Dual Bias or Bias and balance

[Ed_Chambley]

I am going to use this layout, but I put bias controls on the back with probes.  What do you think would be the best setup.  To separate into dual bias, or a bias/balance?  NOS 6v6 singles are cheap.  I will have a 50v bias tap PT.

[Willabe]

NOS 6v6 singles are cheap.

                            Where?              

Less than 6L6's or EL34's, but still.....       Ed did you win the lottery and not tell us????      


I like the idea of dual bias, but it can be a pain to work it in space wise.

Edit; just saw you wrote singles, sorry.

[RicharD]

Either dual or balance is fine.  Depends on if you want them independent of each other.

[FYL]

I prefer bias + balance - it's easier to dial-in the right voltage - but dual bias pots are OK.

[Fresh_Start]

I prefer bias + balance - it's easier to dial-in the right voltage - but dual bias pots are OK.

Do you have a schematic of the bias & balance circuit that you like?

Cheers,

Chip

[Ed_Chambley]

I prefer bias + balance - it's easier to dial-in the right voltage - but dual bias pots are OK.

Do you have a schematic of the bias & balance circuit that you like?

Cheers,

Chip

No, I do not have a schematic, have you seen one?

[Fresh_Start]

I prefer bias + balance - it's easier to dial-in the right voltage - but dual bias pots are OK.

Do you have a schematic of the bias & balance circuit that you like?

Cheers,

Chip

No, I do not have a schematic, have you seen one?

Kevin O'Connor has one in "The Ultimate Tone" Vol. 1 IIRC but it looks really hard to figure out what the component values need to be. 

I've attached one that I saved in 2010 based on this thread:
http://www.el34world.com/Forum/index.php?topic=8863.0

Note that FYL offered up a circuit there, so he responded to my request before I asked!  Actually, I ought to bookmark that thread so I can find it again when I want it.  Elegant French is just so... elegant!

Cheers,

Chip

[Ed_Chambley]

In reviewing the schematic, it shows creating adjustable bias, the balance from the PT voltage.  If you had a bias tap of 50v and were using 6v6, would the wiring be the same except you would not need the 120K resistor?  What else would need revised.  I am assuming the pots are connected center lug to center lug.