master volume for 5E3

[k51502]

does anyone have a layout or schematic for fitting a master volume to a 5E3 deluxe.a ppimv is good but i would prefer a mv that lets me get maximum pre-amp gain ala modern marshall etc.
also can anyone recommend a good way to go to a single input utilising all available gain stages,again a layout drawing would be prefered as i only have a basic knowledge of amps,explaining it to me might not work but a drawing says a thousand words.
hoping someone can help

thanks

karl

[Steve Conner]

Err, sounds like you want a SLO clone in a 5E3 cabinet? In which case, build that.

[Jammin'John]

A 5E3 doesn't need a MV.
It has a 12ay7 in v1. VERY low gain.
There is only 1 preamp tube.
If you sub a 12ax7 and plug into the bright channel you will have a lot of overdrive.
The bright channel already uses all available gain stages.

JJ

[Bruce / Mission Amps]

Originally Posted by k51502

does anyone have a layout or schematic for fitting a master volume to a 5E3 deluxe.a ppimv is good but i would prefer a mv that lets me get maximum pre-amp gain ala modern marshall etc.
also can anyone recommend a good way to go to a single input utilising all available gain stages,again a layout drawing would be prefered as i only have a basic knowledge of amps,explaining it to me might not work but a drawing says a thousand words.
hoping someone can help

thanks

karl

I've never tried this but I don't see why you couldn't use a dual gang 250K audio pot in place of the two grounded 220K grid load resistors on the 6V6s.
Ground the low side of each pot section (far left as viewed from the rear of the pot) and feed the top lug (far right as viewed from the rear of the pot) with signal from your .1uF coupling caps and then connect the middle lug (wipers) to each respective 1500 ohm grid stopper resistor on the 6V6 sockets. I'm not sure you'd need it but maybe use shielded co-axial wire to and from the pots. RG174 works fine.
On the 6V6 tube sockets, you might want to strap a 680K to 1M resistor across each grid to ground just to be safe in case a pot fails... (never seen that but someone here will mention it if I don't).
Now, you could also use a 12AX7 in place of the 12AY7 but you might have some volume and overdrive issues that will be hard to control with your standard volume pot.
Seems to me that the old SOVTEK 12AX7WXT+ preamp tubes had about 15% to 20% more gain then any other 12AX7 I've heard.
Old RUBY Silver Special 7025STR Chinese 7025s were excellent too.

[rexindigo]

check out the mastervolumen variations at 18watt.com, its made with a double pot wired after the PI. I Didi it to my 18Watt Clone but to be honest i like the sound best when the Master is way up because these classic amps live from the Power tube saturation...
But its still better to have it after the PI then somewhere else in the signal chain, because you get a little of the PI Overdrive as well ;-)