100k pot before V1 on 5E3?

[timmyjoe]

What would happen if I changed the 68k resistor for a 100k pot on the 5E3? Would this create useful gain control? Or are those resistors used for another purpose?

My end goal is to have the 5e3 work more like a two channel amp. I'm planning on getting a ABY selector switch to run two different channels. I'm loving the tube distortion of the amp and not liking pedals. My thinking is that I could turn down the resistance and work that tube more for lead guitar. Then use the regular volume controls to balance the volume between channels.

[JB]

That won't give you a gain control, the 68K's are grid stoppers, or for the lo input they work together as an input 6dB attenuator.

I think the 5E3 is best at doing what it does stock, warts 'n all, and modding it for two channels, master volume etc. detracts from that character.  However I guess you could try splitting the V1 cathodes and having differing bypass cap's.  Maybe put a pot in series with one of the cap's to give you a bit of gain control.  You could also experiment with different coupling caps to give different tone between them.

[HotBluePlates]

... Would this create useful gain control? ...

If you add a Volume/Gain control before the first tube, you will erode the amp's signal-to-noise ratio.  Noise will stay the same, but guitar signal will be reduced.

[66Strat]

Do you use the volume control on your guitar? Set the volume/tone controls of the amp to get the distortion sound that your after with the guitar volume at or near maximum. Then just roll back the guitar volume to clean up the sound when needed. Also, there is a LOT of interaction with the tone and volume controls that can be manipulated to your advantage in finding your sound. The attached video provides insight on how the controls interact.
https://www.youtube.com/watch?v=VN2vqCxaeC0

[Willabe]

My end goal is to have the 5e3 work more like a two channel amp. I'm planning on getting a ABY selector switch to run two different channels. Then use the regular volume controls to balance the volume between channels.

You'll have problems doing that.

Like 66Strat wrote, the volume controls are interactive on a 5E3. Turning the volume on the channel your not plugged into greatly effects the channel you are plugged into.

Look at the link 66Strat posted.

Also, there is a LOT of interaction with the tone and volume controls that can be manipulated to your advantage in finding your sound.

[HotBluePlates]

My end goal is to have the 5e3 work more like a two channel amp. I'm planning on getting a ABY selector switch to run two different channels. ...

This doesn't work for these amps as they sit except to wind one Volume full-up, and turn the other Volume halfway-up.

The "two channel" notion works when you have a master-volume amp, which a tweed Deluxe very much is not.