diytube driver board

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diytube driver board

Postby alcors3 » Sat Sep 28, 2013 10:58 am

Page 10 of the tube zone diy manual has this "IMPORTANT: A 1K resistor goes from Pin 6 to Pin 5 on each EL34 socket - the amp
won't work without these installed. No other connections should be made to pin 6
or 5 on these sockets."
But the schematic shows J1 J2 J22 and J23 all going thru a 1K resistor to pin 5. I have done this by running a wire from each J to pin 6 on each EL34 socket. This contradicts page 10 of the manual..
Which is right?
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Re: diytube driver board

Postby EWBrown » Sat Sep 28, 2013 11:28 am

Pin 6 is just used as a convenient tie-point, as it has no connection inside the EL834, connect the 1K resistor between 5 and 6, then the output from the driver board to pin 6, this places the 1K grid stopper resistor in series with the control grid (pin 5).

An alternate approach, depending on your final layout, is just to connect a 1K resistor between the drover board outputs, and to each EL84 control grid (pin 5).

It is probably better practice to place the grid-stopper close to the grid connection, so placing it between pins 5 and 6 would be the better choice.

/edB
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Re: diytube driver board

Postby alcors3 » Sat Sep 28, 2013 12:49 pm

EW thanks
I wonder if the wording in the manual should be changed, the statement that the resistor is placed between pin 5 and pin 6, and there should be no other connections to 5 or 6, did give me pause..
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Re: diytube driver board

Postby Shannon Parks » Sun Sep 29, 2013 8:23 am

alcors3 wrote:Page 10 of the tube zone diy manual has this "IMPORTANT: A 1K resistor goes from Pin 6 to Pin 5 on each EL34 socket - the amp
won't work without these installed. No other connections should be made to pin 6
or 5 on these sockets."
But the schematic shows J1 J2 J22 and J23 all going thru a 1K resistor to pin 5. I have done this by running a wire from each J to pin 6 on each EL34 socket. This contradicts page 10 of the manual..
Which is right?


Ned's note is 100% correct and the drawing isn't necessarily wrong. I think I drew the schematic that way to make sure pin 6 isn't seen a tube connection (since it is just a tie in).

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