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diytube driver board

PostPosted: Sat Sep 28, 2013 10:58 am
by alcors3
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?

Re: diytube driver board

PostPosted: Sat Sep 28, 2013 11:28 am
by EWBrown
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

Re: diytube driver board

PostPosted: Sat Sep 28, 2013 12:49 pm
by alcors3
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..

Re: diytube driver board

PostPosted: Sun Sep 29, 2013 8:23 am
by Shannon Parks
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).

Shannon