Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: joesatch on October 31, 2022, 09:32:42 am

Title: splitting the output of a voltage divider
Post by: joesatch on October 31, 2022, 09:32:42 am
triode has a plate resistor feeding a coupling cap and the coupling cap feeds a voltage divider which has an output to the grid of the next gain stage.  Can this output of the voltage divider be split into two to drive a gain stage in another channel in the amp?  Is there any drawback to this or must there be any modifications done to the divider?
Title: Re: splitting the output of a voltage divider
Post by: Esquirefreak on October 31, 2022, 09:53:23 am
Is one end of the voltage divider connected to ground?

I think it should work, but you'll possibly lose a little gain when splitting the signal in two.

Maybe another way to do it is to connect each end of the divider to the following gain stages? That way you can balance/adjust the amount of signal feeding each next stage with different R values. And if there's too much gain, just connect a shunt resistor from the cap to ground. So you'd end up with 3 resistors in total at that end of the cap. Looking like the PI input cap of a Fender AB763, but in reverse.

Just thinking out loud.

/Max
Title: Re: splitting the output of a voltage divider
Post by: joesatch on October 31, 2022, 10:01:19 am
The divider would drive the second gain stage in Channel one (normal circuit). It would also drive the grid of the second channel triode. This essentially gives me the ability to cascade gain stages in channel two without adding an additional triode.
Title: Re: splitting the output of a voltage divider
Post by: tubeswell on November 01, 2022, 05:27:51 pm
triode has a plate resistor feeding a coupling cap and the coupling cap feeds a voltage divider which has an output to the grid of the next gain stage.  Can this output of the voltage divider be split into two to drive a gain stage in another channel in the amp?  Is there any drawback to this or must there be any modifications done to the divider?


It all depends on what the signal phasing is like in the other channel
Title: Re: splitting the output of a voltage divider
Post by: DuaneOh on November 01, 2022, 06:21:17 pm
A schematic of what you are asking about would be helpful.
Title: Re: splitting the output of a voltage divider
Post by: kagliostro on November 02, 2022, 03:19:21 am
Quote
It all depends on what the signal phasing is like in the other channel

Why  :w2: :w2: :w2: :dontknow:

I don't think he intend that the signal of the second added channel Is furtherly mixed with the first Channel

Franco
Title: Re: splitting the output of a voltage divider
Post by: joesatch on November 05, 2022, 10:20:35 am
no schematics i just put this all together as i went. 3 channel pre.  Clean, BE, Slo.  I did have success in splitting the voltage dividers using relays that would disconnect the unused lead when switching channels. it all works