower.
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