Ruby bassman with headphones

[aballen]

My first ruby works great,  I decided to see how small I could make my next one.  As you can see it is pretty small.  So small in fact I could not fit a battery in the box and I had to eliminate one of the pots.  Well the bassman mod was perfect because it requires replacing one of the pots. 

I had to insulate the headphone jack from the box and now it sounds great.  It is very responsive to the volume knobs on my guitar as well as my picking.   Louder or stronger picking creates a nice bit of distortion.  And lower volume or softer picking plays sparkly clean.

This brings me to my problem, and I'm not sure if it is a problem or by design.  The volume pot on my ruby seems to have no effect,  I have not tested through a cabinet... I don't have one.  Th volume through my headphones is just fixed.  I'm thinking I should replace the pot... But I'm wondering of this is just caused by using a headphone jack with a 220pf cap across pins 2 and 3.  Or maybe this is just how the headphones work in this circuit... I have a stereo jack with a 47 uf cap.

Should I replace the pot or look t something else?  As I said it sounds great... But the fixed volume through headphones has me stumped.

[artifus]

Bassman
Replace the .047uF cap from the FET source pin to the volume pot with a 0.1uF. Place a 220pF cap from lug 3 to lug 2 on the volume pot. Remove the Gain pot and place 2k2 fixed resistor between pins 1 and 8. In this configuration, Ruby sounds very much like an old Fender Bassman to our ears. With the Volume control at half rotation and below, you'll notice smooth and sparkly cleans with good depth. With the Volume pot set high, you'll hear nice overdrive that is great for blues playing. The transition from dirty to clean can be controlled with your picking or strumming. This aspect can add an extra dimension to your playing.

this?

the volume pot should shunt the signal to ground at one extreme of its rotation preventing the 386 from receiving any input at all and therefore no output with variable input level between the two extremes of rotation. hope that makes sense. *goes to brew more coffee*  ie, it should work as a volume control. check your pot wiring.

[aballen]

That is it from runoffgroove.com

I'll check the pot wiring tonight, thanks

[aballen]

Well according to the schematics it is wired correctly.  I checked my other ruby and it is wired the same way.... It has to be the pot right?

[artifus]

according to the schematics

do you have a multimeter?

[aballen]

of course I do  D:

What should I check?

[aballen]

still have the same problem.  I've pulled apart s few things, re-soldered them in.  I'm not sure what could be wrong.

If anyone has any ideas, let me know.

[artifus]

any joy with this?

first use the multimeter to check between the volume pot and ground, the volume pot and pin 2 of the 386 and then the volume pot itself. you say the volume pot has no effect. the schematic says it should. check the integrity of the pot, the connections to and from the pot and for any shorts that may compromise the pot.