Question about pre-amp cap wiring and cap board caps.

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JimiJames
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Question about pre-amp cap wiring and cap board caps.

Post by JimiJames » Thu Jan 05, 2017 6:50 am

Comparing .pdf's of the '67/'68 and '68, I see that the boards pre-amp cap -negative uses either/or free terminal to ground as it does not make a difference there.
Does the wiring have any affect that it is using the other + terminals, that the 10k resistor is on ? Signal is coming in from the other side of the 10k to the other ) terminal...
Should it also be the same, and have same affect wired like the other, correct ?

On the cap board: Axials on the '67/'68 and dual's on the '68 ?
RIP Mark Abrahamian-rockstah -classmate/roommate
RIP Ben Wise -StuntDouble- comrade-in-arms

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neikeel
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Re: Question about pre-amp cap wiring and cap board caps.

Post by neikeel » Thu Jan 05, 2017 5:02 pm

Not totally sure what you mean. If you look at a schem that shows the way that there is a 10k B+ feed first (the one across the board, hooked up to the +of the can and the plate feed for V2 comes off here, then there is the 10k between the two +ves which then hooks up to the plates of V1 (so there is a 10k decoupler between V1 and V2 plates - is that what you mean?
Neil

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Re: Question about pre-amp cap wiring and cap board caps.

Post by JimiJames » Thu Jan 05, 2017 8:18 pm

okay, yes. With your help, think I answered my own question. It just ties in to the other side of the resistor and the signal travels through that path.
https://c5.staticflickr.com/1/502/31290 ... afd6_o.jpg

Question 2 ?
RIP Mark Abrahamian-rockstah -classmate/roommate
RIP Ben Wise -StuntDouble- comrade-in-arms

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neikeel
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Re: Question about pre-amp cap wiring and cap board caps.

Post by neikeel » Sat Jan 07, 2017 2:56 pm

Oh sorry qu.2.

The cap on the board seemed to be single 16in 65 and 66, early 67 went to dual 32 (usually) then continued until late 68 when the preamp can went up top and then the rest of the filter caps.

The ones with preamp can up top and the screens, mains on the board (Pi always up top late 67 on) were/are quite rare.
Neil

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