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Queston: C1 cap value for Poseidon
Posted:
Sun Sep 23, 2007 3:08 pmby logos47
Dear Shannon, The MKIII Poseidons are installed, stuffed with nice Allen Bradleys along with some AudioCap Thetas salvaged from a previous project. Question is, the C1 cap value I have inserted is .47uF instead of the .22uF specified. Do you see any long term problem with this?
Bob
Re: Queston: C1 cap value for Poseidon
Posted:
Mon Sep 24, 2007 5:42 amby Shannon Parks
logos47 wrote: Question is, the C1 cap value I have inserted is .47uF instead of the .22uF specified. Do you see any long term problem with this?
No problem. For the C1 coupling cap, bigger is better. We want this stage to have the dominant pole or low frequency cutoff. Note that this is not true of the second stage.
Posted:
Sat Feb 02, 2008 1:08 pmby JW34
Concerning the C1, C4 & C5 caps.....can these be Film & Foil istead of Metallized? I am planning my project and would like to use Hovlands.
Thanks,
Jay
Posted:
Sat Feb 02, 2008 3:23 pmby Shannon Parks
Yes.
What would be the optimum value for C1?
Posted:
Wed Feb 20, 2008 9:45 pmby EdStiles
For C1, I have 0.22 mfds, 0.33 mfds and 0.47 mfds (all 630v) available. What are the trade-offs? Which would be optimum? I'm using Ned's version of the Poseidon, optimized for 5751s and 12BH7s.
Thanks,
Ed
Posted:
Thu Feb 21, 2008 6:48 amby Shannon Parks
Whatever fits in there best, Ed. There won't be a huge difference between the three, but the larger caps will be a ever-so-slight technical improvement.
5751
Posted:
Thu Sep 04, 2008 6:44 amby logos47
Ed, I saw you mentioned the 5751 and optimizing the board for that. I love the sound of mine, but just plugged 'em into the 12AX7 postion. Any tricks of the trade you can share?
thanks, DrBob
Re: Queston: C1 cap value for Poseidon
Posted:
Thu Sep 04, 2008 12:27 pmby Wiesiek Lipowski
separks wrote:logos47 wrote: Question is, the C1 cap value I have inserted is .47uF instead of the .22uF specified. Do you see any long term problem with this?
No problem. For the C1 coupling cap, bigger is better. We want this stage to have the dominant pole or low frequency cutoff. Note that this is not true of the second stage.
Is this C1 really necessary here? There is no cap in the MKIII upgrade article by Kara Chaffe, Audioxpess 2001. The topologies around the first tubes (12AT7 in Kara's) seem to be similar.